I purchased a 15 HP Johnson in 1982 in Manaus Brazil to use in upper reaches of Amazon tributaries. It was a factory modified motor based on the 10 (9.9)HP motor with the stouter lower unit from the 25hp model. It had a heavy duty low pitch propeller. The advantage was that it was light weight enough to haul it up some of those 50 ft high river banks. We mounted it in a 21ft aluminum boat and travelled 10 days for our first trip to an Indian village. We put on several thousand miles of travel with that boat and motor before it was stolen. But it was a good reliable motor - not fast, but it pushed a load of 1100 kilos easily. We often had to jump over logs, and under logs to get upstream. Thanks for bringing back a fond memory!
A 9.9 to a 15hp. One of Johnson's little secrets to keeping their product line up. My Dad worked at the Waukegan plant for 33 years. He told me this secret years ago.
Thank you very much for your video. I just purchased two 9.9 Johnsons (a 1975 and a 1976), and with the help of your videos I'll have no problems tearing them down and making them as new as possible! Thanks again, stay safe. Watching part 2 right away!
Stephen C Foster park near me has a 10 horse limit on boat motors so everybody used to buy 15 horse and order a 9.9 cover to conceal their deception. The Rangers wouldn't look too hard back then if you weren't causing trouble. The first 2 digits of the vin plate is usually either 9.8, 9.9, 10 or 15, and you can change the 15 to 9.8 if you're careful and smudge the whole plate a little. Just a little outlaw fun from back in the day.
Mike I was a master tech on OMC AND Johnson/ Evinrude outboards back in the 70s thru the late 90s. You are correct on the conversion from 9.9 to 15 hp. I you check the parts manual for your model year you will find that there is a shim that is fitted under the reed plate that will allow the reeds to open a bit further which in turn allows for the extra fuel. Also the difference in carburetors is the size of the venturi.
Always agree, when you purchase something used, check and change oil, plugs.fluids, filters, etc so you have a starting point of your own for future maintenance.
That water tube grommet that you said doesn't look right is just a different style that was used on those outboards especially, to make it easier to get the copper tube guided into the grommet...it is a wide mouth grommet and will work on most any Johnson Evinrude. I use them when I can...they help prevent the grommet from folding over and obstructing flow as it is nearly impossible to see if you have the tube IN the grommet when sliding the unit up into place on some motors. Great, no nonsense, helpful video for folks doing this for the first time.
We had an Evinrude dealership in the 80's. (Roshway Sales and Service, Dryden Ontario). Same parts book and service manuals for the 9.9 & 15. I don't remember the parts book listing different carbs, but I do remember it listing different cylinder heads. (And I suddenly remember I'm gawd awful old)
I just bought my first boat, a 14 foot that came with a free 1994 9.9 Evinrude 2stroke. Guy said it had very very low hours but didn’t run. I had to fix a couple wires that were chewed from mice. The air box was packed with acorns, and the carburetor was thoroughly cooped up. I took it all apart, cleaned the carburetor,got the Jets passing air, put it all back together and it fired up on the first pull, purrs like a kitten. My one concern, it seems to not squirt the fresh water at idle but does very well when throttled up slightly🤨 I hope it’s not a problem. I’ve only ran the motor 2 times for a few minutes so far, haven’t taken it out yet. Your video would’ve help me a lot if I saw it before I did all the work 😂
Hi Michael.......greetings from Australia. Just inherited a 9.9 Johnson and knew nothing about it until now. Many thanks for sharing your knowledge and indeed your friendly presentation. I am confident I will now be able to repair and use it as an Auxiliary motor for my boat.
When grewing up one of my neighbors at the cottage had a 9.9 hp, but in fact was a 15 hp with 9.9 badging. They are exactly the same size. He won the 10 hp and under catagory at our local Regata for years and has a shelf full of trophies to boot.
I have owned a 1982 15 hp Johnson for 20 years...the 9.9 and 15 hp motors were exactly the same. All parts were I nterchangeable.The only difference between the two motors was the jetting in the carbs and the timing.The 15 ran at a little higher rpm
Back in the 80's I bought a used 15hp Evinrude and replaced the decals with 9.9 decals so I could run it on our local "below 10hp" lakes. The serial plate on the mounting bracket still said 15hp but i was never checked by the game warden......I just never opened it all the way....LOLGreat little motors.
I think if you look around Canada you will find thousands of that year or model in Evinrude and Johnson outboards. They seem to be a bullet proof little motor! I enjoyed your presentation! Hello from Canada! Please stay safe!
Just now seeing this video. My man is giving really good info. Helped me a lot to figure out an old motor. I like knowing what I am working on before working on it and seeing others break it down helps. Thanks for the video!
Hi. As long as I can remember the 9.9 Hp and the 15 Hp were the same engines with the 15 just boosted (sorry I was early). In my book at first look this 88 is still a beauty .Being that old the main problem will be the rubber parts craking. These were the last years of the best quality engines and Envinrude-Jonhson ruled the water for their no nonesense Chevy style. Good luck
Good day, a correction should be made about proper mounting height of the outboard. The anti-ventilation plate {the wider wing on each side of the gearcase}, should end up between flush with the center bottom of the hull and up to 1.5" inches below it. If it is mounted any lower it will act like a hook and create drag, or if mounted higher the prop will over ventilate and you may end up with less water being sucked up by the water pump. This rule may be different with boats set up for racing, but they also different or modified parts to achieve the desired result.
Just so you know, I didn’t think you were “long winded”. You made sure we in the audience understood where you were and where you’re headed. I have a 1990 Johnson 8hp. I o all my own work as well. Thanks. Headed to Part II .
You can fix that horrible crack in your floor very easily - get a roll of foam backer rod that will fit and some self-leveling caulk at your local masonry or big box lumber yard. Push the foam into the crack - can use a couple of rows on bigger cracks - and then fill with self-leveling caulk. It will sometime form a big bubble but just pop it when it does and it will level itself out. This is what we do in commercial construction jobs when we have this problem. If you want a concrete finish, then use self-leveling concrete. You can use it instead of the caulk or over the top of the caulk by leaving it down a little bit below the service, a half-inch should do.
Same Block...parts are interchangeable...I put these on more sailboats than I can remember...lol....I took a 9.9 all over the South Pacific...Half a pull and my motors start and go..Damn good motor and easy to maintain...Dont let anybody tell you different.
Walter here, on my wives page. I just found your page and will now be a regular viewer. I like and appreciate what you are doing. This kind of help is something I believe we can all gain from. Thank you for it. I recently picked up an identical 9.9 and thankfully it runs like a top! I'll soon be playing with an 85 horse and will be using info I gain here to help me.
Thanks for these videos. I bought a little skiff a few years ago that has a 15hp Evinrude, of the same vintage as yours. I believe they are the same engine, just blue instead of white. Your videos will help me in getting it running again. Thanks again.
Why do I watch this? 😆 Nice channel. Now I have another subscription to go along with the guy who digs junkyards for cars to fix and the bus grease guys😃. It is all so interesting.
I've got a 91 9.9 electric start long shaft, thing runs great.. matches my 1990 60hp tiller. The value of these old 9.9hp motors are up, pd $300 for mine.. will easily sell for double
I have a 9.9 evinrude outboard ,I found out that pulling the flywheel makes it easier to remove and replace thw pull starter , I like your vidoes thank you keep up thegreat work .
@@Michaelsbackyardmarina you are welcome , I would like to know where you are located please . I have miht have 2 outboards I would like to possibly trade for one good prefer at least 20 hp
Converting a 9.9 OMC to a 15hp but keeping the 9.9 cowl was fairly common in New Jersey where many fresh water lakes are legally limited to 10 hp. At some point the newer 9.9 motors were changed and unable to just change carb to convert to 15 hp.
Getting dad's old 9.9 Johnson and '57 Johnson 7 1/2 he bought new like the 10hp. Mine is a 1980 maybe. I subscribed and probably will contact you when they arrive. Had them shipped from Maryland to CA. Arrives tomorrow or Tuesday hopefully. May do your upgrade to make it a 15hp. Many thanks for your video. Steve
When you pulled the carburetor you said the screw on the cam follower was for 'idle' adjustment which is wrong. It is for "synchronizing" how far advanced the timing is when the butterfly in the carb begins to open. The idle adjustment stop should be on the outside of the motor by the throttle tower/back end of tiller mount area.
@@Michaelsbackyardmarina Yeah, but people as recently as half that have replied and who knows how many have not, but have trusted your 'mistake'? Perhaps, if possible, to pin this reply string as an addendum instead?
You will find the 9.9 and 15HP are identical in all areas except the 9.9 carby is a detuned 15HP, they do this by adding a sleeve in the venturi tube and changing the jet sizes, kits are available for this purpose maintly aftermarket suppliers, but this is also common with the Mercury 7 and 10HP as well as afew other motors...
i have a johnson 9.9 engine short shaft, the last pull on the recoil rope on the lake recently resulted in the rope no longer recoiling, Luckily the boat engine started and i got it off the lake. Despite that i like the johnson engine.
In our region ,we have hp restrictions on many lakes, often 9.9 or under.. so .. cowl off of 9.9 on 15hp usuually works ok ..unless the Conservation officer checks the motor tag..
In Washington state - where I am , there is a " 10 hp " limit on lakes , some people got decals or a 9.9 hood....on their 15s.... I bought a 1990 Evinrude 15 short shaft brand new.... I paid $1399.00 for it.... those were awesome motors.....The throttle cable broke on mine when it only had a couple hundred hours.... of course the previous years had a gear to gear throttle system.... I loved those motors though.... that 15hp rapped out to 7000 rpm.... and it woul d run that speed nonstop for as long as you wanted....
@@Michaelsbackyardmarina I recall mine cost just under $30.00 ... in mid 1991.... I probably had 200 hours on the motor at that point...in salt water / Puget Sound .... It was a bit of a chore putting it i n... the idle adjustment is part of the whole thing and was finicky the first time through....
I thought you should know - although the Comet cleanser has no abrasive, the Magic Eraser sponges DO have embedded abrasives. That's why they work so well - but they can leave fine scratches, so go easy with them.
My impeller would not slide off either. The shaft was caked with old grease that had hardened. Had to use a brash brush and carb cleaner to get it off.
On these motors under power head there is a rubber grommet on copper water pipe from water pump. Many swell closed in salt water. Motors would overheat. Clean around grommet and put anti corrosion grease on aluminium. Did dozens at dealership 7.5-15 same motors. Good motors
I also bought a 9.9HP motor only to find out, much to my delight, that I had a 15HP motor. Many owners found out that taxes were higher for 15HP motors than for 9.9HP motors so cover swaps occurred. The covers were an identical fit for either motor. Cheap swap.
They also did that because some lakes have a 9.9-10 HP limit on them (15HP on the down low); they just had to hope the person inspecting the boats and motors didn't know the model year and HP are part of the SN on every OMC outboard.
I have a 15 foot aluminum boat and the only time I ever had to paddle was when I ran out of gas, (I will never, leave without a full tank again). Even though my fishing buddy was on the other oar in my opinion that ordeal was tougher and more disagreeable than demolishing a boulder with a plastic picnic knife.
Just a heads up, when you were discussing where to measure from mounting on the boat, you referenced the wrong plate for being even with the bottom of the hull. The cavitation plate directly above the prop shaft is the plate to be even with the bottom of the boat.
the first thing you do is simply look at the model #... that will tell you the year and HP right away. for good measure, check the freeze plug on the block. takes 2 seconds. also, you keep the cavitation plate even with bottom of boat, not the upper lip of the motor.
Mike I really enjoyed the video of you working on this motor I sent you another request of information and I hope you answer but thanks for being online I will continue watching thank you
The only years that the 9.9 and 15 were identical except for the carburetor were years '74 to '76. After that the intake and exhaust manifolds were different; just changing the carb won't be a full conversion. Also, you said there was silicone under the water pump; I believe 3M-847 sealer should be applied there when you have a metal water pump. Per Evinrude's website the QL77JC4 plug should be gapped at .030, although the NGK equivalent does call for .040 It really sounds like the shop that the previous owner took it to cheated him big time.
@Russ Gallagher In 1979 they added a shim, part #325038, (one for each cylinder), behind the leaf valves and under the stop plate for the 15 hp, apparently to allow leaf valves to open up more at higher RPM, giving the motor more fuel in the air mixture.
@Russ Gallagher Yes, obvious typo. The point is that there's more to getting 50% additional hp than just a bigger carb. I've heard that the early motors were more like 13hp from the factory. And that's only at WOT, anything less than wide open and you have a 9.9 that doesn't idle well (I had a 1974 Evinrude 9.9 with the 15 carb, changed it back to 9.9).
I replaced fuel pump and recoil spring good gas. Still wouldn't start. Checked my gap and it was set at 28000 regapped to what you said 40000 still didn't even try to start. Went and bought new plugs Ql77jc4'. Checked gap and it was preset at 25000. Put the new plugs in and guess what ? Never ever heard it run so good. Checked online and 30000 is on the chart for this motor. Not sure what up just glad to finally getting it running. Was a nice video though.
Ove Your little shop and Love Outboards , We use to run an 9.9hp evinrude in my youth and at that time there was a laws that you needed i liscence for run over 10hp so i eard that they actualy turned 15hp to 9.9 by caurburators exchange so the Manufacturers would have a better market.
If you wet the durface beforebyou apply the Vomet and let it sit undisturbed the blesch will go to work. Im 80 and been resurecting ild machines since I was a kid.
Back in day you could have a 15 from a 9.9 by changing the carburetor to 15 hp size. The engines in each series could lower or elevated by changing carburetors to each hp. 9.9 to 18 was one. 25 to 45?? 55 to up.
Always remember that to get the extra power the engine must rev higher, the exhaust tube and spark advance must be swapped over for the tuning to allow the additional revs. The 9.9 is actually better at lower revs and idles much better and otherwise makes the same power to 5,500 rpm - the uprated p[ower comes from the power head revving out to 7,000 rpm at WOT. Because the 9.9 is an engine rated to rev out past 7,000 rpm it is virtually unburstable at 5,500 and loves running WOT all day.
A 9.9 is a 9.9 because some lakes and operator ages are limited to "below 10 hp." Often a 15 has the 9.9 cover on it. And yes, a 9.9 and a 15 are usually identical engines as you explained. That is a nice little outboard.
True... Most of the 9.9's I know of are a 15hp with a smaller carburetor to restrict the power down to 9.9... Oldest trick in the book is to get a 15 carb off one with a junked bottom end.
Just to let you know - those years of Evinrude and Johnson have a problem with the water tube grommet at the power head. The problem shows sooner in salt and brackish water. What happens is the Grommet swells up into the water port at the power head and stops the flow of water from the pump. The new grommets are made a little shorter above the internal groove to stop the upwards swelling.So if your motor blows steam out of the the indicator port for the water pump now you know why. I was the first mechanic to diagnose this problem. there is a service bulletin for this problem.
I had a 25 hp Evinrude and it had steam coming out of the exhaust even though it was peeing good. Now I know what the problem is. How hard is it to get to? Can it be accessible once I pull the lower unit?
@@Dangbo3030 No you have to remove the power head then you will be able to get at the inner exhaust housing which holds the water tube and grommet to the power head. But if the tattle tail stream is peeing water steam in the exhaust is normal.
Thanks for your video. My 13yo son just bought a 1977 Johnson 15HP. It has low compression in both cylinders (65 PSI) and no spark. We are pulling it apart and trying to get it going. Tested with a voltmeter and found good charge to power pack and nothing beyond. So ordering a new powerpack. Next we took the head off - the head gasket looked OK but we found the thermostat was rusted. Piston rings look OK too. So not sure why compressions is so low in both cylinders. Anyway - really enjoyed your video thanks.
Happy I found your video, I think it confirmed what I was suspecting about my 60hp of the same generation (1993). I had noticed the owners manual shows the 60hp and 70hp have the same displacement and I thought it must be pretty easy to convert the 60 to 70 if the block was the same. I wonder if anyone has done the conversion for that motor and if its the same parts to change (carburetor and reed plate spacers).
From a marine technician to you having worked in the industry for 26 years 10 of them for an OMC dealer there’s no way that’s not the original impeller and whatever parts they gave this aren’t from this motor. impeller wasn’t melted but the rubber was laid over like it been that way forever ,and the keyway was stuck.
@@Michaelsbackyardmarina You’re welcome good work and good channel if you’re ever interested I have lots of marine parts .I started out working for an old timer who is now 89 and he specializes in old motors that large dealerships wouldn’t work on he taunted us to repair things not change parts . He was a stickler for no come backs PS I have subscribed to the channel 👍
Thanks u showed me how to take apart my bottom end off my 61 18hp Johnson that runs great I think I have a seal lacking in the gear box I've had water in it when I changed the oil and there a oil spot when I put it in the water and it doesn't like to run in low rpms in gears
Our '62 OMC Gale 15 HP is the same motor. Split the lower unit after draining. The O ring seals in your prop shaft are probably long deteriorated to nothing, replace them. OMC did not use RTV Blue when they made these in the 60's but if the motor lower unit has hit any rocks and stumps at speed, in it's life, the rubber gear case seal could be leaking also. Put RTV Blue under the seal as well a small bead on top of it to insure it's water and oil tight. Back then OMC used fiber gaskets on the gear case filler/drain screws; mid 70's changed to thicker rubber ones. Any oil resistant gasket material or rubber washer will work; add RTV Blue to insure seal and to keep the screws from coming loose from vibration. Let the RTV Blue dry 2-3 hours before refilling with gear oil, unless temps are over 80° F, 1 hour is long enough. Low speed carb adjustment needs to come out 1/4- 1/2 turn or the jet is clogged or just worn out after so many years. Try opening 1/8 turn at a time. If that doesn't help check/add/change the fuel line filter and the low speed jet.
Mike I have a 69 Johnson 20 HP Johnson that I recently bought. It is very clean and runs like a champ in a barrel. When I put it on my boat and put it under load it kept jumping out of gear. I can't find anyone to look at it. Any ideas on what that could be. I don't feel comfortable just jumping in and trying to diagnose it, but If I had an idea of what it likely is that could give me a starting point and I kind of knew what I am getting into, I might take the plunge. Thanks, Paul
15 hp not only has a bigger bore carb. but also has a leaf plate shim and a tuned exhaust and that's the difference between a 9.9 and a 15. 15hp carb. part # 391654, 15 hp leaf plate shim part #325038, 15 hp exhaust tube part # 325333
Good video, very helpful and informative on John 9.9 Hp engines. Just one thing you are incorrect in where you are measuring the length of the shaft. The measurement starts from the cavitation plate directly above the propellor, from what I see you are measuring from the lower fin above the cavitation plate. Using your measurement will put the caviation plate about 3-4'' below the bottom of the boat and affect the planing characteristics & steering of the boat. The cavitiation plate should ideally be flush with the bottom of the boat but no more than a 1/2" variation up or down.
As for the rubber pull handle, depending on the model year, some used a 3/16" - 1/4" flat washer just under the knot others used a small galvanized steel plate with a hole (about .3" x 1") under the knot to prevent the starter rope from pulling thru depending on the rope size/ motor HP.
A good 2 Cycle Outboard tool kit should have: 1/4" -3/8" Flat Tip screwdriver, Combination Pliers, Spark plug Wrench, Electrial tape, 1-2 Prop shaft cotter pins, 1-2 prop shaft Shear Pins, 2 Spark Plugs, 2-4 zip ties. As I remember correctly, the model year is the first or last 2 numbers of the SN; note that both Evinrude, Johnson and Gale was made by OMC and almost all parts are interchangeble. Note the Data plates are the same shape, size and location with the name being the only difference. As I worked in the assembly plant and as a Crankshaft Grinder later I know a lot 1.1 to 70 HP OMC outboards. We have a 1923 1.1 HP Elto-Evinrude that still runs great after replacing the plug wire and coil in '88.
Shaft length is measured from where the clamp meets the transom to the bottom of the anticavatation plate just above the prop, not where you showed it.
A 9.9 is the same size / weight and displacement. Only difference is carby and kw magneto pushes out. According to brochures on evinrude and Johnson. The cavitation plate needs to be about an inch below the keel actually.
I have a 9.9 Johnson 1984. I purchased this motor brand new and as such have had it it's entire life. Believe me go back to the Champion plugs. Mine still runs as good as new.
That’s really awesome!!! Maybe this year I have two Johnson’s I will be working on...my first experiences with boat motors. I had no idea about the change from long to short shaft.
I wish it was as simple as that nowadays... I have a 15hp 4 stroke Suzuki. Identical to the 20hp except they put a restrictor plate behind the intake, and the timing is different. Only way to step it up is to change the computer
Anymore, if you work on carbed engines, go on amazon and order a wide band o2 sensor and gauge for like 50 bucks.. the best way to tune a carb is actually being able to see the fuel ratio out the back door. You can "Tune by ear" and get sorta close but not as close as actually seeing the AFR's Pick up a couple horsepower and/or tune for economy. Easier too. you dont need to run plug checks I've also seen the Johnson 15s make around 30hp with some intake and exhaust work. I would also like to recommend open your plug gap to .046. 6 over recommended seems to make a little better power on almost every engine. those flat plugs are complete garbage. Hell anything with more than 1 electrode is garbage.
02 sensors and carb synch tools like that are only for 4 strokes . no way are you able to get 30hp out of these without some MAJOR port, carb, exhaust and head work. even then i'm skeptical.
I don,t know if you saw my comment before - But those engine,s have a problem with the water tube grommet at the power head it petrude,s up into the block and closes off the water flow after the motor warms up and starts blowing steam. It needs to be replaced. I am a marine mechanic who originally discovered the problem it shows in salt water sooner. There is a service bulletin about the problem.
I just took off carburetor off 15 hp Johnson 1989 .waiting for carburetor kit. I noticed when I took carburetor a part, the springs came loose on side of carburetor. These two springs are connected to the linkage that the choke controls. Can you send a diagram how they are supposed to be connected?
Okay so I have been a outboard mechanic for more than 20 years and I can assure you that a 9.9 and a 15 have one specific difference and that is the intake ports that go into the cyclinders are smaller on the 9.9 and the exhaust ports are also smaller this is why the blocks have different part numbers a 9.9 is a 9.9 also the intake manifold is smaller .
The only difference between a 9.9 HP and a 15 HP motor is the carburetor and reed plate assembly. The difference between a 9.9 HP Reed Plate and a 15 HP is the thickness of the reed valves and the fingers allowed the valves to open an additional .020". My Father worked there 28 yrs, working on the 25-35 Powerheads, Father-in Law worked there 32 yrs, making the 9.9-15 Powerheads the last 20 years he worked there. I worked there 17 years also. The Long shaft just has a 5" lower unit extension with a longer shift rod, water tube and drive shaft. Chances are Edward Reifschneider(FIL) built your Powerhead, my brother Gary assembled your Starter and Transom Mount. If you have any questions contact me.
I purchased a 15 HP Johnson in 1982 in Manaus Brazil to use in upper reaches of Amazon tributaries. It was a factory modified motor based on the 10 (9.9)HP motor with the stouter lower unit from the 25hp model. It had a heavy duty low pitch propeller. The advantage was that it was light weight enough to haul it up some of those 50 ft high river banks. We mounted it in a 21ft aluminum boat and travelled 10 days for our first trip to an Indian village. We put on several thousand miles of travel with that boat and motor before it was stolen. But it was a good reliable motor - not fast, but it pushed a load of 1100 kilos easily. We often had to jump over logs, and under logs to get upstream. Thanks for bringing back a fond memory!
A 9.9 to a 15hp. One of Johnson's little secrets to keeping their product line up. My Dad worked at the Waukegan plant for 33 years. He told me this secret years ago.
We need more boat mechanics that care about their work like you do. Thx for that! 💯👍🏼
I appreciate the kind words, thank you for watching
Thank you very much for your video. I just purchased two 9.9 Johnsons (a 1975 and a 1976), and with the help of your videos I'll have no problems tearing them down and making them as new as possible! Thanks again, stay safe. Watching part 2 right away!
glad the videos helped. Thanks for watching and commenting
Stephen C Foster park near me has a 10 horse limit on boat motors so everybody used to buy 15 horse and order a 9.9 cover to conceal their deception. The Rangers wouldn't look too hard back then if you weren't causing trouble. The first 2 digits of the vin plate is usually either 9.8, 9.9, 10 or 15, and you can change the 15 to 9.8 if you're careful and smudge the whole plate a little. Just a little outlaw fun from back in the day.
I should've read more comments lol
Mines the opposite its a 9.9 with a 15 horse cover.
@@ExploringCabinsandMines Well sir That is call getting ripped off lol
@@nickalasd.1091 Well sir I got it for free soooo .....not.
Mike
I was a master tech on OMC AND Johnson/ Evinrude outboards back in the 70s thru the late 90s. You are correct on the conversion from 9.9 to 15 hp. I you check the parts manual for your model year you will find that there is a shim that is fitted under the reed plate that will allow the reeds to open a bit further which in turn allows for the extra fuel. Also the difference in carburetors is the size of the venturi.
Absolutely correct. So many folks want to argue about it, it crazy. Thanks for helping me set the record straight with some folks.
Oh! I'm so glad the algorithm suggested this. I'm about to buy my buddy's old 1960s 14' fiberglass boat with a Johnson 9.9 on the back.
Do it for sure. Thanks for watching
I like watching you better than anyone else working on low ride Johnson 15hp . Thank you so much
Much appreciated Joe, thanks for watching
Great info-Im working on my 9.9 1980 original owner was Dad. Been sitting for 8 years--
The Florida pool pump motor bearing repair guy When Service Calls Longwood approved ! that was good info RMD
Right on
Always agree, when you purchase something used, check and change oil, plugs.fluids, filters, etc so you have a starting point of your own for future maintenance.
Absolutely. Thanks for watching and commenting
That water tube grommet that you said doesn't look right is just a different style that was used on those outboards especially, to make it easier to get the copper tube guided into the grommet...it is a wide mouth grommet and will work on most any Johnson Evinrude. I use them when I can...they help prevent the grommet from folding over and obstructing flow as it is nearly impossible to see if you have the tube IN the grommet when sliding the unit up into place on some motors. Great, no nonsense, helpful video for folks doing this for the first time.
We had an Evinrude dealership in the 80's. (Roshway Sales and Service, Dryden Ontario). Same parts book and service manuals for the 9.9 & 15. I don't remember the parts book listing different carbs, but I do remember it listing different cylinder heads. (And I suddenly remember I'm gawd awful old)
I just bought my first boat, a 14 foot that came with a free 1994 9.9 Evinrude 2stroke. Guy said it had very very low hours but didn’t run. I had to fix a couple wires that were chewed from mice. The air box was packed with acorns, and the carburetor was thoroughly cooped up. I took it all apart, cleaned the carburetor,got the Jets passing air, put it all back together and it fired up on the first pull, purrs like a kitten.
My one concern, it seems to not squirt the fresh water at idle but does very well when throttled up slightly🤨 I hope it’s not a problem. I’ve only ran the motor 2 times for a few minutes so far, haven’t taken it out yet.
Your video would’ve help me a lot if I saw it before I did all the work 😂
Hi Michael.......greetings from Australia. Just inherited a 9.9 Johnson and knew nothing about it until now. Many thanks for sharing your knowledge and indeed your friendly presentation. I am confident I will now be able to repair and use it as an Auxiliary motor for my boat.
Great to hear!
When grewing up one of my neighbors at the cottage had a 9.9 hp, but in fact was a 15 hp with 9.9 badging. They are exactly the same size. He won the 10 hp and under catagory at our local Regata for years and has a shelf full of trophies to boot.
I have owned a 1982 15 hp Johnson for 20 years...the 9.9 and 15 hp motors were exactly the same. All parts were I
nterchangeable.The only difference between the two motors was the jetting in the carbs and the timing.The 15 ran at a little higher rpm
Cheating must have made him so proud of himself
@@fishhuntadventure for real! What a jerk
Back in the 80's I bought a used 15hp Evinrude and replaced the decals with 9.9 decals so I could run it on our local "below 10hp" lakes. The serial plate on the mounting bracket still said 15hp but i was never checked by the game warden......I just never opened it all the way....LOLGreat little motors.
I agree you got to play smart.
Good one!
I think if you look around Canada you will find thousands of that year or model in Evinrude and Johnson outboards. They seem to be a bullet proof little motor!
I enjoyed your presentation! Hello from Canada! Please stay safe!
Your right I,ve owned two the only reason I bought a second one is because someone stole my first one ( I am from ontariariario)
Our family have bought 10 9.9’s from 1974 and they all still run today
Knowledge Drop: 9.9 & 15hp OMC engine cowls are interchangeable as well
Just now seeing this video. My man is giving really good info. Helped me a lot to figure out an old motor. I like knowing what I am working on before working on it and seeing others break it down helps. Thanks for the video!
Glad to help
@14:10-> shaft should measure from anti ventilation plate, which is nearest to up from prop.
you are correct.
Hi. As long as I can remember the 9.9 Hp and the 15 Hp were the same engines with the 15 just boosted (sorry I was early).
In my book at first look this 88 is still a beauty .Being that old the main problem will be the rubber parts craking.
These were the last years of the best quality engines and Envinrude-Jonhson ruled the water for their no nonesense Chevy style.
Good luck
As a Master mech for Jonson I will say that you do a very good job and your Information is also very good.
Thank you.
I have a 1986 Johnson 6 hp with the original spark plugs. I have used it every year all summer.
Good day, a correction should be made about proper mounting height of the outboard. The anti-ventilation plate {the wider wing on each side of the gearcase}, should end up between flush with the center bottom of the hull and up to 1.5" inches below it. If it is mounted any lower it will act like a hook and create drag, or if mounted higher the prop will over ventilate and you may end up with less water being sucked up by the water pump. This rule may be different with boats set up for racing, but they also different or modified parts to achieve the desired result.
Thanks for the tip. Been a whole bunch of folks commenting about my mis speaking about this. Thanks for watching
Just so you know, I didn’t think you were “long winded”. You made sure we in the audience understood where you were and where you’re headed. I have a 1990 Johnson 8hp. I o all my own work as well. Thanks. Headed to Part II .
Cool, thank you for watching.
Hid the 15hp on a 9.9 only lake! Great find!! Probably on a posture boat...
You can fix that horrible crack in your floor very easily - get a roll of foam backer rod that will fit and some self-leveling caulk at your local masonry or big box lumber yard. Push the foam into the crack - can use a couple of rows on bigger cracks - and then fill with self-leveling caulk. It will sometime form a big bubble but just pop it when it does and it will level itself out. This is what we do in commercial construction jobs when we have this problem. If you want a concrete finish, then use self-leveling concrete. You can use it instead of the caulk or over the top of the caulk by leaving it down a little bit below the service, a half-inch should do.
Very informative..I really like the info on the difference between a 9.9 and 15.. thinking I'm gonna build me a sleeper for the water
Go for it!
Same Block...parts are interchangeable...I put these on more sailboats than I can remember...lol....I took a 9.9 all over the South Pacific...Half a pull and my motors start and go..Damn good motor and easy to maintain...Dont let anybody tell you different.
Walter here, on my wives page. I just found your page and will now be a regular viewer. I like and appreciate what you are doing. This kind of help is something I believe we can all gain from. Thank you for it. I recently picked up an identical 9.9 and thankfully it runs like a top! I'll soon be playing with an 85 horse and will be using info I gain here to help me.
Welcome aboard!
Thanks for these videos. I bought a little skiff a few years ago that has a 15hp Evinrude, of the same vintage as yours. I believe they are the same engine, just blue instead of white. Your videos will help me in getting it running again. Thanks again.
Up through the mid 90's a lot of local legislature made you register boats with engines 10hp and over. A 9.9 cover on a 15hp was an easy work around.
Why do I watch this? 😆 Nice channel. Now I have another subscription to go along with the guy who digs junkyards for cars to fix and the bus grease guys😃. It is all so interesting.
I've got a 91 9.9 electric start long shaft, thing runs great.. matches my 1990 60hp tiller.
The value of these old 9.9hp motors are up, pd $300 for mine.. will easily sell for double
It's because all the new stuff prices are driving up old stuff prices, thanks for watching
I also had a 15hp model and it was one of the best motors I ever owned..sold it when I sold the boat
They are reliable for sure.
I have a 9.9 evinrude outboard ,I found out that pulling the flywheel makes it easier to remove and replace thw pull starter , I like your vidoes thank you keep up thegreat work .
Thanks for the info, thank you for watching and commenting.
@@Michaelsbackyardmarina you are welcome , I would like to know where you are located please . I have miht have 2 outboards I would like to possibly trade for one good prefer at least 20 hp
@@edwardnorlander6212 I'm in eastern Iowa. What two outboards are you talking about trading in?
I have always wanted a 9.9 Johnson!!
Converting a 9.9 OMC to a 15hp but keeping the 9.9 cowl was fairly common in New Jersey where many fresh water lakes are legally limited to 10 hp. At some point the newer 9.9 motors were changed and unable to just change carb to convert to 15 hp.
you are correct, thanks for watching
short shaft / long shaft measurement"
I believe you measure from the top of the transom to the cavitation plate
You are correct
Getting dad's old 9.9 Johnson and '57 Johnson 7 1/2 he bought new like the 10hp. Mine is a 1980 maybe. I subscribed and probably will contact you when they arrive. Had them shipped from Maryland to CA. Arrives tomorrow or Tuesday hopefully. May do your upgrade to make it a 15hp. Many thanks for your video. Steve
send me an email of them running when you get them done
When you pulled the carburetor you said the screw on the cam follower was for 'idle' adjustment which is wrong. It is for "synchronizing" how far advanced the timing is when the butterfly in the carb begins to open. The idle adjustment stop should be on the outside of the motor by the throttle tower/back end of tiller mount area.
You are correct, this video is over two years old much more has been learned since then, thanks for watching
@@Michaelsbackyardmarina Yeah, but people as recently as half that have replied and who knows how many have not, but have trusted your 'mistake'? Perhaps, if possible, to pin this reply string as an addendum instead?
Since you use Snap on get a 1/4 Dr. 7/16 universal socket 6 in extension and after you remove pull start you can get the nut off the carb real easy.
You will find the 9.9 and 15HP are identical in all areas except the 9.9 carby is a detuned 15HP, they do this by adding a sleeve in the venturi tube and changing the jet sizes, kits are available for this purpose maintly aftermarket suppliers, but this is also common with the Mercury 7 and 10HP as well as afew other motors...
The older Evinrude & Johnson 9.9s had a restrictor plate at the carb mount that could be removed to make it a 15 H.P.
Understood
What years??
i have a johnson 9.9 engine short shaft, the last pull on the recoil rope on the lake recently resulted in the rope no longer recoiling, Luckily the boat engine started and i got it off the lake. Despite that i like the johnson engine.
I do like how they run
In our region ,we have hp restrictions on many lakes, often 9.9 or under.. so .. cowl off of 9.9 on 15hp usuually works ok ..unless the Conservation officer checks the motor tag..
That could certainly happen. Thanks for watching
In Washington state - where I am , there is a " 10 hp " limit on lakes , some people got decals or a 9.9 hood....on their 15s.... I bought a 1990 Evinrude 15 short shaft brand new.... I paid $1399.00 for it.... those were awesome motors.....The throttle cable broke on mine when it only had a couple hundred hours.... of course the previous years had a gear to gear throttle system.... I loved those motors though.... that 15hp rapped out to 7000 rpm.... and it woul
d run that speed nonstop for as long as you wanted....
I have one I just picked up that has a broke throttle cable. They are about $88 each
@@Michaelsbackyardmarina I recall mine cost just under $30.00 ... in mid 1991.... I probably had 200 hours on the motor at that point...in salt water / Puget Sound .... It was a bit of a chore putting it i n... the idle adjustment is part of the whole thing and was finicky the first time through....
I thought you should know - although the Comet cleanser has no abrasive, the Magic Eraser sponges DO have embedded abrasives. That's why they work so well - but they can leave fine scratches, so go easy with them.
I've got a 25 short shaft you taught me things i didn't know thanks😊
My impeller would not slide off either. The shaft was caked with old grease that had hardened. Had to use a brash brush and carb cleaner to get it off.
On these motors under power head there is a rubber grommet on copper water pipe from water pump.
Many swell closed in salt water.
Motors would overheat.
Clean around grommet and put anti corrosion grease on aluminium.
Did dozens at dealership
7.5-15 same motors.
Good motors
Hey mate can I pick your brain? I have a 15hp that I cant find anything about online. my model number is AJ15BACUD Cheers.
@@danzawraith8104 sure what's wrong?
I also bought a 9.9HP motor only to find out, much to my delight, that I had a 15HP motor. Many owners found out that taxes were higher for 15HP motors than for 9.9HP motors so cover swaps occurred. The covers were an identical fit for either motor. Cheap swap.
They also did that because some lakes have a 9.9-10 HP limit on them (15HP on the down low); they just had to hope the person inspecting the boats and motors didn't know the model year and HP are part of the SN on every OMC outboard.
I own a 9.9 Evinrude. I've never had to take the starter off to get the carb off. True, it's easier with the starter off, but it's not necessary.
I have a 15 foot aluminum boat and the only time I ever had to paddle was when I ran out of gas, (I will never, leave without a full tank again).
Even though my fishing buddy was on the other oar in my opinion that ordeal was tougher and more disagreeable than demolishing a boulder with a plastic picnic knife.
Just a heads up, when you were discussing where to measure from mounting on the boat, you referenced the wrong plate for being even with the bottom of the hull. The cavitation plate directly above the prop shaft is the plate to be even with the bottom of the boat.
Yeppers, you are correct.
Like the explanation very complete even someone like me most experience is with a paddle can understand what you are doing
the first thing you do is simply look at the model #... that will tell you the year and HP right away. for good measure, check the freeze plug on the block. takes 2 seconds. also, you keep the cavitation plate even with bottom of boat, not the upper lip of the motor.
This is absolutely true. As a collector I've owned over 200 outboards. I still have 6 of these.
@@philipdecatanzaro1822 hmmm.. Great?
@Russ Gallagher yep but that's what it's called: a cavitation plate
Mike I really enjoyed the video of you working on this motor I sent you another request of information and I hope you answer but thanks for being online I will continue watching thank you
Thanks for watching. Much appreciated
There awsome motors I had one and it always started right up 2 pull after sat all winter
they are reliable, thanks for watching
The only years that the 9.9 and 15 were identical except for the carburetor were years '74 to '76. After that the intake and exhaust manifolds were different; just changing the carb won't be a full conversion. Also, you said there was silicone under the water pump; I believe 3M-847 sealer should be applied there when you have a metal water pump. Per Evinrude's website the QL77JC4 plug should be gapped at .030, although the NGK equivalent does call for .040
It really sounds like the shop that the previous owner took it to cheated him big time.
@Russ Gallagher In 1979 they added a shim, part #325038, (one for each cylinder), behind the leaf valves and under the stop plate for the 15 hp, apparently to allow leaf valves to open up more at higher RPM, giving the motor more fuel in the air mixture.
@Russ Gallagher Yes, obvious typo. The point is that there's more to getting 50% additional hp than just a bigger carb. I've heard that the early motors were more like 13hp from the factory. And that's only at WOT, anything less than wide open and you have a 9.9 that doesn't idle well (I had a 1974 Evinrude 9.9 with the 15 carb, changed it back to 9.9).
Just seeing this now but I just replaced the plugs in my 14 hp spl and it shows the same thing as far as the gap goes... .030
I replaced fuel pump and recoil spring good gas. Still wouldn't start. Checked my gap and it was set at 28000 regapped to what you said 40000 still didn't even try to start. Went and bought new plugs Ql77jc4'. Checked gap and it was preset at 25000. Put the new plugs in and guess what ? Never ever heard it run so good. Checked online and 30000 is on the chart for this motor. Not sure what up just glad to finally getting it running. Was a nice video though.
Ove Your little shop and Love Outboards
, We use to run an 9.9hp evinrude in my youth and at that time there was a laws that you needed i liscence for run over 10hp so i eard that they actualy turned 15hp to 9.9 by caurburators exchange so the Manufacturers would have a better market.
Interesting, thanks for watching
I have a 97 suzuki 9.9 with the 15hp setup on a 12' fiberglass johnboat popular mod around here .🇨🇦✌
Very nice.
If you wet the durface beforebyou apply the Vomet and let it sit undisturbed the blesch will go to work. Im 80 and been resurecting ild machines since I was a kid.
I just may have to give that a try, thanks for watching
Back in day you could have a 15 from a 9.9 by changing the carburetor to 15 hp size. The engines in each series could lower or elevated by changing carburetors to each hp. 9.9 to 18 was one. 25 to 45?? 55 to up.
Always remember that to get the extra power the engine must rev higher, the exhaust tube and spark advance must be swapped over for the tuning to allow the additional revs. The 9.9 is actually better at lower revs and idles much better and otherwise makes the same power to 5,500 rpm - the uprated p[ower comes from the power head revving out to 7,000 rpm at WOT. Because the 9.9 is an engine rated to rev out past 7,000 rpm it is virtually unburstable at 5,500 and loves running WOT all day.
Just have to change the carb and reed valves . Same exact block and bore as a 15
9.9 is an above average Johnson. Im restoring an old 1958 Evinrude 18hp. This video was a huge help! Thanks M8!
I have a 1981 35 horse still mounted on the boat it was sold on new and it goes like a rocket!~
A 9.9 is a 9.9 because some lakes and operator ages are limited to "below 10 hp." Often a 15 has the 9.9 cover on it. And yes, a 9.9 and a 15 are usually identical engines as you explained. That is a nice little outboard.
True... Most of the 9.9's I know of are a 15hp with a smaller carburetor to restrict the power down to 9.9... Oldest trick in the book is to get a 15 carb off one with a junked bottom end.
Just to let you know - those years of Evinrude and Johnson have a problem with the water tube grommet at the power head. The problem shows sooner in salt and brackish water. What happens is the Grommet swells up into the water port at the power head and stops the flow of water from the pump. The new grommets are made a little shorter above the internal groove to stop the upwards swelling.So if your motor blows steam out of the the indicator port for the water pump now you know why. I was the first mechanic to diagnose this problem. there is a service bulletin for this problem.
I had a 25 hp Evinrude and it had steam coming out of the exhaust even though it was peeing good. Now I know what the problem is. How hard is it to get to? Can it be accessible once I pull the lower unit?
@@Dangbo3030 No you have to remove the power head then you will be able to get at the inner exhaust housing which holds the water tube and grommet to the power head. But if the tattle tail stream is peeing water steam in the exhaust is normal.
37:03 solid gem 💎 👌 thanks for making an informative and inspirational video!
Glad you enjoyed it!
Thanks for your video.
My 13yo son just bought a 1977 Johnson 15HP. It has low compression in both cylinders (65 PSI) and no spark. We are pulling it apart and trying to get it going.
Tested with a voltmeter and found good charge to power pack and nothing beyond. So ordering a new powerpack.
Next we took the head off - the head gasket looked OK but we found the thermostat was rusted. Piston rings look OK too. So not sure why compressions is so low in both cylinders.
Anyway - really enjoyed your video thanks.
Happy I found your video, I think it confirmed what I was suspecting about my 60hp of the same generation (1993). I had noticed the owners manual shows the 60hp and 70hp have the same displacement and I thought it must be pretty easy to convert the 60 to 70 if the block was the same. I wonder if anyone has done the conversion for that motor and if its the same parts to change (carburetor and reed plate spacers).
From a marine technician to you having worked in the industry for 26 years 10 of them for an OMC dealer there’s no way that’s not the original impeller and whatever parts they gave this aren’t from this motor. impeller wasn’t melted but the rubber was laid over like it been that way forever ,and the keyway was stuck.
Thanks for the info.
@@Michaelsbackyardmarina You’re welcome good work and good channel if you’re ever interested I have lots of marine parts .I started out working for an old timer who is now 89 and he specializes in old motors that large dealerships wouldn’t work on he taunted us to repair things not change parts . He was a stickler for no come backs PS I have subscribed to the channel 👍
Good too figure that out . Why won't it re-up unless it's in gear ? In the barrel of water?
It had a limiter to keep you from over revving the engine
Thanks u showed me how to take apart my bottom end off my 61 18hp Johnson that runs great I think I have a seal lacking in the gear box I've had water in it when I changed the oil and there a oil spot when I put it in the water and it doesn't like to run in low rpms in gears
Our '62 OMC Gale 15 HP is the same motor. Split the lower unit after draining. The O ring seals in your prop shaft are probably long deteriorated to nothing, replace them. OMC did not use RTV Blue when they made these in the 60's but if the motor lower unit has hit any rocks and stumps at speed, in it's life, the rubber gear case seal could be leaking also. Put RTV Blue under the seal as well a small bead on top of it to insure it's water and oil tight. Back then OMC used fiber gaskets on the gear case filler/drain screws; mid 70's changed to thicker rubber ones. Any oil resistant gasket material or rubber washer will work; add RTV Blue to insure seal and to keep the screws from coming loose from vibration. Let the RTV Blue dry 2-3 hours before refilling with gear oil, unless temps are over 80° F, 1 hour is long enough. Low speed carb adjustment needs to come out 1/4- 1/2 turn or the jet is clogged or just worn out after so many years. Try opening 1/8 turn at a time. If that doesn't help check/add/change the fuel line filter and the low speed jet.
Mike
I have a 69 Johnson 20 HP Johnson that I recently bought. It is very clean and runs like a champ in a barrel. When I put it on my boat and put it under load it kept jumping out of gear. I can't find anyone to look at it. Any ideas on what that could be. I don't feel comfortable just jumping in and trying to diagnose it, but If I had an idea of what it likely is that could give me a starting point and I kind of knew what I am getting into, I might take the plunge.
Thanks,
Paul
15 hp not only has a bigger bore carb. but also has a leaf plate shim and a tuned exhaust and that's the difference between a 9.9 and a 15. 15hp carb. part # 391654, 15 hp leaf plate shim part #325038, 15 hp exhaust tube part # 325333
Very interesting video. I will enjoy all of your future presentations.
Glad to hear that!
Thank you Mike really enjoyed it and learned a lot
Good video, very helpful and informative on John 9.9 Hp engines. Just one thing you are incorrect in where you are measuring the length of the shaft. The measurement starts from the cavitation plate directly above the propellor, from what I see you are measuring from the lower fin above the cavitation plate. Using your measurement will put the caviation plate about 3-4'' below the bottom of the boat and affect the planing characteristics & steering of the boat. The cavitiation plate should ideally be flush with the bottom of the boat but no more than a 1/2" variation up or down.
yep, thanks for watching. know all about the measurement, have a good holiday.
As for the rubber pull handle, depending on the model year, some used a 3/16" - 1/4" flat washer just under the knot others used a small galvanized steel plate with a hole (about .3" x 1") under the knot to prevent the starter rope from pulling thru depending on the rope size/ motor HP.
i use a stainless washer on every pull start I own.
You get my thumbs up for using a pry bar instead of a screwdriver!
Mike could you do a video of a Justin top idle screw inside on the carburetor and also the outside in front and also the side adjustment on the motor
I will be doing a video of putting it back together.
A good 2 Cycle Outboard tool kit should have: 1/4" -3/8" Flat Tip screwdriver, Combination Pliers, Spark plug Wrench, Electrial tape, 1-2 Prop shaft cotter pins, 1-2 prop shaft Shear Pins, 2 Spark Plugs, 2-4 zip ties. As I remember correctly, the model year is the first or last 2 numbers of the SN; note that both Evinrude, Johnson and Gale was made by OMC and almost all parts are interchangeble. Note the Data plates are the same shape, size and location with the name being the only difference. As I worked in the assembly plant and as a Crankshaft Grinder later I know a lot 1.1 to 70 HP OMC outboards. We have a 1923 1.1 HP Elto-Evinrude that still runs great after replacing the plug wire and coil in '88.
Shaft length is measured from where the clamp meets the transom to the bottom of the anticavatation plate just above the prop, not where you showed it.
You are correct.
Anti cativaton plate
@Russ Gallagher oops I got it backwards it's the anti ventilation plate
So it’s ok to pull the shaft all they way out and get the impeller off and just put it back in,right.?
Best video instruction out there... well done and I just suscribed. Knowledge tips are excellent too.
Awesome, thank you!
A 9.9 is the same size / weight and displacement. Only difference is carby and kw magneto pushes out. According to brochures on evinrude and Johnson. The cavitation plate needs to be about an inch below the keel actually.
it depends on the year, but most of the differences are bigger exhaust tuner, reeds and carb.
I have a 9.9 Johnson 1984. I purchased this motor brand new and as such have had it it's entire life. Believe me go back to the Champion plugs. Mine still runs as good as new.
That’s really awesome!!! Maybe this year I have two Johnson’s I will be working on...my first experiences with boat motors. I had no idea about the change from long to short shaft.
You can do it!
I wish it was as simple as that nowadays... I have a 15hp 4 stroke Suzuki. Identical to the 20hp except they put a restrictor plate behind the intake, and the timing is different. Only way to step it up is to change the computer
I have found strait bleach works very well out of a spray bottle for cleaning my 1974 Johnson Seahorse 7and one-half HP. when it gets really dirty.
I should have said the outside of the motor, only the white painted part
I will give that a try.
I'm learning a lot from you ,thanks for all videos
Anymore, if you work on carbed engines, go on amazon and order a wide band o2 sensor and gauge for like 50 bucks.. the best way to tune a carb is actually being able to see the fuel ratio out the back door.
You can "Tune by ear" and get sorta close but not as close as actually seeing the AFR's
Pick up a couple horsepower and/or tune for economy.
Easier too. you dont need to run plug checks
I've also seen the Johnson 15s make around 30hp with some intake and exhaust work.
I would also like to recommend open your plug gap to .046. 6 over recommended seems to make a little better power on almost every engine.
those flat plugs are complete garbage. Hell anything with more than 1 electrode is garbage.
02 sensors and carb synch tools like that are only for 4 strokes . no way are you able to get 30hp out of these without some MAJOR port, carb, exhaust and head work. even then i'm skeptical.
30mph on a Gheenoe.
You can have a "skeg" that looks like a "scag", but not vice-versa. Just saying...keep up the fine work!
For sure and will do.
I don,t know if you saw my comment before - But those engine,s have a problem with the water tube grommet at the power head it petrude,s up into the block and closes off the water flow after the motor warms up and starts blowing steam. It needs to be replaced. I am a marine mechanic who originally discovered the problem it shows in salt water sooner. There is a service bulletin about the problem.
Yes I did see your note. Thanks for watching and commenting
I just took off carburetor off 15 hp Johnson 1989 .waiting for carburetor kit. I noticed when I took carburetor a part, the springs came loose on side of carburetor. These two springs are connected to the linkage that the choke controls. Can you send a diagram how they are supposed to be connected?
I don't have a diagram but at 34:36 in this video you can almost see the choke spring on the carb.
Okay so I have been a outboard mechanic for more than 20 years and I can assure you that a 9.9 and a 15 have one specific difference and that is the intake ports that go into the cyclinders are smaller on the 9.9 and the exhaust ports are also smaller this is why the blocks have different part numbers a 9.9 is a 9.9 also the intake manifold is smaller .
Not on 1974 thru 1978
The only difference between a 9.9 HP and a 15 HP motor is the carburetor and reed plate assembly. The difference between a 9.9 HP Reed Plate and a 15 HP is the thickness of the reed valves and the fingers allowed the valves to open an additional .020". My Father worked there 28 yrs, working on the 25-35 Powerheads, Father-in Law worked there 32 yrs, making the 9.9-15 Powerheads the last 20 years he worked there. I worked there 17 years also. The Long shaft just has a 5" lower unit extension with a longer shift rod, water tube and drive shaft. Chances are Edward Reifschneider(FIL) built your Powerhead, my brother Gary assembled your Starter and Transom Mount. If you have any questions contact me.