Pressure testing an outboard gearbox
HTML-код
- Опубликовано: 26 авг 2017
- In this video I put together a simple tool for pressure testing outboard gear boxes. This is done to test the lower unit seals around the prop shaft, drive shaft and gear selector.
Parts used are:
www.ebay.com.au/itm/142414466394
and
www.marineengine.com/products/...
For outboard repair information, checkout my website: outboard.dangarmarine.com/guide
If you are enjoying this channel, please consider making a donation to www.paypal.me/dangarstu or become a Patreon of Dangar Marine at / dangarmarine
T-shirts and other merchandise available at teespring.com/stores/dangar-m...
Common items used in these videos are available from my Amazon store at www.amazon.com/shop/dangarmarine
Dangar Marine is proudly sponsored by MarineEngine.com. MarineEngine.com supplies a wide variety of spare parts for many brands of outboard motors. If you are in the US, be sure to check out their online store www.marineengine.com/
All music available at soundscloud.com/dangarstu
I just finished successfully pressure testing my outboard lower unit after finding out I had some bad seals. I could not have done it without this channel. Your explanation of the different systems and showing different ways of doing things gave me the confidence to tackle this job even though I don't have the exact right tools for it. Thank you!
Thanks Chris, glad you hear you got your lower unit fixed up. :)
Great tip and very timely! I recently bought a project boat with a 1975 850 Mercury. It hasn't been in the water in five years according to the registration sticker. A cracked bearing carrier assembly with the reverse gear, dog, shaft, and prop were all attached and lying in the hull. Got a used lower drive unit today and was wondering how I was going to check the seals before installing it. Now I know!
Thank you; DM, & Marine Engine. I haven't seen all your videos yet but I'm working on it. I learned a lot on this video. I already own a vacuum tester with some attachments. Thank you for all your demonstrations of repairing outboards. Keep up the good work my Friend !!!.
Thanks mate. Glad you enjoyed. :)
Great video Stu. Home made tools can be real money savers. I've made tools out of plumbing parts, spare parts and junk pile parts. And I have I don't know how many "custom" open end wrenches made by cutting up flea market wrenches and welding them together at whatever angle got me into the place I needed to be. Whatever I needed to do to get the job done! When you don't have, you improvise!
Thanks Jack, bent, ground flat and welded wrenches certainly are something you collect over the years for those hard to reach places!
I also like the right amount of dry humor in the video's. Keep it up
Thanks for all your videos if it wasn't for you i might not have rebuilt my lower unit. With your videos my confidence level went way up thanks again, Jim
You're welcome James, glad the videos helped you. :)
Thanks for showing this. Works great. Love the calendar girl over your shoulder. Can't wait for next month.
Good vid. I learn something new everytime I watch one. Thanks for making them.
You're welcome. :)
Excellent and practical techniques demonstrated. Thanks a lot, really useful demo
Wonderful as always, Stu !
That was great Mate, taking advice and getting one of those brakes hand pumps to test lower units. Have an awesome day Mate thanks Robert
This video was exactly what I was looking for. Trying to pressure test my lower unit in an affordable way. Legend, thanks!
Another Sunday, another great vid
Thanks mate! And thanks for helping others out in the comments. :)
Thanks for helping me rebuild this motor Dangar Marine 💯
Absolute legend Stu, your videos are always inspiring and very helpful and educational!
Thanks mate!
Have a look at your inbox mate sent you a message about a new video idea!
Thanks again Stu, another useful vid...you're making sunday arvos almost bearable!
Thanks mate. Sunday afternoons are hard work. ;)
Thanks for this! Managed to pressure test and find the leak in my dad's gearbox today and get it fixed 👍
Nice work! Glad the video helped you. :)
Great video mate. I already have the oil fill pump and hose adaptors, and will get me the brake bleeder/pump on my next trip to the auto parts store!
Cheers for another good vid danger stu! Be good to see the next!
Thanks mate. :)
damm! I just notice my gearbox oil pump exactly same as yours and I think "I could do something more about it with a bicycle pump plus pressure gauges...." when I replaced my prop shaft oil seal early today, and now I open this video.
Thanks stu! Really love your video about very useful tips!
Thanks Jerry. Great minds think alike! ;)
Thanks. Will be making one of these to test my work on re-sealing my mercury and johnson outboards.
Thanks for the time and effort you've invested in the videos! The videos are absolutely brilliant - they have made me start "wrenching2 on my Tohatsu with a whole other confidence level. Well done and please keep 'em coming.
If i'd had a say on future content, I'd really like to learn more about temperatures and potential overheating; how to look for signs before it's too late? and also whether a carved two stroke is running lean or rich; how to diagnose etc. Just
Thanks mate, glad the vids have helped you. I like your suggestions, I'll add them to the list. :)
Another good one! I'm turning in to a pretty good DIY with your help. First was a steering cable with your help. Now water pump impeller is done. On to propeller shaft oil seals. I have to admit that I watch others but even though you have a accent, Ha! your able to explain things well, so that I understand, well. Which can be a challenge sometimes on my part. Keep up the good work mate! The old 84 75horse Evinrude is still fishing in Oklahoma!
Thanks mate, glad to hear your are getting good at your DIY. :)
Great video Stu, My son's 110 9.8 merc lower unit was leaking and got the tool to remove the prop shaft unit nut. Pulled it apart and replaced all the seals and orings. Also replaced the cracked impeller housing. When done didn't know about this set up so just put pressure using the lube pump to see if the leaks stop and all is good. Next time we change the lube will pressure test it with this method. Oh and took the tool back to get our money back😎
Thanks Tim, interesting idea about using the oil pump itself to put a bit of extra pressure in and look for leaks.
Thank you sir for the tutorial. Knowledge is power. Even if I don’t do it myself I’ll be wise enough to know if the person I hire is not to handle the job.
You're welcome mate, glad you like the vids. :)
Another great vid , thanks as always !
Great video thank you for all your help on boats , watch most of your clips now very helpfull i am in cornwall uk boat off falmouth .
Thanks Guy, glad you've been enjoying the vids. :)
and as always thank you for the videos that you make they are very helpful
Another thing I do all the time at work. We use the Stevens Instruments pressure and vacuum testers.
Interesting, they look really good and aren't that much more expensive than making one up like this. My prices where Australian dollars though so they might be about an extra 50% I guess. Thanks for pointing them out.
Useful video, thanks! definitely one to add to my toolbox
you're an absolute legend, it would be cool if you could do a video on what to look out for when considering buying/using/fixing an older boat, I've possibly got a small boat that hasn't been used for 20 years or so and it would be cool to know what sort of things to look out for to consider if it's worth trying to get running.
Thanks mate. I've actually got a video on that exact subject half finished from when Paul bought a new bought. I'll have to finish it off soon.
awesome! looking forward to it!
Just bought my first boat with an '82 Merc 18hp with issues so I'm learning fast from Dangar Stu, the others, not so much. I have a good quality bike pump with pressure guage that I think I can attach the pump to so I've just ordered it. Unfortunately I'm in WA so who knows when it will get here, sometimes I think even the '70's haven't shown up yet.
Great video. Can't help but notice your calendar. Lol
Thanks I will be putting my own together
Stu From your idea I bought a Schroder valve with a thread, attached that to the oil pump hose like you did, bought a cheap bike pump with a gauge and presto....I had reservations on gauge accuracy so tested against a good one and she’s apples. Thanks bud.
Nice one, a bike pump that already has a gauge attached is a great way to go. :)
AWESOME convergence of thinking on this!
Ha ha...the very same thing just occurred to me, just before I saw your comment..."great minds think alike". Cheers.
Great video. I now feel confident I can find the source of my leak. Not sure if I can fix, lol, but at least find the leak. Next question is how hard is it to remove and reinstall the lower unit?
My gear oil is just a little bit milky. It was clear until the last bit drained out. Pressure test held at 10PSI for 1 minute until I took it out. Should I worry about it? And thank you for the education, I’m going through a 1999 Honda BF90a and you’ve been a life saver.
awsome info as always Stu , i need a tester like that one that you show , i mess with alot of seadoo;s and outboards the pop off pressure on the carbs always a problem for me without the tool , cheers m8
Thanks Randy, I really recommend grabbing one of these.
thanks for the help, keep up the good videos
Glad to help. :)
Stu, please do another update to this important video showing testing the little red oil washer between the upper and lower unit. Show how to torque all the bolts, especially the side ones (spanner only, no socket). Thanks.
these brake bleeder pumps (similar)are now about $22 australian, might buy one
A brilliant re-purposing of tools. Obviously a man with a few more brain cells than the average bloke. You are simply more proof that thinking is a skill far superior to sheer brawn (although sometimes, that, too, is nice to have...). You guys have good taste in decorative skills too. p.s. Don't worry about running what you seem to be deeming a "filler" episode because another episode has fallen into production difficulties. I don't believe you have a published schedule to adhere to. Can't speak for all your viewers, but since I've been following you, I have yet to have seen a "dud" episode thus far. Sure did enjoy following the 150 Evi saga, though. Cheers from Ontario, Canada.
Thanks Stan. Although it was a last minute filler, I had been wanting to show the new tester for a while. I also have it in my mind that I would like to replace some of the older videos that weren't very well recorded (lots of umms and bad audio etc) Hope the repetition doesn't bore the long-time viewers too much. Thanks for watching! :)
Adding a shin basher to the lower unit stand sounds like a great idea to hold your oil pan. :-)
LOL. The revision after that will have padding!
Thanks for this video I have all the bits to put one together, I look forward to your video on the tilt trim on the Mercury, mine is a electric tilt trim quite complicated but I managed to get it put back together but I'm still puzzled by the throttle only button it stays in and somehow I think it should be spring loaded but I saw no spring when I took it apart and the manual doesn't show one either, it's a Mercury model 327 shift lever
Yes, I would imagine that button to be spring loaded and pop out when the motor returns to neutral. Perhaps the mechanism that releases is in neutral has failed?
I agree and I put a call into Mercury in Wisconsin, spent half an hour with someone who tried to help but couldn't but he told me he would get back to me with an answer, the schematics didn't show a spring and my local Mercury dealer hasn't been able to figure it out yet, I'll give you an update on how this all goes
Love your videos. They give me good ideas for maintaining my Yamaha SX150. I have a Mighty Mike brake vacuum hand pump but it only pulls vacuum. Do you think pulling a 10# vacuum would be just as effective a test as pressurizing the gear case?
I certainly think it would give you a good indication if a seal has completely failed, for sure.
This video is spot on ! Thank`s !
Glad you liked it!
Great video Stu ! When you have the time maybe you could show how to check and replace bad rubber mounts ? Both the lower and underneath the motor. Take care m8
I'll add that to the list as something to do in a video on its own, but from memory this old (and probably very badly made) video does cover that as I replaced the whole midsection on my original Yamaha when I was rebuilding it. ruclips.net/video/GV-Gd9il9MA/видео.html
Why does my 1971 merc 400 have a "flush" set screw that goes through into the impeller housing.. what's it for does it effect pressure testing. I ordered the pump you've recommended to try this next week when it gets here..
Ah that's funny: the USA version of that gear lube pump comes with the opposite aka a metal plug adapter for nissan/tohatsu. i hope the plastic end actually seals the lower unit since i don't have a metal one for my Evinrude. Any ideas?
Excellent Video, but I have a question...I have this same hand pump, but it creates suction, not pressure. Is that what you're doing? Testing with suction? I can see that it would certainly show that the lower unit is sealed, but how would it help to identify leaks? If you spray soapy water on the seals, you will not see any bubbles, therefore could not find the bad seals. Am I missing something? Love your videos, I truly appreciate all of your knowledge and your sharing it with us. Extremely helpful..!! Thanks...
This one does suction and pressure by moving the black collar at the tip forwards and backwards. I also use pressure as you say so that you can spray water and find the leaks.
Tip - I did this and the pressure dropped quickly. I mixed up a bubble solution and found the device was leaking where the clear tube fits onto the plastic barb. I put some gasket liquid sealer on the barbed plastic bit and some grease on the plastic thread and found my gearbox was holding pressure perfectly. I was very releived because I had already done the water pump and didn't feel like undoing it to fix the seals under it.
Hi I was changing the gear box oil on my mariner 5 and what came out looked like water first and then dirty oil. I’d like to try the pressure test to check which seal may be leaking but do I need to remove the water pump and lower leg etc: I was hoping before I have to take the engine apart further I can check if there is an actual leak or maybe the drain plugs were not tightened enough ( wishful thinking maybe !)
Thanks for the great channel and advice; helped me attempt servicing my outboard
John
Thanks. I comment, my tech did the annual maintenance on my 2006 mercury optimax 115 two stroke. After that, I have notice an oil leak with water through the water intake holes. He fixed changing the seal of the transmission. Everything looks fine until this weekend that I have the same leak again. I would Iike to know your opinion. Thanks
you da man as usual. Thx M8
Ripper stu.A note for followers, I filled a bf150 gearbox with a small bottle pump recently and just ran in vent screw a few turns to really fill it and squirt a little head room out. I gave it a half pump to make sure it was full, and it leaked oil out of prop shaft seal. Pressure tested box and it held 10psi indefinitely.So lesson is you can Put quite a bit of pressure in hydraulically, as opposed to air. Don't fill with vent screw even just threaded. Bad news.Cheers
Hi Matt. Interesting to hear that, I wonder how much pressure that oil was creating with only half a pump? Thanks for sharing!
Awesome video cheers
Great video as allwase . QUICK QUESTION I HAVE Honda outboard bf15D impe changer the lower unit gearbox oil a little water in it have you ever done a video on diy pressure tester with a bike pump
Yes, very old video though so quality will be poor ruclips.net/video/Lzn-nshSlwk/видео.html
Great video, thank you. I have a gearbox that had water in it. I did this test, and found no leaks, I have put it down to a missing nylon washer on the fill screw. I can detect no play in the prop shaft. It shifts gear ok. The magnetic bung had no unusual debris on it. I dont know if I should tear it down or not. My worry guts side says pull it to bits, but that will be a very tricky job, it will be very siezed. My lazy side says fill it with oil, check the magnets for debris in an hour or so. What say you ? TIA
That's what I would do. Last year I bought a o ring kit from. Napa so I could change them everytime
I like your video's....good job
Dangar Marine, can you tell me the way oil seals go up into the water pump housing. Maybe I have the seals wrong therefore leaving not covering the hole...
Hey stu thanks for helping me rebuild my 1958 evinrude lark with your videos, how do you replace the O ring that seals the gear shafts to the lower unit
I've made a play list for lower unit videos now. I have one in there were I change that o-ring on the Evinrude I did ruclips.net/p/PLJD0gZGZdCucJFYEoe-I93VANNzgTgPkV
Dangar Marine thanks alot again for the help
Great vid as usual!!!. I commented a while ago about starting my 150 hp. black max that is on a stand. Can you please tell me how i connect the battery cables on his engine to start it . The max had no cables on it when i bought it .I have the controls for the engine. Thank you sir .
Hi Tom, the positive will go to the starter solenoid, the negative will go to the engine block. This video may help ruclips.net/video/Vt8aRamdac4/видео.html
Hi Stu! Great videos and long-time watcher of the channel. You have been a great help on my outboard adventures. I pressure tested my lower unit (2007 115 Mercury EFI) and did not see any bubbles at the seals but heard a leak from inside the water intake. Any ideas what it could be?
Did the pressure drop? If so it sounds like it could be the driveshaft seal which is under the water pump.
@@DangarMarine the pressure never got above 5psi
@@DangarMarine you are a gentleman and a scholar!
This is great thank you. Just made mine for £25 - bargain! I've just changed the dog clutch in a Honda 10 and need to replace the reverse gear. I'm new to this - how do I get the damaged gear out and put the new one in? Any help much appreciated.
The reverse gear you will need to get off the bearing carrier using a bearing separator like this: www.ebay.com.au/itm/like/172102345794
Hi Stu, I have a question that may be related to the gearbox. I bought a 96' 100hp Mariner that is making a screech ever time it goes into gear ( and it's not a clunking or grinding sound). The motor has not run in three years so I want say it may be a dry seal? Any thoughts on what may be going on? PS- the shifting mechanism is not like the Johnson or Evinrude where it goes up and down but rotates.
Regards, Dan
Thanks. I just realized that my bike pump (and many others) have a built in pressure gauge...the plastic gear lube pump just needs to go the bike pump...Viola! In the last video you invented a bike pump with a pressure guage :-) Cheers.
I just checked...the top of a bike presta valve on a 20" bike tire screws right into my Evinrude gearbox!
Not sure how to connect the pressure valve bike pump to the bottom of the Presta valve...Schraeder is close...managed to pump about 1psi to gearbox this way...maybe enough to spot extrusion on the seals...need better connection to Presta valve...
I would make up a short hose with an Evinrude thread at one end and a Presta valve at the other end.
hello, I have merc 25 1997 3 cylinder. I did the test on a cold and on everyone I have about 120psi. Is there more heat coming out? I can't find anywhere for this model how many should it be? Is this good, medium or poor? Regards!
Is it best to test your lower with oil or drain it I drain it and look over the old for Metal shavings and what not if there’s no water in it thanks for the info
If the lower unit does not get vacuum or pressurize when running and the oil level is well below the top seals. Also with the top seals being shielded from weather and water being above waterline and below motor, would it matter at all if the top seals did have a leak when pressure testing? I guess condensation would play a bigger factor if they did have a slight air leak but not enough to make a difference if regularly change oils right?? Just wondering what harm it would do to not worry about the top seals leaking a little if at all. As long as they are keeping dirt and bigger debris out than thats all theyre really there for i would think..
Great vid, Stu - I've heard techs talk about pressure testing a lower unit but didn't really get how it worked. Have you covered how to replace each of the seals you pointed out? That would be a great companion set to this one.
I do have a few videos on that, and you've made me realise that I probably have enough videos to start grouping them into playlists. I'll create a "Gearbox" one now which will help you find the relevant videos.
Here it is ruclips.net/p/PLJD0gZGZdCucJFYEoe-I93VANNzgTgPkV
Nice - thanks again!
the lower unit oil pumps are readily available for around 6 bucks at most boating supply stores...for a slightly cheaper option
Is a pressure tester required? I have a vacuum tester with a gauge that only displays negative pressures, from 0 to -30 inHg, I would assume because it only vacuums and doesn't actually push air in. Yours displays both (negative) vacuum and (positive) pressure units. Is a pressure capable unit required?
Thanks in advance.
That looks like a standard torsional overload fracture surface on the drive shaft. The fracture surface is beat up from contact after the fact but I don't see any obvious ratchet markets indicating a fatigue failure.
In other words they hit something.
It certainly looks that way, but I'm surprised the prop wasn't in worse condition.
I just did this pressure test on my 1974 Johnson 2-stroke. I found some water in my oil, however the test held 10psi compression very well. It didn’t move a notch until I let pressure out. What could have caused the water to get in? Possibly loose oil plug screw?
I'm Ronaldo Pires from RP Náutica, I watch your videos and I like a lot, but it's a shame that it's not subtitled in Portuguese, congratulations my friend
Thanks Ronaldo. I have activated community contributions so anybody who speaks both languages is able to add subtitles.
Hi Stu, how about doing a outboard motor in a test tank with a test prop. Just showing how to check timing and carbs on a 2 stroke. 50 to 70hp engine that is best left on the boat. I have been looking but nobody has done a video on this.
A video you'll probably see before that is building a test tank given I currently don't have one!
Ok will build one someday and do a video. I don't see one by anyone else so would be a good one to do.
Is there a multimeter with tachometer specifically for boats? I have a multimeter/tachometer for automotive with 3, 4, 6, 8 cylinder settings. Boat motor only has 2 cylinders. What do you use?
Hey Stu, and everyone else for that matter, would it work to do this test with oil still in the lower unit? It seems that doing so would allow you to see any leaks but I also wonder if that may cause a seal to fail and is the reason you drain first.
Hi Darin. You need to drain it first so the air can get to the seals as the oil isn't compressible. There will be an airspace above the oil so the test may still push oil out the seal and allow you to spot a leak, but I think it would be tricky, and you really need the gearbox off to see the top two seals anyway.
you can get one of those gear oil pumps at walmart for about $6-USA dollars
Thanks bro
Welcome. 😊
bought the pump and tested my merc 90 . factory says 10 psi for 5 mins, no drop at all . thanks one less thing to think about
Sounds like it's good to go!
I bought all the parts you mentioned but I have a question about the pump. The instructions say that you put the slider to the rear (towards the handle) for vacuum and forwards (away from the handle) for pressure. It seems like the instructions are backwards. Can you let me know how yours works? Thanks
Hi Stu,hope you don't mind me asking,I have 1999 Johnson that I have put a new inline sight glass fuel filter on.
The site glass nearly empties when the engine is running,but has more in it when it is ticking over,is it normal?
The engine runs smooth,and is quick to respond to the throttle.
Yes, that is quite common.
I am currently having an issue with my gear case. It passes the pressure test with flying colors. It actually holds 15psi indefinitely. Yet when I take the boat out and check the fluid when I return it looks like milk! Did you ever experience holding pressure yet water still getting in. I suppose I need to vacuum test at this point but it seems odd that it would leak when it holds pressure.
Hi Stu, this but be a stupid question, I have a 1986 Johnson 70HP outboard. Does this motor have an extra gear between the forward and neutral gear, sort of a neutral forward gear?
Can't say I've ever heard of an outboard having that. If the prop is turning while it is in neutral it is just the friction of the oil circulating causing that.
I bought a vacuum pump/brake bleeder but it doesn’t appear to have an option to pump air instead of vaccuming it. So I’m assuming that’s not going to pressure test my lower unit?
Motor stopped working after pressure test what is the reason stopped? Normally can turn the motor shaft by hand but after pressure test the shaft is no moment at all, what is the main cause. Thanks
My oil seals went bad on my 150 hp Johnson, now with the water intrusion I need to replace the needle bearings. Any tips for how to remove those bearings? The forward needle bearing on the carrier has two cutouts that I can get a punch in to punch the bearing out, but the rear needle bearing doesn't have this so there is barely any lip to punch it out. Thanks!
Can't say I've ever done the bearings on a Johnson like that. Normally I use a bearing separator to press the bearings off the carrier and then a puller like a spigot puller to get the race out from inside the gearbox. These are cone bearings though so it is likely to be different than your situation.
do you have a link for the pressure pump? I have a vacuum pump for bleeding brakes and a pressure pump is next on my list after a leakdown tester.
Links for both parts are in the description.
I’ve used this exact pressure tool to find that my shift shaft boot seal leaked . I replaced this seal and did the pressure test and held 10 lbs. for more than a minute. I re installed the lower unit, and ran it . Then I noticed after shutting off , gear oil coming out of the weeping hole . Very little oil but still oil leaking . The pressure tool handle broke so I can’t leak test it again till I order a new one . I have a 2000 , 30 Yamaha 2 stroke . I have also installed new upper shaft seals , water pump housing, impeller, gaskets.
I’m lost for words what is wrong 😑. Did I miss something?
did this test and passed. But still get water intrusion. I heard that spinning the prop by hand while doing this test will give you a better result. Whats your thoughts on that?
Hi great video, I do have a quest, when I pressurize my gearbox it does maintain pressure, but when I wiggle the spline, the air releases, the spline is by no means loose, its just if I try to move it sideways Whats your thoughts on that.
Could either be that the bearings need replacing or the oil seal is getting a bit too soft.
Thank you, I did replace the seals last November, So I was afraid that it could be the bearings. So pretty much there should be no movement at all in that shaft?
what would be wrong or not affective to test if my lower unit is leaking by just using the vacuum? i’ve got a break bleeder but it only creates a vacuum and not positive pressure.
It should be fine. If you have a leak it will just be a bit harder to find as you won't get bubbles coming out when you spray soapy water on the seals.
Is the reason you pressure test instead of vacuum because of the way the seals are made? We vacuum test chain saw engines for the same reason. Thanks for another excellent teaching lesson!
Hey John, the short answer is that the service manual specifies a pressure test, but now I think about it as the oil heats up pressure does build up inside the gearbox (if you open the drain plug of a hot gearbox it will shoot everywhere) so I guess containing pressure is the main job of the seals.
I'll buy that...thanks!
Bot sure if it is the reason , but many seals have a 'lip' that is curled - so in use the pressurised side applies pressure to the lip to make the seal work better . As the gearbox will normally raise pressure by heat expanding the air in the gearbox I am assuming this is reason the OEM states to use a pressure test. A vacuum test may apply pressure in the wrong direction so give a false reading.
I replaced the seals then filled it with oil THEN decided I should have done a pressure test. Can I just leave the oil in it test it from the upper hole??
I would drain it first.
My tester looses 1-2 psi a sec but when I put the lower unit in water it doesn’t loose any ???
I'd like to try this with a bike pump but am afraid of pumping too much pressure. Can I blow a seal if I pump too much?
10psi is plenty.
Hey Stu, I'm a new subscriber. GREAT CHANNEL!!! I have a 1983 Merc 2 stroke and have gear oil dripping out of the prop area. I did a pressure test and it held 14 lbs for like 5 mins. Any idea where the oil would be leaking from? Thanks in advance.
Hi mate. It is going to be either the prop shaft oil seal or the drive shaft seal allowing oil to be picked up by the water pump then back out through the exhaust.
Thanks for the response Stu. If I don't see any noticeable water in the oil other then looking dark, would you lean towards one or the other?
Sometimes u can have such a small leak as in the gasket on the fill or vent screw and when not running it won’t leak but when u start the prop turning it creates a high pressure compared to outside. That can cause u to loose oil and not see it and hardly make any water at all. It’s odd bud have seen it. I believe that’s what’s happening to people’s magic oil disappearing with no water in unit. My 2 cents just a theory.
That's to much money for me!can I have yours?lol thanks for the info love your videos keep them coming
I'll lease it to you. ;)
Do you know the thread size for the american outboards? Im hoping to get the tube and screw separatley rather than buying the whole oil pump kit. Also any idea what the screw fitting would be called by itself? Not sure if it matters but i have an evinrude etec 115hp. Thankyou
They are 3/8 - 16 I believe.
Oh, and a "tail" is a threaded section with a barbed end for a hose.