Bom dia sou do Brasil, tenho um desse motor e ele acontece de morrer igual no inicio do seu teste e a pera esvaziar o combustível também isso e normal ou tem alguma regulagem para não esvaziar a linha de combustível e morrer obrigado pela atenção.
The carburetor is very similar to this: ruclips.net/video/P_pIsOZ9FFI/видео.html The fuel pump problems are in this videos: ruclips.net/video/2Km5CdTYSiY/видео.html - 2 - ruclips.net/video/WNvlLv9Ass8/видео.html - The ignition problems are in this video: ruclips.net/video/VeJIS_-xZqM/видео.html - I hope all of this can help you!
Hey I have a Johnson 7.5 looks very similar I was wondering if you could show the safety pin system ( to keep the motor upright) because I can’t seem to get it working
The flywheel key snapped on mine and sent the throttle came through the side of cowling and I've been having trouble getting the timing back in order won't Rev out all the way now
Nice work so I do have a question... I picked up this same motor and have it running but the compression seems low to me... I did the test but didn't twist the throttle and got somewhere around 50 to 60 psi on each cylinder... Is it worth going through the powerhead to get compression up or just run it the way it is?
You have to twist the throttle to open the carburetor drosel. If you don't do it you will get wrong results. 50 to 60 psi is very low compression. Rebuilding the engine is expensive. Motors with low compression go for parts.
@@BoatMotors I have a Johnson 7.5 outboard. I tested the coils and it seemed to have low resistance, I replaced the spark plug wires, new plugs, cleaned the carb. It doesn't have a high-speed adjustment screw. It doesn't seem to run at WOT. It fires up and under load it misfires and the spark plugs get black and smokey. I try to run about a 50/1 mix. I get maybe 5mph on my bass tender 9.4 It is a long shaft so it does sit further down in the water than I like but I'm not sure how to get it to run leaner.
@@FishHeadsIV Make sure you do a compression test. Follow the link at the end of the conversation, I know your motor is different, but you'll get the idea. Make sure you have a good spark in both cylinders. I hope you have the original carburetor and jet. Make sure the idle needle is adjusted well. If it is widely open it will pour extra fuel and the air fuel mixture is going to be very rich and the motor can not increase the RPM because it's flooding. That's why you have black and smokey spark plugs. I wish you good luck! ruclips.net/video/LFdQrt82Z8c/видео.html
I have the same motor. I changed water pump. When motor is cold the water is runing after few minuts water is not runing. Do You know what can I do?what is wrong? The kolumn is very dirty like mix oil with water. The oil in down part is good without water.
Watch this video and you can see how to check and modified the cooling system. Usually the nozzle of the cooling system clogs. Most of the fishermen have a paper clip and unclog it from time to time. In most cases this is the problem. Some time the old impeller can lose some of the fins and they can clogged the cooling system. Some of the old owners probably had this problem back in the time and decided to sell this outboard motor. ruclips.net/video/lnFySjQXqlg/видео.htmlsi=9K_IBxjnfV_K9_GE
Hey there, thanks for the video. I bought a 1985 8hp Johnson from a buddy of mine and I can only get up to about 6.5 to 7 mph . I know I should be getting up to about 15 mph top speed with this motor. It's on a very light weight 12' aluminum boat. I'm about to rebuild the carb, fuel pump and install a new impeller. I put new plugs in it but I'm still wondering if I'm getting enough compression in both cylinders. The plate on the lower unit is about 3" lower than the bottom of my transom just fyi. any thoughts that may help me?
Hi, you have a very interesting situation! First - make sure you have good compression. Second - make sure you have a spark on both cylinders. Third - there is nothing wrong to clean, rebuild the carburetor and get a new impeller. Forth - make sure when you turn the throttle handle the magneto plate is moving all the way the retainer link (part #0395883) and it is completely engaging the roller, cam follower (# 0323328). Make sure the cam follower (#0323327) is not broken or cracked. I'm pretty sure your throttle is not completely opened and your motor can't receive enough fuel air mixture. Fifth - I'm sure that is not your problem, but make sure you have a fresh gas and oil mixture. Good luck and let me know if you got any results.
@@BoatMotors Great thanks man!I’m pretty sure it’s the throttle mechanism I ordered a new cam follower, spring and clip because the one on there was broken I rig something up to work but I don’t think it’s working well enough. Also I did rebuild my carburetor and fuel pump I have a good gas a new tank and bulb so I don’t think it’s that. Although I don’t know but it’s a chance that the line is too big is 3/8”??
I had the oring break, that holds the cam roller onto its shaft (1.41 of this video). This will cause a massive loss of power, as the butterfly in the carb will not be able to open fully. Also, there is a foam oring where the black airbox connects to the front of the carb. You need this foam oring or it won't run or idle right.
I have the same motor, or I think it is. But your prop hangs below the skeg where my skeg sits lower than the prop edge, so I can set it down and the prop will still spin. I wonder if mine is a 4.5hp instead of a 7.5 and has a smaller prop. Or did you put a bigger prop on it? thanks.
The motor from the video is with the original prop. You can check on the side of your motor, there is a tag with the model #. Type it in Google and you can find out how many HP it is. Thanks for watching!
@@BoatMotors It has no tag. It has 30psi compression in each cylinder and won't start, but when I bought it the guy started it. I think the rings are toast. I'm pretty sure now its a 1980-83 7.5.
@@murraymadness4674 Low compression motors are expensive to rebuild and I used them for parts motors. if you want to keep the motor and fix it you have three options: 1. You may have a bad head gasket. If that's the case you have to machine the head, get a new gasket and new impeller. 2.If the cylinders and the pistons have no damages, you can replaces the rings only. This is the less expensive option. 3. If the cylinders have scratches the engine block has to be machined. You need to get the correct oversized pistons and rings. In most cases the crank shaft assembly is in good condition, but if it needs to be rebuild you have to do it. I suggest you buy a new up and low crank shaft seal and new head gasket. Don't forget that two stroke are easier to work on than four stroke. If you don't have experience, sell this as a parts motor and buy a newer one in good condition. I wish you good luck!
Hey Tks for the video really helped me fix my 90 8HP, video really well done .
Bom dia sou do Brasil, tenho um desse motor e ele acontece de morrer igual no inicio do seu teste e a pera esvaziar o combustível também isso e normal ou tem alguma regulagem para não esvaziar a linha de combustível e morrer obrigado pela atenção.
The carburetor is very similar to this: ruclips.net/video/P_pIsOZ9FFI/видео.html The fuel pump problems are in this videos: ruclips.net/video/2Km5CdTYSiY/видео.html - 2 - ruclips.net/video/WNvlLv9Ass8/видео.html - The ignition problems are in this video: ruclips.net/video/VeJIS_-xZqM/видео.html - I hope all of this can help you!
Hey I have a Johnson 7.5 looks very similar I was wondering if you could show the safety pin system ( to keep the motor upright) because I can’t seem to get it working
I'll do it next time I have the same motor
@@BoatMotors also timming video please
The flywheel key snapped on mine and sent the throttle came through the side of cowling and I've been having trouble getting the timing back in order won't Rev out all the way now
Nice work so I do have a question... I picked up this same motor and have it running but the compression seems low to me... I did the test but didn't twist the throttle and got somewhere around 50 to 60 psi on each cylinder... Is it worth going through the powerhead to get compression up or just run it the way it is?
You have to twist the throttle to open the carburetor drosel. If you don't do it you will get wrong results. 50 to 60 psi is very low compression. Rebuilding the engine is expensive. Motors with low compression go for parts.
How many turn did you do back from all the way in on that idle screw I have the same motor please help
Around 2 turns
Love the rebuild! Can I bombard you with questions? Lol I've got a 7.5ho Johnson that doesn't seem to have enough top end
Sure, How can I help?
@@BoatMotors I have a Johnson 7.5 outboard. I tested the coils and it seemed to have low resistance, I replaced the spark plug wires, new plugs, cleaned the carb. It doesn't have a high-speed adjustment screw.
It doesn't seem to run at WOT. It fires up and under load it misfires and the spark plugs get black and smokey. I try to run about a 50/1 mix. I get maybe 5mph on my bass tender 9.4
It is a long shaft so it does sit further down in the water than I like but I'm not sure how to get it to run leaner.
@@FishHeadsIV Make sure you do a compression test. Follow the link at the end of the conversation, I know your motor is different, but you'll get the idea. Make sure you have a good spark in both cylinders. I hope you have the original carburetor and jet. Make sure the idle needle is adjusted well. If it is widely open it will pour extra fuel and the air fuel mixture is going to be very rich and the motor can not increase the RPM because it's flooding. That's why you have black and smokey spark plugs. I wish you good luck!
ruclips.net/video/LFdQrt82Z8c/видео.html
I have the same motor. I changed water pump. When motor is cold the water is runing after few minuts water is not runing. Do You know what can I do?what is wrong? The kolumn is very dirty like mix oil with water. The oil in down part is good without water.
Watch this video and you can see how to check and modified the cooling system. Usually the nozzle of the cooling system clogs. Most of the fishermen have a paper clip and unclog it from time to time. In most cases this is the problem. Some time the old impeller can lose some of the fins and they can clogged the cooling system. Some of the old owners probably had this problem back in the time and decided to sell this outboard motor. ruclips.net/video/lnFySjQXqlg/видео.htmlsi=9K_IBxjnfV_K9_GE
Hi! What should be the diameter orifice plug for this carb? Maybe you know
I don't sorry
@@BoatMotors no prob, I’m just trying find out why my john 8 have a top speed 29km..
ruclips.net/video/4AzdnBf3hWs/видео.html
ruclips.net/video/HDWW09qKnwc/видео.html
Hello does the power head need to be removed in order to replace the upper water tube grommet ?
Yes
Hey there, thanks for the video. I bought a 1985 8hp Johnson from a buddy of mine and I can only get up to about 6.5 to 7 mph . I know I should be getting up to about 15 mph top speed with this motor. It's on a very light weight 12' aluminum boat. I'm about to rebuild the carb, fuel pump and install a new impeller. I put new plugs in it but I'm still wondering if I'm getting enough compression in both cylinders. The plate on the lower unit is about 3" lower than the bottom of my transom just fyi. any thoughts that may help me?
Hi, you have a very interesting situation!
First - make sure you have good compression.
Second - make sure you have a spark on both cylinders.
Third - there is nothing wrong to clean, rebuild the carburetor and get a new impeller.
Forth - make sure when you turn the throttle handle the magneto plate is moving all the way the retainer link (part #0395883) and it is completely engaging the roller, cam follower (# 0323328). Make sure the cam follower (#0323327) is not broken or cracked. I'm pretty sure your throttle is not completely opened and your motor can't receive enough fuel air mixture.
Fifth - I'm sure that is not your problem, but make sure you have a fresh gas and oil mixture.
Good luck and let me know if you got any results.
@@BoatMotors Great thanks man!I’m pretty sure it’s the throttle mechanism I ordered a new cam follower, spring and clip because the one on there was broken I rig something up to work but I don’t think it’s working well enough. Also I did rebuild my carburetor and fuel pump I have a good gas a new tank and bulb so I don’t think it’s that. Although I don’t know but it’s a chance that the line is too big is 3/8”??
I had the oring break, that holds the cam roller onto its shaft (1.41 of this video). This will cause a massive loss of power, as the butterfly in the carb will not be able to open fully. Also, there is a foam oring where the black airbox connects to the front of the carb. You need this foam oring or it won't run or idle right.
I have the same motor, or I think it is. But your prop hangs below the skeg where my skeg sits lower than the prop edge, so I can set it down and the prop will still spin. I wonder if mine is a 4.5hp instead of a 7.5 and has a smaller prop. Or did you put a bigger prop on it? thanks.
The motor from the video is with the original prop. You can check on the side of your motor, there is a tag with the model #. Type it in Google and you can find out how many HP it is. Thanks for watching!
@@BoatMotors It has no tag. It has 30psi compression in each cylinder and won't start, but when I bought it the guy started it.
I think the rings are toast. I'm pretty sure now its a 1980-83 7.5.
@@murraymadness4674 Low compression motors are expensive to rebuild and I used them for parts motors. if you want to keep the motor and fix it you have three options:
1. You may have a bad head gasket. If that's the case you have to machine the head, get a new gasket and new impeller.
2.If the cylinders and the pistons have no damages, you can replaces the rings only. This is the less expensive option.
3. If the cylinders have scratches the engine block has to be machined. You need to get the correct oversized pistons and rings. In most cases the crank shaft assembly is in good condition, but if it needs to be rebuild you have to do it.
I suggest you buy a new up and low crank shaft seal and new head gasket. Don't forget that two stroke are easier to work on than four stroke. If you don't have experience, sell this as a parts motor and buy a newer one in good condition. I wish you good luck!
Could you tell me the part number for this carb?
www.marineengine.com/parts/johnson-evinrude-parts.php?year=1982&hp=7.5&model=E8RCNR