Need help with strobe timing on 1972 9.5 HP Johnson 9R72M

andreipou

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Nov 26, 2008
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I have 9.5 HP 972 Johnson.
It has timing marks on the flywheel.
I can not find mark to align those marks against using strobe light.
I do not have original manual for this motor unfortunately.
Can anyone help please?
 

racerone

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Dec 28, 2013
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37,814
When using a timing light, it will always fire between the 2 vertical marks on the magneto plate.
 

andreipou

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Nov 26, 2008
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331
I still need help with this motor. Please read and tell me what you think.

I did some extensive work on it due to the fact that previous owner had little clue what he was doing, based on issues I found.
1. Replaced gearcase due to small crack. Re-seal kit, water pump kit, pressure test passed.
2. Replaced loose armature plate, coils, condensers, points, wires, plugs (all OEM). Timed with wire method and strobe light tested.
3. Carb soaked for 2 weeks and rebuild with OEM kit. Motor was breathing heavily what I learned is common issue with this design, so I drilled small holes in cowl right above carb air intake. It helped a lot.
4. Compression is 90/90 what is good for this type of engine as I read.

It runs good now, but it produces excessive amount of smoke (see pic). I am not sure what causing it. Water in the can gets very oily. I use 50:1 mix as recommended.

Any idea?

Thanks.
 

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saltchuckmatt

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Jul 19, 2019
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Try it on a boat.....motor needs to be adjusted on the water.

Smoke will clear up most likely.
 

cyclops222

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The smoke can also be steam. Overheated thermostat operation. Some cooling inlet water holes being blocked off.
Can you post pictures of sparkplugs ? Or how bad black build up is ?
 

andreipou

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The smoke can also be steam. Overheated thermostat operation. Some cooling inlet water holes being blocked off.
Can you post pictures of sparkplugs ? Or how bad black build up is ?
It is definitely a smoke....
 

racerone

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Need a fan blowing fresh air to the motor when running in a barrel.
 

Crosbyman

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Water in the can gets very oily.....
lots of fresh fuel and oil... goes out the window when entering the cyl on the upstroke.... making bucket water " oily" . that is why fuel injected engines are so efficient.

normal for 2 strokes
 

andreipou

Petty Officer 1st Class
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Nov 26, 2008
Messages
331
Water in the can gets very oily.....
lots of fresh fuel and oil... goes out the window when entering the cyl on the upstroke.... making bucket water " oily" . that is why fuel injected engines are so efficient.

normal for 2 strokes
I had a bunch of 2 stroke motors from 1.5 to 85 HP and know what you are talking about, but with this particular motor it is much, much more. And this is first 9.5 HP I got, so I can not really compare with the same type motor.
 

saltchuckmatt

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How big of a barrel are you using and how long have you been running it this way?

If it's been awhile since it's been under a load going full bore it will oil up pretty good.
 
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