1977 Johnson 75 Stinger dies when put in gear

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Sep 20, 2022
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I have a 1977 johnson 75 that dies as soon as i put it in gear in the water. I can run it in gear with earmuffs in the driveway, but not in the water. I have replaced the plugs, 2 coil packs, fuel filter, cleaned the carbs and replaced the gaskets and nothing seems to make any difference. Checked the compression and all three cylindars are right around 120. Tried doing a cylindar drop test, engine dies when the first plug wire is pulled, but engine has spark on the 2nd and 3rd cylindar, and if i spray ether into those cylindars with the #1 plug wire disconnected it will fire up and then sputter out. The fuel lines are clear since i had to remove them to clean the carbs. But i am running out of ideas of what to try on this thing.
 

racerone

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Dec 28, 2013
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It works in the driveway because the prop does no " work " when fanning the air !!!-----You may have an issue with water leaking into cylinders from exhaust manifold leaks.----Very common issue on those.-----.----You have confirmed that high speed jets ( orifice plugs ) found in the very bottom of float bowls are clean ??
 
Joined
Sep 20, 2022
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It works in the driveway because the prop does no " work " when fanning the air !!!-----You may have an issue with water leaking into cylinders from exhaust manifold leaks.----Very common issue on those.-----.----You have confirmed that high speed jets ( orifice plugs ) found in the very bottom of float bowls are clean ??
I had to clean them out pretty good when i cleaned the carbs, there was a lot of ethanol crystals in there
 

racerone

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Did you have the orifice plugs in your hands , taken out of the float bowl ?-----
 
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Did you have the orifice plugs in your hands , taken out of the float bowl ?-----
I did not, when i tried to get the first one out it was in there pretty good, not wanting to do damage to anything i left it in and cleaned it. Now i do have replacement plugs, if there could be more stuff in there i can takes the carbs off again and reclean and strong arm those out
 

flyingscott

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You need to do compression and spark tests. Look carefully at the old plugs make sure they are not shiny
 
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racerone

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Remove sparkplugs.-----Turn water on for the muffs.----Crank it over.----Does water spray out of plug holes ??
 

Crosbyman

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Nov 5, 2006
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I did not, when i tried to get the first one out it was in there pretty good, not wanting to do damage to anything i left it in and cleaned it. Now i do have replacement plugs, if there could be more stuff in there i can takes the carbs off again and reclean and strong arm those out
the orifice plug is just a hole" if you cleaned them they should be OK ... be focus on other stuff for now .
 
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