1997 35HP Johnson won't idle...needs rich/lean screw adjustment.

dfrants

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1997 Johnson 35hp model J35QLEUR, 3 cyclinder, 3 carb, 2-stroke. won't idle. many hands have worked on this motor before so i want a good starting point. How many turns out from lightly seated should the rich/lean screws be set at? thanks, Don
 

racerone

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Does not go by turns on these.----Needle is set to a dimension.----What other trouble shooting was done ?
 

dfrants

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The last shop to work on it replaced the power pack($471.99) and the timing base sensor($334.99). Did a compression test 118, 125, 124. The last owner said it still ran like it was flooding out, the carbs look wet and there is fuel in front of the air box.
 

oldboat1

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not sure what a dimensional setting would be, but try setting the needles progressively leaner, 1/8 turn at a time and let the motor adjust. Repeat until a backfire or stall, then set 1/4 turn out. See if it's happier with that setting.
 

oldboat1

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about a centimeter. So presumably, adjust leaner a couple of millimeters at a time from the initial setting, looking for a lean sneeze.
 

dfrants

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thanks, i'll try that distance. I did my own compression test and the top cylinder only has 110 psi, the other two have 140. think i'm just chasing my tail trying to get her to run right...
 

racerone

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Time to take the head off for inspection.-----No head gasket just o-rings you might be able to re-use.
 

dfrants

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Ok, I removed the head. Someone before me already removed it at one time and two out of the three o-rings are damaged(the top one isn't even complete!) they used a black silicone to fill in the gaps. After I find three new o-rings, what should I use to "seal" it with? Will a thin coat of oil & gas resistant gasket seal work? Also, do you have the torque spec? thanks, Don
 
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dfrants

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the cylinder wall is smooth, i can rub my finger around it and can't feel any scoring or grooves. If it did overheat and cause damage, someone did a really good job smoothing it out...
 

dfrants

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Replaced the head gasket o-rings and torqued the head bolts to 20lbs. Now it has 130 psi on each hole.
 

dfrants

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I noticed a lot of fuel in the bottom cowl after running it. Closer inspection revealed that none of the bleed lines were there. can someone post the line routeing diagram?
 

dfrants

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Bummer...so I got a couple of plastic "tees" and hose and just connected the similar fittings.
 

dfrants

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motor sounds like its flooding, won't run for long and dies. i don't have the air silencer hooked up and when i tilted the motor up, quite a bit of fuel poured out of the drain tube for the air box...does this sound like a reed issue?
 
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