1985 Johnson 150 GT Rough Idle

[towens35]

My 1985 Johnson 150 GT Idles rough. I've been told that's typical for this motor. But, I believe it should be better. It runs great and will start and idle even when cold. I'd just like some opinions on this before I go to a mechanic.

[Rickracer]

The first thing I would do is pull the recirculation valves, check and clean them. They are the little "hose barbs" on the intake near the carbs with hoses that run to the bypass covers on the side of the block. I usually soak them in regular automotive carb cleaner. Just take the cap off the can and spray it into the cap till there is enough in there to cover the top of your recirc. valves. Depending on how caked they are with fuel and oil residue, you may need to soak them for a few minutes to a few hours. They are simply a check valve. You should be able to blow through them one way but not the other. If you can't get them clean enough to work, they will need to be replaced. While you're at it, make sure all the recirc hoses are connected and in good shape. If they are hard and/or cracked, replace them. Next, do a synch and link, following your service manual procedure. If these procedures don't take care of your rough idle, then you may need to go see your mechanic. :cool:

[towens35]

You are right I don't need no stinking mechanic. The recirc valves were shot 3 were clogged and 3 were straight through both ways. I finally got a factory service manual to do sync and link. Timing at idle was way off. Everything is running great. Thanks for the info.

[Rickracer]

Anytime :cool: