johnson gt 150

Ok I have heard all I really want to from these mechanics around here. So I have come here for some help. Motor starts right up most of the time ,a little smoke at start up but goes away. Runs fine at all speeds on occasion I get a warning beep ( several short beeps ) idicating no oil. Now the last two times I have taken the boat out I run it . then when I got to where I was going and shut it down it wouldn't crank back up. After setting for a while probably 30 minutes it cranked right up. Now my plugs I pulled them and there burning black and wet. and I do smell gas.

I don't want to be one to jump on its the VRO that is the problem but I am being told by alot it is. I know OMC put alot into the VRO and when things are right it works properly.

I think I might have another problem.

So my question is an anyone offer e any advice as to what might be my problem.

My other Quastion is does anyone know what the compression should be on the cylinders on a 1989 Gt 150 Johnson.

Thanks for any help anyone can give me

Re: johnson gt 150

ok this is just a theory, but..........that's a carb'd motor, right? let me ask you something, is your VRO pump plumbed directly to the intake manifold? Or does it pump fuel into the carbs?

Otherwise, I don't know how in the heck it can be responsible for flooding your engine.

Other words, I agree with you. My theory is, worn or misadjusted floats leaking a tiny bit of fuel into the engine.

Re: johnson gt 150

The fuel is sent to the carbs, Fuel line come off the VRO then tee's off to the second and third carb with an extra line going to something on the other side of the carbs.

Re: johnson gt 150

As far as the compression goes, as a rule of thumb, about 100 psi, but even more important, even on all cylinders, or within 10 percent.

Regarding your other question, is it the 150 that you are referring to?

If so, you are explaining the classic symptoms of heat soak. The 60 degree engines between 90 and 175 horse are prone to this due to their compact designs and their use of plastic carbs and manifolds.

What is heat soak you are asking? Seahorse5 explains it in great detail in the following post.

http://forums.iboats.com/showthread.php?t=232431

Re: johnson gt 150

Wet plugs indicate they may not be firing. Take a timing light with you the next time you go out. When you have the "no start" problem, put the timing light on each plug wire. See if you get strong, constant flashes out of each of the 6 plug wires when you crank the engine. Look for intermittent or weak flashes: they are a problem. Electrical problems generally occur after the engine is heated up. If you don't see a problem, look into the fuel system next. Your engine is in the years when OMC put plastic fuel bowls on the carbs. After many years, the bowls warp and do not seal properly to the carb body. They can leak fuel and cause running issues. Check them by laying them upside down on a very flat surface. If warped, replace them with the older all aluminum ones. (if you do get into this swap, note that the jet passageways are not drilled the same and some of your jets will not transfer. Also the plugs on the high speed jets are different.)