I hate 4 Strokes

[joesnuffy]

Since you still got some time and flywheel is off. Clean all the grounds on your ignition system. Make sure every ignition component is getting a good ground. I never asked but do have good spark on both plugs?? What do the spark plugs look like??

My yamaha golf cart 2 stroke wouldn’t run correctly. I rebuilt the fuel pump cleaned the carb multiple times. In the end it was a grounding issue. I had to make a ground harness that grounded the ignition pick-up (under flywheel) to the coil (on side of motor), and also to the starter solenoids (mounted on fender) it has 2 one starts it in forward one in backwards for reverse. All these components were in a different area under the golf cart seat. So them being grounded to one-another correctly did the trick. It ran fine for like 3 years then bam it didn’t. The grounds must have stopped working and that fixed it. It would run just not correctly. No wonder I’m almost bald.

Hope that helps,
Joe

[bullie]

Got a chance to run out and install the key late this evening. I forgot my spark testers and got sidetracked before I checked the compression. It has been one of those days.

Now, this is what sidetracked me. I had the owner crank the motor while I sprayed around the intake manifold and carb with carb cleaner. It would start and idle as long I had a light spray hitting the junction between the carb and intake. Maybe we have found the issue.

There is a paper gasket then an "insulator" and another gasket between the intake manifold and the carb. Suggestions?

[joesnuffy]

Sounds like you may have found the problem. If you have pics that would help. I would think new gaskets would be in order. If the insulator is a plastic piece it might need replacing also it may be cracked.

On my 4 stroke scooter the carb mounts to a plastic piece with a rubber neck both have to be checked for cracks. My plastic piece has an oring in it also. It may have orings on both side of plastic piece can’t remember.

Hope that helps,
Joe

[bullie]

quote joesnuffy:

Sounds like you may have found the problem. If you have pics that would help. I would think new gaskets would be in order. If the insulator is a plastic piece it might need replacing also it may be cracked.

On my 4 stroke scooter the carb mounts to a plastic piece with a rubber neck both have to be checked for cracks. My plastic piece has an oring in it also. It may have orings on both side of plastic piece can’t remember.

Hope that helps,
Joe

What I decided to try,before I saw your reply, was a thicker gasket. I made two out of some gasket material but only one would fit due to space. I put the gasket I made against the intake manifold and the stock one against the carb. They are on either side of the plastic spacer. The stock gasket feels like it is made of stiff construction paper. Not much to it at all. Not anywhere near the thickness of a carb gasket on an OMC. Anyway, it runs good now. I hope this works as I have put about 20 hrs into this thing. I love being educated but this bit of education requires hanging out over the water on the back of pontoon boat like a circus monkey. I just want it to go away…running mind you, but go away. Oh, the stock gaskets were both brand new, forgot to mention that. Maybe the intake manifold flange is out of alignment slightly or it may not be flat. I don’t know.

This thing has been a "lemon" as the owner calls it since new (2008). It’s kinda funny that 25 cents worth of gasket material might be all it needed.

Or, it has been mentioned that I could file the face of the flange flat if it is a little warped/uneven and then put in new gaskets and a new spacer. What do you think?

I think I would probably have to get in another boat to pull the intake manifold off. Kinda hoping the gasket is gonna work.

I will definitely take some pictures if I have to work on it again. Kinda like, "This is what the motor looked like before I began adjusting it with my 2 lb shop hammer." 😀

[amuller]

The best fix for this is to lap the carb flange, both sides of the plastic piece, and the intake flange on a surface plate, or some reasonable substitute like a table saw table, piece of plate glass, or whatever. Sounds as if that would not be very convenient in your situation. Filing can work but proceed with great care. Look the plastic piece over carefully. A new gasket made of some reasonably soft material may work, may be conformable enough to seal, and sounds like it may be working for you.

[joesnuffy]

Good job!!! I am glad you got it going. Persistence paid off.

Joe

[bullie]

quote amuller:

The best fix for this is to lap the carb flange, both sides of the plastic piece, and the intake flange on a surface plate, or some reasonable substitute like a table saw table, piece of plate glass, or whatever. Sounds as if that would not be very convenient in your situation. Filing can work but proceed with great care. Look the plastic piece over carefully. A new gasket made of some reasonably soft material may work, may be conformable enough to seal, and sounds like it may be working for you.

I will tell the owner this. And, he may decide to do it…on a new tab.

[bullie]

quote joesnuffy:

Good job!!! I am glad you got it going. Persistence paid off.

Joe

Thanks. I appreciate you guys sticking with me on this one. It has been an exercise in frustration.

[fleetwin]

Good work!

[joesnuffy]

We have all learned something me especially. A good mechanic can always admit that. No one thought of this issue and posted it. Well Done!!!!!

Thanks,
Joe

[Author]

Posts