2007 EZ-GO ST350 valve seal replacement

[Kevin Whitford]

Hello, I have a 2007 EZGO ST350 workhorse,gas. I would like to find video or instructions for replacing the valve seals. This will be next step trying to remedy very heavy white smoke coming from exhaust shortly after engine warms up. Engine is very strong after replacing spark plug and cleaning carb, exhaust and air filter clean. Smoke remains shortly after engine warms up. Any info out there?
Thanx Kevin

[Gearhead1956]

Generally speaking bad valve seals/guides allow oil to seep into combustion chamber while setting. Then when engine first starts creates smoke that will burn off and smoke clears. Seal/guides generally don't leak enough for the engine to keep smoking.

So with you stating your engine smokes after worm up? not sure that's your issue.

Have you done a compression test?

[Kevin Whitford]

No compression test done. Mechanic suggested replacing valve seals first just to rule them out. He also felt that the cart was very strong after replacing bad plugs. He doesn't do that kind of work, so I was going to attempt fix myself. I am looking for good instructions or video of replacing valve seals and even compression test also.

[Gearhead1956]

Originally Posted by Kevin Whitford

No compression test done. Mechanic suggested replacing valve seals first just to rule them out. He also felt that the cart was very strong after replacing bad plugs. He doesn't do that kind of work, so I was going to attempt fix myself. I am looking for good instructions or video of replacing valve seals and even compression test also.

Here's the thing. A compression test takes about 15 min's to do. Replacing the valve seals is a job and requires some special tools. Without a way to hold up the valves when removing the valve keepers and springs you have to remove the head. There are ways of doing this. but if you fail to hold the valves up then the head has to come off!

So the compression test should be the 1st, easiest and least expensive thing to do. It will tell you if the valve seats and rings are in good shape.

Its been my experience, if the valve seals or guides are bad the rings and valves are right there too.

You can buy a compression tester for $25 and do the test yourself. All you have to be able to do is remove the spark plugs.

[Gearhead1956]

One other thing I should have asked, Is this cart lifted? Is the oil over filled?

[Kevin Whitford]

I'm guessing this particular cart EZGO st350 workhorse is normally lifted slightly. I will be draining oil replacing with 48oz as I read in other posts. As far as compression test, is there a procedure that I can follow available?

[cart around]

This guy will show you how to do a compression test. https://www.youtube.com/watch?v=PkmAxUU-TIY

[Kevin Whitford]

Big help with the video, thanx. I'll get back to you guys on the results. Have to get compression test gauge tool and feeler gauges.

[mlj427]

Check with places like autozone they will usually have tools like that to loan out for free just pay a deposit.
Good luck

[Kevin Whitford]

Results from compression test was good, 150psi in both cylinders. However, after draining oil I noticed a good amount of gas in the oil.