popping through carb when warm.........

[jkidd]

Update.....

Courtesycart and Ruredy..........I just drove it till warm and pushed down on all valves. Valves moved easy but one of the intake valvs had kind of a dull sound when I immediatley moved my finger off. Kind of hard to explain. But the other 3 valves had a snap to them as they seated. It just sounded like it wasn't seating properly. Know what I mean? So, I will remove the head and inspect when I get the chance.
Once again thanks to all for the advise and info. It is greatly appreciated.

[COURTESYCART]

The intake valve on these engines are real soft, so if the Previous owner didn't keep the filter changed or fully seated the eng will suck debris in it and chew up the intake valves.

I had a customer this week bring me his valve to so me and they were mushroomed. Very worn and all but pushed back up in the head. He also needed new valve seats. They didn't put the air cleaner lid back on properly, so it sucks up sand. It is being used in construction site for comercial property. I think you get the idea.

Atleast you have some kind of lead.

[jkidd]

Got the head removed. Both intake valves are worn and mushroomed. I have ordered the parts this morning.

Can I lap the nw valves in by hand or do I need to get the seats cut or replaced? The seats are a little rounded but does not look too bad from what I can tell. What does everyone usually do about the valve seats?

[jkidd]

Got the new valves in and all put back together.......................................... ................................................


still the same problem!
Any more ideas? Only thing I havn't replaced is the pulsar coil. I guess that's next on the list? Anybody?

[ruredy]

Originally Posted by ruredy

regardless there's only a couple things that'll let pressure blow back through the intake on a 4 stroke and thats the valve not sealing or the cam timing is off.

it is possible for the press fit timing gears to move on the crank and balancer but this usually only happen when a rod is dropped and stops the engine abruptly. this would throw it out of timing always though. only other thing I can think of is a cracked head, valve seat, guide issues still. I don't see how the pulsar coil can blow gas and presser out the carb

[chardonite]

I think you now know the engine is mechanically sound so I think you should be looking elsewhere for the problem. The fact it gets worse when hot throws up a red flag for a electrical problem. Since resistance goes up with temp I would look hard at the pulser coil as the problem.

[COURTESYCART]

I have to agree with cardonite. what does the pulsar coil read when its hot?

I have not run into this problem with an ezgo, but i have a CC here that does the same thing and by the time i get all new parts on it the cutsomer could have bought a new cart. lol I have just ordered every part of the ign and fuel system new.

I know i hate just throwing parts at stuff, but you have an unusual problem. I have even talked to the ezgo tech rep for my area about your cart and he is even stunned. he's been doing this for over 30 years. I have even asked a few other in town that work on them ad they are pondering teh situation. to me teh only thing you havn't changed is the pulsar coil. How did the cam gear fit on the cam, was it tight or loose. i have seen the cam gear wear and cause all kinds of problems too, but when you look at it it is pretty obvious.

Is there any other update?

[Subarumouse]

Hello,

Valve timing offset because of a damaged splint?
The one on the clutch side.

Are the valveseats still on their place when hot?
(When closing, the valves could beat the seats up cousing a lack of space between valve and rockerarm)

Benno

[chardonite]

I think a compression check when hot and the problem is happening would be a good idea.Good luck.

[EZ-GOnewild]

Have you taken the engine shroud off and cleaned the dirt out of the fins on the cylinders? If it is packed with dirt/oil you may have an over heating problem. .02c worth.