EZGO gas loses power when it gets hot

[Hedger]

1999 ezgo gas. Just have a fresh rebuild and it runs fine until it gets hot then loses power. has new carburetor new spark plug valves have been adjusted anybody got any ideas ?

[my1423]

I know you have listed that you already did, but valves are probably to tight.
Readjust them much looser and see if the problem still occurs..
You will also need to do it again after the second oil change.


If the issue is still there, how does it do after shutting off for 20 seconds and then refiring?
Still low on power or does it go well for a minute or two?

[Hedger]

When you say much looser, how much. Did the all the way down and 1/4 turn up .004 to start with.

[Hedger]

Problem is a little better after loosening valves. Started lugging down after about 20 min of continual driving if you tried to stop and go up a slight hill. Killed it for 20 seconds and it took off like normal.

[my1423]

Two external things to check, but i doubt,
1. a plugged gas tank vent. Loosen the gas cap and drive it.
2. plugged exhaust. If it is the header will usually glow cherry red after a few minutes of throttle. May also sound odd.

More likely
Running fine after a very brief shut down usually points to a thermal issue.
1. valve or valve seat issue. Try 10-12 thousandth for the lash and see if the issue goes away. if it does try 6.
Sometimes re builders may not have cut the stem length correctly.
May had substituted a different type vale than required with grows more when hot then stock.
2. Coil,
3. ignition cdi unit. Try an hei mod.

[Hedger]

I think the valve adjustment cleared things up on it. Seems to run great now. My1423, your advise is very appreciated.