Yamaha G5 dies when warm

[Jrdale08]

Hi all. I’m trying to diagnose a G5 that runs but when it runs awhile(generally an hour) it dies. It will run again after it cools down. Battery has 12.30 volts. When you drive it the generator is charging(generally a reading of 13-15 on the meter) depending how fast it’s running. Any thoughts?? Thanks ahead of time for your input.

[Leon willis]

Heat seizing or vapor lock is my that’s what I would say

[Jrdale08]

Good call Leon. We cleaned the gas cap up. See if that fixes it. Thank you

[Dave in VA]

Hook up an inline spark detector and see if it loses spark when it quits.

[SandbaggerYDRA]

Originally Posted by Jrdale08

Hi all. I’m trying to diagnose a G5 that runs but when it runs awhile(generally an hour) it dies. It will run again after it cools down. Battery has 12.30 volts. When you drive it the generator is charging(generally a reading of 13-15 on the meter) depending how fast it’s running. Any thoughts?? Thanks ahead of time for your input.

There have been cases of the TCI failing when hot. Check for spark when it dies.

[CP241]

Running for an hour straight? That seems like a very long time for a golf cart to run constantly. If it were a failing coil or TCI I’d think it would die and fail long before it’s been running for an hour.

Unless that hour is “on and off”

If it is constantly running for an hour straight and then dies, id suspect it may be overheating. It’s not uncommon for the fan to suck up dust, grass, dirt, and grime and it gets caked in the cooling fins in the block/cylinder and cylinder head. This would restrict airflow and not allow the fan to cool the engine properly. It’s a really old cart and unless the engine has recently been rebuilt, I’d be surprised if there ISN’T a bunch of stuff in there.

May or may not be the issue but certainly doesn’t hurt to check since it doesn’t cost anything except a little time to take off the cooling tins and see how much crud has accumulated in the fins