RTV 500 fuel issue

[buckmaster27012]

For many years I've dealt with a fuel issue on my RTV 500 that only happens during the summer. On initial start it cranks fine, but if I park it and come back while engine is still hot it typically doesnt crank. I've learned that if I allow the fuel pump to run before turning the engine over it typically starts. If I forget or somebody else is using the RTV they dont do this and its done for the day, until everything cools and it starts right up. I've read and watched plenty of videos and I'm thinking of installing a check valve in the fuel line. I've seen where this is done to older cars that deal with vapor lock issues due to current fuel available. I've also tried non-ethanol fuel and did not fix the issue. My questions is there any harm in doing this? I will also be wrapping the fuel line to try to deflect heat off it.

Thanks

 

[General Lee]

Leaky injector maybe leaking fuel in the cylinder head? This can cause the symptoms you describe.

 

[MountainBuck]

Is the RTV at some unusual elevation?

When has the last time fuel filter was changed and injectors cleaned?

I don't think you will hurt anything shielding the gas line, but I would be reluctant putting in a check valve. Kubota engineers are some of the best.

 

[buckmaster27012]

Elevation is normal, the only filter on the system is in the tank on the bottom of the fuel pump. If gas was leaking by, wouldnt it happen all the time. As mentioned this only occurs during the heat of the summer, and have been able to relieve the issue by cylcing the key twice before trying to crank/start. Its like it gets vapor locked if you start to quick and no fuel in the lines.

 

[MountainBuck]

I have heard of those gas lines getting heat soaked after the engine is turned off causing bubbles, but I would think the problem would resolve quickly as the gas cycles back to the tank. Maybe your pump is not putting out the pressure it should.

IF that were the case, putting in a check valve may make the problem worse by adding just a small amount more of back pressure. Plus, I don't know that it would stop the bubbles.

Maybe your engine is overheating, causing the problem. Have you checked / flushed radiator, radiator screens, oil levels?

The fuel lines are rubber and deteriorate with time. Maybe they have lost their shape and are pinching. The manual says they have to be replaced regularly.

How many hours are on this machine?