Hot start issue

85 xj700n. Starts and runs great when cold. If I stop and leave it for about 30 minutes hot it won’t start. Good battery and starter. What’s going on?

 

Kinked fuel line?

 

Don’t think so. Line looks good and it runs great once it starts. When it does this I can let it sit for 30-45 minutes and it usually fires off instantly.

 

Plugged gas cap vet? Or, if a Cali model....and still has the original emissions control system installed, something plugged in there or the "anti-rollover" valve.

 

I opened the gas cap and it popped once but didn’t start. Don’t think it’s a Cal model. How would I find out?

 

Just curious, could a close to lean setting of the pilot screws be an issue?

 

I had a problem like that on my 750 originally.
The turn off and won't start after a while.
My problem was flooding when hot.
The bike would start if I opened up the throttle a lot when cranking, kinda like flushing air in.
Try that out.

 

Sounds like a possibility. Used to do that with old cars that flooded.

 

Think I found the problem. Although my battery cranked the engine well, it apparently didn’t have enough power to fire the plugs at the same time. When I finally put a meter on it I got just a little over 12 volts, but it dropped to about 9.3 under load. I had noticed that sometimes it tried to start just as I let off the starter button and that’s what led me to checking the battery. With it cranking the engine well I just assumed the battery was good. Lesson learned. With a new battery the issue seems to have been resolved.

 

Wow. Fine line on the voltage that's for sure.