2013 Yamaha 250 SHO fuel issue

[Flysooner9]

Motor will run fine until it gets heated up. Once hot if I idle for more then a few minutes it’ll die on me and not restart till I re prime the system. If I can get it to WOT after re priming (sometimes takes 2 or 3 tries) it will run fine until I go back to lower RPM’s.

so far I have changed the LP pump, all filters except vst, new fuel lines and primer bulb.

I also ran off an aux tank and had the exact same results. It seems to me like it’s vapor locking. Really beating my head on the wall on this. Please help. The most confusing thing is it’ll run all day at WOT.

 

[99yam40]

maybe this motor has a fuel cooler that is not getting proper water flow.
have you checked to make sure your tell tail is doing well when this is happening?

 

[Flysooner9]

maybe this motor has a fuel cooler that is not getting proper water flow.
have you checked to make sure your tell tail is doing well when this is happening?

I think it is a fuel cooling issue. The fuel cooler was blocked with sand from the previous owner and I unclogged that but I didn’t check the down stream lines very well. Should air pass freely through them?