issues starting when hot

[quadrdr77]

needing a little help, im used to yfz450's and i now own a trx450r that is mx built. its an 05 with port work, web 208/921 cam, 14-1 piston and a dasa exhaust.
problem-1 i raced one moto saturday night and had to fill the radiator half way back up, noticed the fan isnt coming on could thermostat be stuck open?
problem-2 after the race the bike quit on me when pulling off the track and would not start back until it cooled off. my fcr carb thats on it does not have a hot start should i purchase one that does have a hot start and that is my problem? only asking bc this is the second race on this motor since being completely rebuilt and the first race it had a full sparks big core and started fine after it got hot but it was in the 50's for temp and last saturday night it was in the high 80's with 100% humidity.
the carm has dirt bike needle 2 1/2 out on air screw and a 188 main with 52 pilot. any help here guys would be greatly appreciated. thanks

[01boneless]

u can wire the fan to run all the time if u want thats what i did runs alot cooler.
and yes u should probley buy a hotstart assembly i think that will fix your problem

[quadrdr77]

yea i was thinking i was gonna have to buy a hot start assembly for it, problem is im gonna have to buy another carb for it bc the fcr thats on it doesnt have a spot for a hot start. i think it came from a yfz but not 100% sure

[01boneless]

yea it must have cam from a yfz. u could work on jetting a bit befor buying a diffrent carb. whats the plug look like?

[quadrdr77]

plug looks fine but its hard to get a good plug reading with race fuel. i went ahead and bought another carb from an 02 crf450 for it. found one for 130

[01boneless]

Originally posted by quadrdr77
plug looks fine but its hard to get a good plug reading with race fuel. i went ahead and bought another carb from an 02 crf450 for it. found one for 130
should be set then good luck

[310ESR]

Check the compression, the decompress might be set wrong.

[quadrdr77]

I'll check that when I put the new carb on. It didn't act like this two weeks ago when I went racing and it was a little cooler out side but I'll def check it. Thanks for the help guys