won't stay running
 

Ok, went riding the past couple days. After about 3-4 hrs of hard trail riding my 185S just stops running. It doesnt start back up until it's cooled off either. What would cause this? Every once in a while it will start (while hot), but only with the choke on and after about 30 pulls of the rope. Added note, when starting it you can hear something in the crankcase/engine spinning almost freely, like a whirling sound and then it clunks when it stops. Any suggestions where/what to look for?

won't stay running
 

i would think the clunking sound might be ur timing chain r piston hitting but have a shop take a look at it i dunno for sure.

won't stay running
 

hi i have a engine that does the same thing and its the coil it will get hot then stop working until its cooled off so maybe check wires maybe there chewed from mice so its causing it to short out. that might not be the problem but its worth the try? just check all wires to plug. another problem is your CDI box might be shot from all the use. just some suggestions hope this will help

won't stay running
 

When it's hot and stops running, do you have proper spark??? If you do, then it's probably fuel related (or plug).

When you say "Every once in a while it will start (while hot), but only with the choke on", that makes me think that it's running out of fuel.