jets are basically bits of metal with hole's inem,if the holes not big enough it wont flow enough fuel and bog down.if too big its like its flooding.bit of an approximation but thats roughly the symptoms.MY concern is your very specific symptoms.cuts dead at 50 and wont restart.then eventually you can start it.kinda sounds like partial siezure.wont restart till piston/bore cools down.that with you saying you rebuilt it makes me wonder.Has it been fully run in .partial seizure dosnt always lock up the back wheel.but you would loose compression.recheck when it cuts again to see if compression is lost.Not doubting or blaming your work.theres some funny shaped pistons out there.u could have been supplied with crap. simple test,when it dies,make sure you still got spark then spray a SMALL amount of easy start into air intake.if it trys to start then all mechanicals are good if it dosnt then somethings wrong inside.
caine, August 2008
