2000 suzuki rm 80 new piston rings top end kit bike wont run rite starts sometimes but only runs for a minuite or so then bogs out and wont start again .

Check the compression. Sounds like there is a lot of bypassed gas.

put compression gauge in spark plug hole and if its less than 100psi then you need a new oversized piston and rings ! gaskets also !!!

HI,,sounds like your plug is fouling,,what pre-mix ratio are you running? and has the carb been played with? run 32-1 premix and remove and clean the carb.

piston and rings are not to blame for this behaviour.

Hi, i presume that before you rebuilt the top end you had no issues? Normaly this happens when either you have exsessive play in either the big end or the small end bearing, this would be recognised by up and down moovment in the conrod for big end and piston for small end, this would account for spark plug contact only. The other thing to check was the piston identical in height to the old one, did it have the same cut outs for fuel transfere, and finaly did you install it in the correct direction with the rings located in the peg positions facing the inlet side of the barrel, was the new head gasket the same thickness as the old one, did you run i the new piston for a while if the piston and cylinder were new a bed in period must be observed

carbuator problem

make sure the timing is rite-du u hav a repair manual--also u must break in the bike like its new so the rings can seat-40mph for a few hundred mile

Are you locating the rings on the locating pins?? Have you "gapped" the rings??
When you say locked up I assume you mean seized??

when's the last time top end was rebuilt? could be piston rings are worn. also, make sure your power valve is clean.

i got a 2000 rm 250 and it used to be a cow to kick over i used to spend at least 20 min kicking to start it until i rebuilt the top end with a new piston and rings now it starts on the fourth or fifth kick if that doesnt help you need a new cpu good luck!!!!

Scatter gun approach > thoughts to check out > > >
Clean and dry the air filter? Go back to a stock main jet, at least to check things out? Are "O" ring seals on the main jet going bad?Partial internal collapse in exhaust (remove exhaust pipe & do a quick run down the alley), Install a new stock NGK spark plug, Be sure battery connections are clean and tight, Be sure intake manifold and carb are good and tight.

Hope this helps!