bogs out

[gregy133]

i just rebuilt the top end on my 01 rm 125 and now it starts hard the first time after sitting a few days but after i start it its starts first of second kick all day
and when i take off at first it acts like its going to die for a few seconds then takes off and goes fine untill i shut it off again
the carb looks clean and ran great before the rebuild

 

[ellandoh]

if it was mine the first thing i would try is shutting the gas valve off between rides. if the hesitation does get better between rides i would check the float height. if not i would go on secondly to see how it runs with the choke on. if that makes it better i would adjust the air/fuel screw or pilot jet. if not i would get back here and report detailed results and get more help

 

[whenfoxforks-ruled]

Jetting or mechanical?

 

[Howser]

do a compression check. how did the bike run before you put a new piston in it? did you just throw a new piston in and call it good or did you check your piston to cylinder clearance and ring end gap to see if it was in spec?