Ok, so i just had to rebuild my 2007 RMZ 250(Cracked case).

I put in a new piston and rings, all new gaskets, new oil seals, new oil filter...The bike started second kick and seems to idle fine, its just when i go to rev it it shuts off. I re did the timing and it is set perfectly, now i can rev it alittle but it stills seems like it wants to shut off, and has alittle bit of a back fire every now and then, does anyone have any ideas what it could be? Thank you!

carb not jetted right is back firing or an air leak and sounds to me it only idling might be a jet clogged.

or hot start cable?

ohh i just cleaned out all the jets tonight, found some dirt in the quickshot though. I will be testing it on the bike tomorrow morning though...what could be wrong with the hot start cable?

if it was stuck slightly on it can make the bike run lean (back fire/pop) and have you ever held your hot start while the bike is running hot? usually will kill the engine

Edited by ontherev164, 19 May 2012 - 11:52 AM.

ohh no i havent even rode the bike yet actually. I bought it off someone for cheap because the case was cracked and the guy didnt have the time or money to fix it so thats what i have been doing, its the first time ive had the bike running actually haha...but i cleaned the carb out and now i have a new plug as well just in case, so im going to go throw that on and see what happens from there i guess. i will give an update in a few. Thanks for your help!