bought a 250 tb with new top end,guy never was able to get it to start so sold it to me cheap.tried for about a week with no luck either.has spark gets gas and has compression.sometimes it will backfire thru carb.we have an old wore out 250tb that would run but had bad tranny,so ive borrowed a few parts with no luck any help would be greatly appreciated

 

You may have compression but how much? You need at least 100psi for it to run.

 

2 strokes are pretty simple, if your getting enough of a spark and the right amount of gas it should fire. what you should do is like 2manytoys said is try doing a compession test w/the engine cold and wide open throttle and you should have more then 100 psi since you said it just got rebuilt. just a thought, but you sure that this guy did a rebuild right? maybe he put the rings on w/ the gaps all lined up which would have blow by

 

havent done compression check yet was next on list,ive had head and jug off,has new piston and the rings are on properly.thanks will do compression test next.

 

idk if you mentioned how old this tb was, but a buddy of mine has a tb 250 also and was having some problems and he advanced the timing slightly and now it starts instantly almost every time, idk if thats what would cause that but i guess it sjust something to check.

 

Kinda defeats the purpose of a compression test now that you have it torn apart. If you do a test and it is low you have to tear it apart again.

 

i put it back together the first night,only takes a few minutes to tear down and reassemble

 

If hondaslayer ever gets on here, he should be able to help you. you could try sending him a PM.

 

thanks for all the help,seems the guy who i got the tb from had put a std bore in a bored cylinder.we took the jug off the old junk 250 and it is up and running.thanks again for all help.