Jump to content
Sign in to follow this  

crf 250r wont start

Recommended Posts

hi i have a 2004 crf 250r and i cant get it to start anymore. checked for spark-spark is good. checked for fuel-its gettin fuel (cleaned out the carb anyway) i know what your thinking, its the valves-nope, just had the head rebuilt maybe 10 hours ago, checked the clearances they are fine. it feels like it has low compression cuz i can push the kickstart down by hand without much effort and im no hercules. piston and rings got about 20-30 hrs on em took em out inspected the piston it looks fine, i was hoping to see a crack in it to find the problem but its fine. rings look good. WHAT GIVES??? i cant bump start it anymore either

Share this post


Link to post
Share on other sites

Does it pop or backfire at all when you try to kick start it? If so check the woodriff key for the flywheel. That wouldn't explain why you feel the lack of compression though. Only other thing it could be are the valves sealing on the valve seats. If you have a bent valve, it will cause the same symptoms even with correct valve adjustment because the valve is not sealing to the seat properly. If you still have the head off the bike, put some water in the intake ports and exhaust ports with the valves in the head, and see if they leak water. This will show that the valves are leaking, and causing lack of compression.

Share this post


Link to post
Share on other sites

I have just went through this exact situation, after replacing my intake valves with Kibble White SS valves my bike would still not start. After double and triple checking the timing and valve clearance I noticed a considerable amount of blow by coming up around the timing chain (for some reason I decided to kick the bike over with the valve cover removed), Long story short I found the compression ring had stuck in the piston causing the engine to have no compression. Hope this helps.

Share this post


Link to post
Share on other sites

if your compression is good as well then i would say to check you cam chain tensioner... it happened to me. i didnt reset the cam chain tensioner when i reinstalled it, i took it out as a whole and put it in as a whole piece.. you have to draw it back then reset it once it is in place.. if you dont then it acutally puts too much tension on the chain causing it not start up.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...