she just wont run

3 replies to this topic
  • whispers391

Posted August 30, 2013 - 05:19 PM


Hi im new to the forum. hopefully someone can help. starting from the top, I bought a 2000 wr400 and had it for 3 days. 1st day it ran perfect and never skipped a beat, second day no issues just putts around the yard a bit. day 3 it started running crappy, loosing a lot of compression quickly in a few hrs of riding till I could "kick" it over by hand without the decomp lever pulled. since then...

carb rebuilt by Yamaha dealer

new spark plug

new piston

piston rings

top end gaskets

cyclinder re-bored by us chrome (to new piston)

new valves

valves lapped

and I think that's it so far. at this point I still cant get it to fire. ive triple checked the timing( tdc with the I showing and lining the E's horizontal to the head facing left), theres enough compression I can stand on the kick start at tdc, checked spark twice and its nice and blue. when I took the spark plug out both times the plug was damp with gas and the bowl seems to have plenty coming into it. im pulling my hair out with this one! anyone have an idea about whats going on?





  • Krimble

Posted August 30, 2013 - 07:19 PM


Did you take the spark plug out and kick the bike over to see if it sparks?

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  • whispers391

Posted August 30, 2013 - 07:38 PM


ya the first time after I got the valves and everything in. and then tonight again messing around with it to double check.

  • whispers391

Posted August 31, 2013 - 04:20 PM


looks like the idler screw was adjusted way out and I was missing the timing chain tensioner bolt and brass washer, witch caused the chain to loosin up and jump timing. gonna work on her tomorrow and report back.


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