So I have a 2002 wr426sm that I finally built up but it's been acting up alot lately. When I go to kick it over WITH the choke on, it will sometimes seem like it has no compression. It will constantly just kick over even after TDC. When I try to kick it over before I turn the choke on, it has compression. Sometimes when I turn the choke on and turn it off and try to kick over the bike, it will continue or kick over past TDC with what it seems like no compression.
Once I pull the throttle about a half a turn or more, it finally gets some compression. Once it's heated up it seems to get compression again but usually only when it's cold it has the no compression issue. This issue has started to get worse for the past couple of days.
I have a 2004 yz450 exhaust camshaft in the bike and just got done checking the valves. They're all in spec. INT ~.10mm, EX ~.20mm.
I also took off the decompression lever because I don't really need it.
I'm suspecting it's a bent valve possibly?? Btw, the jetting is perfect on the bike. I took out the plug and it's got that perfect dark-tan color.
Let me know what you guys think..
Edited by dchooo, October 27, 2013 - 09:08 PM.