So after running the bike for about 6 months (a few races and practices) since I bought it I thought I'd check the valve clearances. Needed adjusting so started the job. On lining up TDC I noticed the marker on the exhaust cam shaft sprocket didn't line up with the top of head as it should, the inlet was ok. Counted the pins of the cam chain between markers and it was only 14, should be 15. The exhaust cam was one tooth out!! Surprised the bike even ran, but actually I didn't feel any problem at all, in fact I even got a few holeshots and won a race or two!!
Just wondered if anyone has similar experience.
The bike is all rebuilt now, re-ground the valves/general clean up, but haven't ridden it yet so I don't know if it has made any difference, however I have noticed a feeling of more compression when kicking it over and seems to start easier.
Luke.
2007 RMZ450 timing out.
Started by
Luke San
, Feb 21 2012 08:54 PM
5 replies to this topic
Posted 08 March 2012 - 05:24 PM
Nothing unusual, the exhaust valves were slightly pitted, maybe a little hot, but still usable. This was the first time to rebuild a 4 stroke so I can't compare to anything really.
Posted 13 March 2012 - 09:47 AM
I have a '05 RMZ 450 and had a similar issue a few weeks back. The bike felt fine but the engine was a bit noisy so it was time for the cam chain to be adjusted. What I found was that my exhaust cam was spot on but the inlet cam was off by 1 tooth. All that sorted the bike now starts a bit easier and I can definately feel an improvement throughout the range.
Posted 11 May 2012 - 07:29 AM
i rebuilt one of those awfull 05 kx250f's and i found the intake cam spun on its shaft, just for fun i moved it around and found you can be about two to three teeth off either advanced or retarded and it would run i would have never guessed it could be that off and run, not to jack your thread but im looking at an 07 rmz450 guy says its got a noisy top end? he is convinced it needs a new cam chain, you guys know anything specific i should look/listen for?
Posted 19 May 2012 - 07:53 AM
Just bought an '06 RMZ450 for cheap ($900) because the previous owner couldn't get the bike to start......I ended up finding that the intake cam sprocket had slipped on the cam, throwing the cam timing off about 5 teeth. Just ordered a new Hot Cams intake cam, so this will be one of the cheaper used bike rebuilds I have done in a while! 
