grizz_lee

Member
Aug 15, 2010
2
0
Yz 250 fluctuating reving

Hello.
I've just bought this bike about 3 weeks ago its a YZ 250 97. It seemed fine on testing it before I bought it, However when I went riding at the weekend for the first time I found it was a bit of a sod to start and found it had a weak orange spark so I cleaned up the contacts on coil and checked the wires/plugs and now it has a white/blue spark although its not massive it starts 3 of 4th kick from cold.


The problem I have now is the revs fluctuate are are not steady! I have uploaded a video to youtube as I cannot really describe it.
(please excuse the state of the garage lol)

The forum wont allow me to post a link so I`ve put the link on my signature at the bottom


When out riding and totally off the throttle the bike sort of slightly jerks forward on each rev, But when given full throttle its responsive, but it doesn't sound as crisp as it should do in the powerband.

Oil and water are were they should be.

Any ideas or help would be greatly appreciated


I just hope I haven't bought a headache :bang:

Many thanks
 
Last edited:

eagles22793

Member
May 25, 2008
146
0
the reeds check them to make sure they are not burnt or chipped also check the routing of the trottle cable i had a yz250 and the trottle cable was caught around the mount of the tank and when i would turn the handle bars it would rev up really high
 

plynn41

Member
Jun 8, 2009
107
1
It may be getting air into the engine through the ignition side main seal, or through a crack in the rubber intake manifold. These are not unusual, but should be checked and fixed if necessary.
 
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