Rev limiter or to lean

I'm new at this site so be gentle. I changed to the Yz timing and snipped the "grey" wire on my WR 426 and took it out last weekend. I noticed at high RPMS that it was cutting out. It felt like a rev limiter but I'm not sure. I'm running the bike with the air box open, plug out of the exhaust and the grey wire cut also the throttle stop has been filed to yz specs. I never felt this before the timing change or the wire being cut. I left my jetting the same as I was running before. A friend told me he had the same thing happen on his 250f when he had filed the throttle stop down to far messing up the tps. My throttle stop was done at the dealer so I haven't checked the lenght. But again it didn't do this before the change. Any help would be great!!!!!!!

The throttle stop would be easy enough to test - when it is cutting out slowly lay off the throttle. If you get a burst of power your throttle stop was improperly modified.

As you said though, it doesn't make much sense that this would happen only now. I would revisit your valve timing job. I know of at least one member that allowed the chain to slip on the bottom end while doing the mod and messed his timing up completely.

When I made the grey wire snip on my WR250F - it made it MUCH easier to hit the rev limiter. MUCH. I had already changed to the YZ valve timing. Maybe you are simply hitting the rev limiter unexpectedly.

- Sean

Do yourself a favor and spend the $8 on the YZ throttle stop from the dealer. So you won't be second quessing the trimmed one.

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