Engine taking a long time to "rev down".

2005 WR450F

On the first ride, the engine is slow to "run down". i.e. if I'm reving and I pull in the clutch and close the throttle, it stays rev'd and just slowly.. over 5+ seconds works - works its way back down to idle. If I lug the engine a little with the rear brake or whatever, the idle goes right back down like it should.

I keep turning the idle down and it gets better. After 10 or 20 minutes of riding the problem goes away (and I maybe have to turn the idle back up because I've turned it too low).

Any ideas?

Jetting is too lean on the bottom...

Agreed, lean. Try turning out the idle air screw an 1/8 turn at a time, one or two test runs and it should drop almost instantly. You might have to set your idle speed again, but the idle should be good warm or cold. Good luck, and make sure your air filter's clean. :naughty:

I agree the idle would be the first place to adjust, secondly if you have played with the throttle cables recently or didnt pay attention when remounting them after some carb work, you may have the pull throttle cable to tight, it will pull for a bit and settle in after riding for a bit, just needs to be lossend up. :naughty:

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