Stuttering after 20 minutes of riding

[JezCalder]

I Have a CRM250AR and recently it has started stuttering after 20 mins of riding.Sometimes if i play with the cables that go into the AR unit it seems to clear it for a while,Could it be as simple as needing a new spark plug or could the power valve/AR unit be sticking etc?? I'm not very mechanically minded and haven't had the bike long but the last owner told me they never had this problem,Any Ideas on where to start with this problem would be greatly appreciated as i want to enjoy riding it again!

[fallenmikethebike]

By "stuttering" do you mean a miss fire, or a lack of power as the throttle is opened?
Mike

[JezCalder]

It just jerks quite hard and lurches forward then stops then lurches forward etc,Its strange,feels like fuel has been cut!

[fallenmikethebike]

It just jerks quite hard and lurches forward then stops then lurches forward etc,Its strange,feels like fuel has been cut!

Have you had 2T trail bikes before?
Mike

[JezCalder]

Many 2T Trials bikes and 4 stroke trails bikes,I will change the plug today and see if it makes any difference

[fallenmikethebike]

Many 2T Trials bikes and 4 stroke trails bikes,I will change the plug today and see if it makes any difference

The A.Rs have a tendency to kick& buck when on an even throttle, they prefer to either be pulling or braking.
Mike

[gregorious77]

mine does it on the overun and its horible on the road. didnt always do it though and I suspect pilot jet too lean.

[fallenmikethebike]

mine does it on the overun and its horible on the road. didnt always do it though and I suspect pilot jet too lean.

They do have a tendency to emulsify on the inside of the jet.
Mike