650/X-2 Idle drops at WOT

I have been riding my wife's 1988 X2 650cc alot recently. I noticed that the throttle cable was adjusted to what I thought was a little tight (so that it prevented the throttle from opening all the way to rest on the carburetor throttle stop). So, I lengthened the throttle cable. And now when I squeeze the finger throttle it opens all the way to the stop.

Carb is a Mikuni BN 44 (I believe) with the K&N stack flame arrestor.

Works fine at WOT on the trailer with the hood off or on.

But on the water when I pull the finger throttle past where the cable used to stop it, the ski drops rpms.

At first I thought that it was not getting enough air for the additional gas which the carb is/should be introducing.

But now I wonder if it is the "rev" limiter or something else?

I need a decision tree to diagnose this condition. Any suggestions?

Also, BTW I have an induction timing light which has an rpm gauge on it, but it is not waterproof so I don't want to take it on the water. Any good recommendations for a waterproof tachometer to see what my actual rpms are?

Edit: I will post up a picture of the carb tonight. Hopefully you guys and gals can verify the carb make and model.
 
Last edited:
Top Bottom