Engine problem
 

On a XT600Z from 1989. When the engine is full gas and above 6000 rpms, the engine misfires, lossing power, as if it were out of gas. The problem is very aparent on 4th going up hill, when you can go full gas without running over the redline for a while. Since, don´t know about other gears.

Further, going up the sema hill (at least twice a day going home), it use to need the 5th gear and pull strong; now, it would not go over 6500 rpms.

About 3000 kms ago, the engine was rebuilt, all clean up, and the regulator replaced.

Any ideas to start with?

Thanks

[This message has been edited by MA7008O (edited 30 September 2002).]