Hello,
I was wondering if any of you mach z fans could help me out. My friend has a 2000 mach z with like 600 miles on it. Here is the problem when you "tape it" the sled never gets above 7000 rpms. But if you say only go about 3/4 the thing rips and seems to be at the full potential. Any Ideas would be great?

sounds like the throttle cable is out of adjustment.

Sounds to me that you have a carb problem, possibe a pluged main jet.Have the carbs been serviced this year??

I must have misunderstood, I thought he said it goes to 3/4 speed and just kind of stays there. I've had that happen when the adjuster on the throttle cable came loose. But if it's bogging after 3/4 it's probably the main jets.

Just bought the sled used after the end of last season so I'm not sure when the carb have been rebuilt. When you are 3/4 the way it runs as if it's taped. It will beat our 800 twins like they where nothing and rpms are up where they should be, But if you just tape it all the way the 800 twins will win and the rpm's justt aren't there.
Do you think maybe just the jets. or should i rebuild the whole carb?

and your shure your not over reving?and the rpm stays steady