kz tranny

:whistle: I was told by a local kz mechanic that by under cutting trans it would not last long :blink: reason for that is he says they com with a special coat from factory:huh: if it is not jumping out of gear and the teeth are not rounded weld the crank only:dry: WHAT YA THINK:blink:

cant you heat treat the gears after to make the surface strong again?
Scott

77KZ650 wrote:

cant you heat treat the gears after to make the surface strong again?
Scott

Gears have "case hardening". It is roughly .040" deep. They may have (new to me) methods for rehardening but by the original method any case that is there (like gear teeth for example) will be driven deeper. This will make the teeth brittle. A properly done backcut will last quite a long time though.

yeah there is plenty of fast bikes out there without undercut transmissions.if you are gonna make a lot of power with your monster or run a really sticky back tire id reccomend a billet 2nd gear over undercutting trans;)

What are you doing to the motor and how are you riding?The undercut is to help the gears engage solid when you shift,less likly to misshift this way.If your not going above 10.25:1 you should be alright.Ive hit 11000rpm and didnt have a valve hit a piston(I have heavy springs).I think its mostly for the drag guys.They run high dome pistons and if they misshift they run the risk of hitting. You can buy these at APE I think,They may be hardend.Call them and ask about it.Chime in guys if im off on this please.