At what point does the trans need to be built?

Doing a 1170 with .435 cams, gpz head, rs36 flatslides, at what point is it necessary to do a billet shift fork, hd second gear? The bike's life will be 99% street use, maybe 1 weekend a year at the strip, I don't plan on a slick or anything, but I don't want to have to split the cases to replace something that I could do now while it's apart.

Then do it now.
Steve

rustedcutlery wrote: Doing a 1170 with .435 cams, gpz head, rs36 flatslides, at what point is it necessary to do a billet shift fork, hd second gear? The bike's life will be 99% street use, maybe 1 weekend a year at the strip, I don't plan on a slick or anything, but I don't want to have to split the cases to replace something that I could do now while it's apart.

I think you answered your own question... no time like the present if the engine is out of the frame and down.

What trans are you working with ? KZ "J" 83/84 GPZ ?

No matter what bike you are working on I would keep in mind that once the bike is riden the first time the trans is wearing. So if you want a good trans and don't want to split the cases in a year or two then do it now. A basic undercut is all you would need. Leave all the billet and heavy-duty stuff to the slick and wheelie bar guys.
80% of transmissions in motors I take apart are not good enough to be reused for street riding

Check for worn parts while its apart,fix what needs fixing. Save the billet stuff for the guys running a slick or really sticky 180 tires.

Well I think I'm going to order a undercut trans from pit stop. Ape charges more for just the machine work. I'm going to do the new bearings while I'm at it. Maybe someday I'll slap a sticky tire on for a weekend at the track, but as of now, I don't plan on it.

www.pitstopperformance.com/kawasaki-z1-k...ed-transmission-p-72

aperaceparts.com/transmissions.html

With all the other work you're doing, might as well spend another $300-$400 and get this done. I used to have a KZ900 with undercut trans. That bike shifted better than any other KZ I have owned.

Just put together an H2 motor. Measured the clearance between gears, carefully selected a shift drum and shift forks. Fifty miles later the trans jammed up. H2's and H1's are known for having fragile transmissions. Not wanting to split the cases again because of the trans, this time I sent it to Fast by Gast for undercutting and shimming.

Don't forget all the O-rings I think there is around a dozen.
If your case is from 78 or before I have a list somewhere.
JD

I'd do the APE over shift bushing while your in it
your shift fork's will like you for it.

I thought the 83-84 GPZ 1100 trani was already undercut from factory! I run a 1984 KZ 1100R motor in basically stock in my road race 1000J and love the motor. The trani shifts great and the clutch is surprisingly easy to actuate and doesnt slip at all. I'm running 31CR's and a 82 GPZ 11 exhaust cam for better pull out of the corners.
I looked at an 84 trani a few weeks ago and you can see the dogs are undercut from factory. Not sure about the ratios, if they are different from an 82 GPZ/J

bluej58 wrote: Don't forget all the O-rings I think there is around a dozen.
If your case is from 78 or before I have a list somewhere.
JD

If you have this list, I could really use it.