Making a Kawasaki Z1 race ready. Again

Part of the freshen up process was to back-cut the worn transmission gear dogs...a worn one, then the process

How can you hold the angle steady by hand?

LarryC wrote: How can you hold the angle steady by hand?

i for one, built a little jig to hold the gears at the right angle in my press drill, swept across the dog faces with a shaped stone grinder. no missed shifts in 3 seasons....

I dont use a stone because of its wear, loses the crisp shape.
Hi-speed dental motor/coaxial cable/carbide burrs.
As a life long artist, I have good control. Even at that, bright light, strong glasses, a vernier caliper, machinist dye, and testing the fit throughout the process makes it work out fine.
Depending on the condition of the patient, operation takes about 7 hours. Too much to do at one sitting, usually about 3 sessions.
I have done this successfully dozens of times over the years on my bikes and for others.

The purpose of the back cut is to put an angle on the dogs. That helps them ramp into each other, pulling them into engagement. That's the angle I was referring to.

Takes one steady hand to maintain that angle perfectly on every dog so they share the load from the crankshaft.

On a drag bike, every other dog is removed on certain gears as well. Not the hot setup for street because of the back lash introduced. Also, only the up shift side gets cut. On a road racer it's both sides.

yes, that's the angle.
no, it's not easy.
yes, I have a steady hand.
I have cut these dogs by hand and disassembled the same gear set after some time and can tell by the wear patterns that it is successful.

when i was at Joe Mondello's head porting technical school he said that his friends called him

"the human bridgeport".

now i think that maybe arthurs friends also call him the human bridgeport :lol: .

but joe did some of his own dental work and ground his teeth for fillings and filled them!!!!!!!!

arthur,have you ever done your own dental work?



nice work arthur thanks for sharing.

leon

Out of my league, but here's an exaggerated illustration of back-cut angles on the dogs.




Good Fortune!

Info and pic from KZZONE --

TRANSMISSION UNDERCUTTING

Undercutting a transmission involves machining angels on the engagement dogs and slots to prevent the transmission from jumping out of gear under load. There are three types of undercuts available from APE

Racecut...
This cut is performed on the side of the dogs that are loaded on acceleration. Recommended for hot street bikes and drag racers, dwarf cars, etc.

Up and down cut....
Both sides of the dog are cut to also prevent jumping out of gear on down shifts. Recommended for road Racing.




kzzone.com/trans.html


Good Fortune!

dbsuperbiker wrote: the forks are '86 ZX10, gutted of the antidive and re-valved. They are stiffer than the orig forks...no more high speed wobble, but require extensive tuning to suit each track and keep the front end from chattering under high cornering speeds.
Vintage rules when bike refurbished allowed for same manufacturer's lower slider fork up to 40mm to be substituted in place of orig.
No, they are not close to modern fork performance...and very hard to tune, but the bike does not wobble

Great articles, thanks for contributing!

I'm trying to get the best performance out of my stock 75 by tuning what's there. The first time I had my bike up to 80-85mph I nearly wet my pants from the dreaded weave. I notice it alot on 45-50 curves, and sometimes on high speed straights. Was thinking of installing some RT emulators. Any input on that? Stock bike, tapered neck bearings, good stock swingarm bushings, no frame bracing. I have a lathe and tune my own MX suspension..just baffled by this.

Kidkawie wrote: ...trying to get the best performance out of my stock 75 by tuning what's there. The first time I had my bike up to 80-85mph I nearly wet my pants from the dreaded weave. I notice it alot on 45-50 curves, and sometimes on high speed straights. Was thinking of installing some RT emulators. Any input on that? Stock bike, tapered neck bearings, good stock swingarm bushings, no frame bracing. I have a lathe and tune my own MX suspension..just baffled by this.

Some links to info about speed wobble:
www.kzrider.com/forum/5-chassis/485651-r...vice-for-sure#485651
www.kzrider.com/forum/5-chassis/479527-r...00-ltd-wobble#479527
www.kzrider.com/forum/5-chassis/476857-re-speed-woble#476857
www.kzrider.com/forum/5-chassis/476841-re-speed-woble#476841
www.kzrider.com/forum/5-chassis/467462-r...peed-wobble-o#467462

Weave may be a different issue than wobble, perhaps due to over-tight steering head bearings, among other possible reasons.

Good Fortune.

dbsuperbiker wrote: I dont use a stone because of its wear, loses the crisp shape.
Hi-speed dental motor/coaxial cable/carbide burrs.
As a life long artist, I have good control. Even at that, bright light, strong glasses, a vernier caliper, machinist dye, and testing the fit throughout the process makes it work out fine.
Depending on the condition of the patient, operation takes about 7 hours. Too much to do at one sitting, usually about 3 sessions.
I have done this successfully dozens of times over the years on my bikes and for others.

Luckily, the GPZ750 cluster comes undercut from the factory... so didnt have to sweat here

What sort of art do you do?