1981 Kawasaki KZ750 Resurrection

[Nessism]

Got everything together and happy with the results. The ride quality is a little better, probably because the compression damping is more controlled.

[Nessism]

Installed the Race Tech emulators last weekend but still have some tuning to do. The KZ service manual says to use 10W oil but Race Tech recommends 15W oil for their emulators. Since the emulators only control compression damping, not rebound damping, I decided to use 12.5W oil and crank in a little more compression damping via the emulator spring preload. Got everything installed but discovered that the Progressive springs are now sticking out the top of the forks by about 3/4" of an inch (the height of the emulator). Pressed the cap down and got them installed but the front end of the bike is now riding higher than before. Since I don't want the front end to ride taller I decided to order new springs from Sonic. Rich (Sonic owner and GSR member) emailed me and said the GS1000 springs are identical size wise to the KZ springs so I placed an order for the .9 kg/mm rate springs. Update to follow...

[Nessism]

My KZ has a little over 25k miles on the engine. There is also some primary chain noise at idle (different from valve clatter). The noise disappears off idle. I'm told that this is fairly normal for this engine. The cam chain tensioner can also contribute to a noisy top end.

Yes, there is some primary chain noise. It has a very distinct sound. It has a plain bearing crank so no crank bearing noises like a GS though.

My bike doesn't have much of any cam chain noise per say. The speced valve clearances are about 3x that of a GS shimmed engine so there is a hint more valve clatter though.

Ed, have you noticed any gear train whine that seems loud compared to a GS? I've owned three of these bikes now ('82 750E, '84 GPZ750, '84 KZ700A, all of them under 25,000 miles)) and they all have exhibited a bit of whine to the tranny, particularly noticeable on downshifts.

My KZ has a little over 25k miles on the engine. There is also some primary chain noise at idle (different from valve clatter). The noise disappears off idle. I'm told that this is fairly normal for this engine. The cam chain tensioner can also contribute to a noisy top end.

[ron bayless]

Just took the first ride! Runs GOOD! Very nice driveability. First gear is tall but the clutch and low end torque manage easily. Speedo and tach needles are rock solid. Bike feels like a scooter compared to the GS1000.

Have some niggly things to tend to: fuel level warning light sensor leaks, so took it out, exhaust leak because missing the crossover pipe gasket on one side, need to anchor the clutch cable better, and the exhaust pipes only look so so. At any rate, it's a good day. Time to clean the garage...

Absolute perfection.

[Griffin]

The Honda CB750/900/1100 F Supersports of the early '80s have some of the clunkiest gearboxes I've ever encountered. I've owned three or them, and ridden a few others over the years. Compared to the same era GS and KZ gearboxes, they were light years behind.

My current 900F requires an extremely firm, deliberate (i.e. slow) lift with the toe to ensure a proper shift. I don't know how many times I've gotten the RRRROOWWWW-CLUNK! of a partly missed shift fully engaging a split second after the clutch is let out.

Annoying, to say the least. Particularly when you're accelerating hard from a standing stop.

[Nessism]

For some reason my '84 GPz1100 seems to have a notchy feeling gearbox. Not sure if this has anything to do with straight cut gears vs. a GS , It also seems that my GPz's gear shift throw feels longer than my GS1100E. Gotta' give credit to Suzuki gearboxes, they shift very smooth and quick. Even my '87 GSXR's tranny shifts SO sweet !

Suzuki seemed to have an upper hand over most other OEM's in terms of gearbox shift quality during the UJM era. This doesn't have anything to do with helical vs. straight gears on the clutch though.

I'll say that my KZ shifts wonderfully though, and adding the articulated shift mechanism had a very positive effect.

[Road_Clam]

For some reason my '84 GPz1100 seems to have a notchy feeling gearbox. Not sure if this has anything to do with straight cut gears vs. a GS , It also seems that my GPz's gear shift throw feels longer than my GS1100E. Gotta' give credit to Suzuki gearboxes, they shift very smooth and quick. Even my '87 GSXR's tranny shifts SO sweet !

[Griffin]

It certainly lets you know when you've shifted gears.

[Nessism]

Ed, have you noticed any gear train whine that seems loud compared to a GS? I've owned three of these bikes now ('82 750E, '84 GPZ750, '84 KZ700A, all of them under 25,000 miles)) and they all have exhibited a bit of whine to the tranny, particularly noticeable on downshifts.

Brett, Kawasaki uses straight cut gears between the secondary shaft and clutch, and straight cut gears make some whine noise. Suzuki GS's use helical cut gears, which are quieter. Problem with helical gears is they causes a thrust load, that's why some of the GS drag racer guys convert their clutch hub gear to straight cut like a KZ uses. Guess what I'm trying to say is yes, my bike makes that same noise. I sort of like it.

[Griffin]

Ed, have you noticed any gear train whine that seems loud compared to a GS? I've owned three of these bikes now ('82 750E, '84 GPZ750, '84 KZ700A, all of them under 25,000 miles)) and they all have exhibited a bit of whine to the tranny, particularly noticeable on downshifts.

[Nessism]

Haven't gotten around to looking at the fairing yet but pulled the trigger on some Race Tech emulators. Got a good price on a set off ebay, plus there is a $20 off coupon right now. Hoping the suspension compliance will improve a little up front. At any rate, something more to play with.

And speaking of playing, the valve train on this bike was a little noisy so I want through the valve clearances again and tightened things up. The speced clearance is quite a bit wider than the Suzuki GS's (.10-.18mm vs. .03-.08) even though the designs are very similar. Tightened them all up to target the lower half of the spec range. Not worried about them being too tight considering the considerable clearance. After tweaking the clearances engine sounds less clattery. Good stuff.

[Nessism]

Hi Ed
I've been away from the forum for a few months so haven't seen the pics of the finished bike before today... so just wanted to say amazing work!

BTW, interesting comment you made that the bike handles like a scooter compared to the GS...

Thanks Ivor! The scooter reference is in large part because the KZ is so much lighter than my GS1000. GS's for the most part are superior handling bikes compared to KZ's, but I think the 650/750 KZ's are the exception. They can hold their own.

My next project for this bike is painting and installation of a GPz style Maier faring. I want to fabricate some nice mounts so it doesn't look cobbled together. Coming soon...

[psyguy]

Hi Ed
I've been away from the forum for a few months so haven't seen the pics of the finished bike before today... so just wanted to say amazing work!

BTW, interesting comment you made that the bike handles like a scooter compared to the GS...

My 83 GPZ750 has 36mm forks,of course the KZ may be different.Tried my PDF manual but fork size wasn't in the spec's
Edit:yeah the KZ is 36mm to.