TOPIC:

So I have kz750 what I was wondering when comes to the cams and cam chain guides why does the z1 have the gear in the middle of the cams and the head on my 750 have the holes for one but don't have one and could I put one on my 750 cause it just looks like a more stable system with the gear chain guide other the then the cam guide piece of plastic on the top my valve cover

It has holes, because the 750-4 engine w Hy-Vo cam chain is based on the KZ650 which had a roller cam chain thru 1980. The holes may not have threads cut into them. just a guess. never checked.

Roller cam chain vs the HyVo type (silent chain). The Hy-Vo is quieter & is supposed to last longer than a roller chain. Also, the Hy-Vo might be stronger. not sure. I think the original Hy-Vo chain by Borg-Warner was first used on the Oldsmobile Toronado (???).

FYI: the 2000-02 ZR750 has an upper slipper guide bolted to the cylinder head, instead of being fitted to the valve cover. I've wondered if that upper guide could be used on the KZs --- you'd probably need to use the ZR valve cover.

chain-guide.com --- 1.6.3 Inverted Tooth Chain (Silent Chain)

Cool info man

Back in 1983 or 1984 I built a KZ750E motor using the KZ650 crankshaft and camchain. All the mounting holes for the KZ650 top camchain idler were there and taped in the KZ750E head. I think I had to use a KZ650CSR valve cover to fit over the top idler because the standard KZ750E valve cover won't fit. Even the cutouts for the KZ650 camchain idler wheel shafts were still left in the cylinder block from the KZ750E. All those parts just dropped into place. I either used Turbo 750 or GPz750 rods the ones that sprayed oil on to the underside of the pistons with the KZ650 crankshaft. I used a 1.00mm over early model GPz750 pistons and rings too. I had to plastigauge all the bearings to come up with the right amount of clearance with the Turbo 750 rods and KZ650 crank. Don't remember if I ran '82 or '83 GPZ750 cams. I had to go to a KZ1000J electronic tach because the GPz cams had no tach drive gears on them.

It was a super strong motor built from all "stock" parts. I sold the bike to a great gentleman from some town way north of Chicago, and he rode it for years after he bought it from me. He loved it and took many a trip on it. Years down the road, I wondered the look of surprise that came over some tech's face who pulled the cams to do a valve adjustment on that stock appearing KZ750E that used to me mine!!!!

Great story Dr Gamma. Very cool, a 750 with a 650 cam chain and idler. That would be a surprise. On the other end of the scale I met Reborn650 a few years ago in Sudbury in Northern Ontario. He took a 650 added 750 cylinder block and bored it out to 810cc. I was lucky enough the get a look at it one night in his garage and it was impressive. Very cool with the roller cam chain and top idler.

To koloj's question - and Dr Gamma you could probably answer this - but I am thinking the HyVo cam chain in the 750/4 is designed so that it can only be gripped by sprocket teeth from below/inside the loop. This would mean that a top idler sprocket like in the 650 would not work with the 750/4s cam chain and given that the top or outside of a HyVo chain is relatively smooth that the rubber slider inside the valve cover is the best option.

On another note I wonder if we will ever see a HyVo final drive chain.

the 750 is an improvement over the early 650 roller chain, the plain plastic guides are much simpler, quieter and more reliable than all of the old sprockets and rubber rollers. Modern motorcycle engines use the same type of timing chain and guide scheme. The weak link ( if you can call it that) in the 650's was that roller chain, tensioner, and the rubber guide rollers.

I should also add that a Hy-Vo chain runs a much tighter tolerance than a roller and experiences less stretch while running, this provides more accurate and consistent timing.

As for a Hy-Vo drive chain... don't know if you can run a Hy-Vo outside of an oil bath. Someone could come up with a light weight o-ring hy-vo for a final drive. Hard to make a hy-vo lighter than a roller chain... and better than a belt.

You didn't use Turbo rods on 750E pistons unless you had rod bushings made up and pressed into the rods. The Turbo wrist pins are larger than the 750E.

750E and H up to 83 have the holes for the cam chain roller, 83 and new GPZ750 don't have the provisions for the roller chain, neither cylinder block nor head.

The HyVo chain has also been used in transfer cases on four wheel drive trucks since the seventies.