kz750 or gpz750 cylinders for a 650

are gpz750r cylinders the same as kz750 cylinders? i want to get a set to bore out to 810 for my kz650.

I think the fins may be more square at the corners on the GPz750, but AFAIK that's it.

I believe the GPZ jugs have different colling fin design than the earlier KZ750. Also, remember that the GPZ has an electronic tach, which means the head is different. Whether this results in a corresponding diference in the jugs is not known to me.

Probably not what you meant, but the GPZ750R is the smaller version of the GPZ900R, a watercooled 16 valve bike that shares nothing in common with the KZ750. The GPz750 is aircooled.

Post edited by: Lorcan, at: 2006/04/05 17:38

Don't forget also that the 650s are mostly roller cam chains and the 750s are mostly (all?) Hy-vo.

A couple more tid-bits to know about this swap. The 750 cams do have the tach. drive area cast into the cam but it's not machined for the gear. It could most likely be cut into the cam. The jugs are different for the different cam chain tensioner and rollers. The bottom one is a 650 with arrows pointing to difference in the two.Only the last year 650 has the hi-vo chain ehich would be thr best one for this mod but I think you could work it out on the other years.
Mark

Looking at that picture just reminded me of something I was thinking about a while back.

I wonder if the 650 block can be bored out enough for the 750 sleeves? I suspect that it could be, but I don't have any 650's to compare.

steell wrote:

Looking at that picture just reminded me of something I was thinking about a while back.

I wonder if the 650 block can be bored out enough for the 750 sleeves? I suspect that it could be, but I don't have any 650's to compare.

I would think it could, the 880 kit by aries used larger sleeves than stock 750 sleeves, and I think it could be put in the 650 block too, but Im not sure.
Scott

The 750 jugs fit the 650 cases with little work and the 880 kit should be able to made fit as the stude spacing is the same on the 650 and 750.
Mark

Hey Guys,
I think that the gpz750 has the hyvo type cam chain and not a simplex chain like a lot of the 650's have.
I think that there is a difference in the cam chain guies/ slippers between the two different style cam chains?

Cheers

Dave

Mark Wing wrote:

The 750 jugs fit the 650 cases with little work and the 880 kit should be able to made fit as the stude spacing is the same on the 650 and 750.
Mark

I was asking if the 650 cylinder block could be bored enough to fit the 750 sleeves, and was hoping that you still had both those blocks in the picture and would be curious enough to measure

Dave Sloan wrote:

I think that the gpz750 has the hyvo type cam chain and not a simplex chain like a lot of the 650's have.

I think that there is a difference in the cam chain guies/ slippers between the two different style cam chains?

AFAIK, all the 750's had the HyVo chain, and the 650's started using it ~1981

Yes there is a difference in the slippers, but there seem to be a number uf 650/750 hybrids running around, so I figured that people must be using the 750 slippers on the roller chain without any problems.

Hey steel it looks like you should be able to bore the 650 barrels to fit the 750 sleeves. I have them handy if you want me to measure something in particular.
Mark