810 build questions

Hey guys, i am about to start the engine work on my 650 sr conversion to the 810 and i need to buy some things...i have read on a few other projects and on larry C's sight that a couple of guys have used 750 blocks as a base instead of the 650 blocks... is that a better idea? i have two spare 650 engines that i will be scavenging parts off of and need to know what block to buy.. both of mine have slight issues.... i will then use the 650 cylinder bored out and get the 650 head ported

ANY help would be appreciated! thanks in advance

If you keep the 650 block you will need sleeves (IIRC)... use 750 block and there is enough meat to overbore 3mm for the wiseco 810cc kit! (did it to my gpz 750 now 810)

regards,
laurent

I have a mint 750 turbo block for sale also you would be farther ahead to use a gpz750 head.

mint 750 turbo block

Do you have a mint GPZ 750 Turbo bike for sale ?:woohoo:

Just asking :laugh: :laugh:

regards,
laurent

as a matter of fact i just sold one .

would this block be a decent starting point for my 810 street build? and how much

I know there are guys who have done this - I believe there are certain model 750 cylinders that work better than others to swap onto the 650 cases. This had to do with the switch from the standard cam chain to the hyvo cam chain and related tensioner equipment.

You will need 750 (or comparable) sleeves to do the 810 reliably. This can be done by fitting the 750 sleeves into the 650 block or by swapping on a 750 block. I believe I saw that the 750 block *might* have a little more meat to it than the 650 block, but I don't know that for sure so consider it speculation until someone else pipes in.

It all depends on what you can get your hands on.

DFI can comment on the 750 turbo block, but I believe they were almost identical to the later model 750 blocks. However, that means it ran the hyvo cam chain (I believe) which your 650 may not (there were some 650s with the hyvo type chain I believe).

I would try using google to search for the following: "site:kzrider.com kz650 810"

Man, I never get enough of lmgtfy

There's always the 700cc kit for the 650, too. Much less work...

HyVo style cam chain started in 81 for the 650s. If a 650 has a kickstarter then it has a roller cam chain.

KZ750 cylinder blocks are the ones you want, same with the heads, GPZ cylinder blocks and heads don't have the provisions for the roller cam chain. To switch to the HyVo style cam chain you have to replace the crank, cylinder block, head, and cam sprockets.

And if you want a good 750 Turbo motor, I have one I'll sell

so early 750 blocks still have the roller chain cam chain and will work with my 650 head?

and how much for your turbo motor that would be fun

This is the same build that Im goin towards, just bought a 750 cylinders with the 810cc bore kit in it. Im hoping to use my 650 case and put the 750 cylinders on top it. I was just wandering if your making any progress with it?

bearshawk wrote: so early 750 blocks still have the roller chain cam chain and will work with my 650 head?

and how much for your turbo motor that would be fun

I wasn't real clear was I.

All 750 air cooled four Kz and GPz 750 motors had a HyVo style cam chain.
KZ750E and H from 1980-1982 have a HyVo style cam chain, but they have the places for the roller cam chain sliders and top cam chain sprocket to bolt on. In other words you can remove all the cam chain stuff from your roller cam chain 650 and bolt it in the E and H 750 cylinder and head.

83-85 GPz750 cylinder block and head does not have the provisions for the 650 roller chain components.
I don't know about the 82 GPz750, never had one of those.

$500 for the 84 or 85 GPz 750 Turbo motor in my garage


Oh yeah, if a KZ650 has a kick starter on it from the factory, then it has a roller cam chain. If a KZ650 left the factory without a kick starter, then it has a HyVo style cam chain.

81-82 were the conversion years.