KZ 650 performence rebuild ( HELP)

I have a load of gpz 750 parts coming in, Carbs. intake boots, cams. I was wondering if in order to put the gpz valves and springs in the 650 head will i have to get any head work done. Also what size of valve shims should i expect to have to order.

Also will the gpz intake boots fit my 650 head?

What other mods may i have to do to get this ol' skooter going.

Seems to me it would have been a good idea to ask about fitment BEFORE buying all the stuff hehe... I can't help with the cylinder head / valve questions but the carb holders mount holes will have to be elongated with a Dremel or file in order that the mount bolts fit. Hole offset is different by about 1/8".

any time you change valves in a head you are going to need to get the seats and valves refaced, I think reborn650 put the gpz cams in his, ut you have to change the cam gears I think, you might want to pm him to see all the changes he did to his bike

What case are you useing? I'm guessing that you are going to use the 650 case. If that is the case why dont you just shave the cylinder head of the gpz and slap that on with a thin head gasket,and degree the cams. When you shave the head you will be retarding the cams due to the distance of the cams getting closer to the crank. That means less compression due to the intake valve closing later. Use the gpz head this wy you can fit the bigger carbs. Also you dont have to see that ugly nipple sticking out the 650 for the tack drive that you will not be needing with the gpz cams.

Carb boots will bolt right on. You'll need a valve job so everything matches up. You won't know what size shims you'll need till the valves are in. Then put the thinnest ones you have in and measure from there.
Mark

Thanks every one i had talked to people before saying that the boots will fit. the reason i dont go with the gpz head is because the 650 one has smaller ports.
Does anyone know if the gpz valve are a direct fit also.
Anyone ever price how much it should cost to get my head milled a bit? thanks again

Hey odl666 - I replied to your pm, hopefully you received my message.

The Gpz valves have a larger diameter on the face so you will need to have a machine shop remove the existing 650 and install new larger seats that will accomodate the larger 750 valves.

The machine shop will do a triple angle valve job and lap the valves once the new seats are pressed in. At the same time, get them to mill the head as it will likely be cheaper to do everything at once. Bring in your Gpz intake valves and get them to fit and trim them. In my opinion all of these above mentioned jobs are best done by a professional as it is unlikely that you have the proper machining equipment in your home garage.

My guess is probably $150-$200 for all of the work.

You can do the shimming of the valves yourelf. There is a lot of info here on Kzr on this relatively straightforward process.

BTW - Some guys have gone as far taking up to 30 thou off the head. This is pretty radical and will definitely involve degreeing the cams and possibly claying the engine to ensure that the new valves aren't going to come in contact with the pistons. I took only 10 thou off to clean up the mating surface on the head and didn't have to worry about claying the motor even with my higher compression 810 pistons.

Remember to install a very secure plug to block out the tach drive fitting. I removed the tach gear but retained the holder, epoxying it into place then I put a galvanized pipe cap on the outside. You don't want to lose your engine oil (and eventually your engine) through the old tach drive opening.

If you have any questions fire me off a pm.

Cheers-Colin Firth - Ontario Canada