TOPIC:

Hi everyone, I need some help in getting a good idea of where to start with jet sizes for my project(I have Jeff at Z1 waiting on an order change). WG gave me a good place to start before I decided to go with bigger cams, but now Im not sure how many sizes to go up from that base point. current mods to my 77 650 include:
KZ750 cylinder block bored 3mm over using the Wiseco K810 piston kit
ported 650 head stock valves
MAC 4-1 pipe wide open
28mm carbs from a Z1R
individual pod filters
I was going to use KZ750 cams, but now Im debating over 2 choices of Web cams, either the 110 grind or the 189 grind:evil:

for the 750 cam setup I was told to go with #117.5 mains, #17.5 pilots and reclip jet needles to 4th slot. how much bigger for the after market cams?
thx everyone:)
Scott

Post edited by: 77KZ650, at: 2006/10/02 20:23

I've been down this road. I have a 78 KZ650 with the wiseco 720 big bore kit, RC 4 into 1 pipes, 26mm carbs with pods. I installed a Web cam, don't rememebr what number it was, I do know it was their road race camshaft. I was never able to dial it in. I could not get it to idle. It ran GREAT wide open but lower end I gave up torque and rideability. I tried every jetting combo to get it right but to no avail. I simply moved the problem around. I think the higher lift made little to no vacume. I finally gave up and installed milder cams out of a GPZ750. All my problems then went away. Now it's starts easily, idles great and has lots of power. Good luck

thanks, the road race cams are the 189 grind, a tiny bit more radical than the 110 grind, which are the street strip cams

I realize I don't have the same bike, but my mods are similar for the bike that I have. You can see in the signature, but I've got my 550 bored to 615, GPz cams and carbs, pods and 4-1 race pipe.

I am running the dynojet stage 3 main jets for a GPz 550 (recommended for pods and 4-1) and the fact that there is the big bore kit installed does not seem to affect jetting change a whole lot.

Basically, you are making your bike like a bored GPz750 with a 650 head. I would maybe try to use a set of GPz750 carbs and find a cheap dynojet kit on ebay (new of course). I don't know if they would work with your head though. More money and more work.. but a GPz750 head would be an easy answer, and probably make a little more power.

Hey Scott. In my opinion you might consider going with the bigger 750 intake valves and stiffer springs all around to match the better breathing potential the 750 cams will bring you. I would follow baldy110's advice and stick with the Kawasaki cams instead of laying out the pesos for the aftermarket camshafts.

As you know, I have the Kz750 cams with bigger intake valves set into my modified 650 head. This thing makes tons of power all the way up to 11 grand. This seems to be the ideal combination according to fellow Kz racers who have experience with the 650 head on the 810 bore.

With the Kz750 cams you can avoid the hassle of having to buy an electronic tach that would be needed with the Gpz cams. Following the similar set up I put together for my ride I can assure you will not be disappointed with the grunt throughout the power band.

Cheers-Colin Firth -Ontario Canada
1977Kz650 Custom with 810 Big-bore and lottsa hidden go-fast goodies in my old silver sleeper.

I dont plan on using the GPZ cams, I want something a bit more and going with webs still lets me run the mechanical tach:) you send in your cams, they weld more metal on the lobes, then grind it to their (bigger) specs.
I plan on using APE valve springs (VS900K) as Jay advised


A GPZ stage 3 jet kit wouldnt work even if I was using carbs from a GPZ because of the porting, and larger (then GPZ) cams

Ok, I've been talked into getting the 110 grind. What should I be needing for the carb setup now as far as jets and needle placement goes?
thx a lot
Scott

Post edited by: 77KZ650, at: 2006/10/04 15:38

bump
Is the grand master of carbs out there?