Air fuel Mixture Screws

I am wondering if anybody out there can help me out with a question. I have a 81 Kawasaki kz 750 4 cyl With the stock un-modified Kehin carb set up. I am in the middle of a rebuild on them. Yesterday I drilled out the air fuel mixture cap to replace the air fuel mixture needles. I marked the carbs from left to right 1-4. I counted the amount of turns on each of the air fuel mixture screws untill they bottomed out and noted the amount of turns for each carb. 2 of the carbs were 2 1/8 turns out and 1 of them was 1 1/2 turns out and the 4th carb was only 1 turn out from the bottom. I think taht is how it was from the factory because the aluminum block off caps were un disturbed with the original pink stripe across the tops of them. Does this seem right? I know that the drill bit did not interfere with the settings when I drilled the caps out. Does any body know the stock setting (how many turns) that I should start out with when installing the new air fuel mixture screws? Any help would be greatly appreciated

Thanks

Steve

del

Usually the stock setting is used as a good starting point. You are then supposed to adjust each one for best performance (highest idle). Maybe they were set correctly? That does seem like a big difference though. Maybe someone will chime in that has also seen this. Very interesting...

I remember reading somewhere that a good starting point would be 2 1/2 turns out. What do you think?

If you have stock pilot jets and stock airbox, I suggest you start at 1 3/4 turns out from very lightly seated and then once the bike is running again and the carbs installed, adjust each screw in turn; turn the screw in and out about 1/2 turn to find the fastest idle speed your ear can detect. There is no factory spec and the original settings are never very good.

I do not have the stock air box. It was missing from the bike when I got it, so I Bought some K&N Cone Filters from Z1Enterprises. should I still start out at 1 3/4?

Thanks
Steve

I also have "new" stock size pilot jets that I am installing tonight.

I doubt you have new stock size pilot jets as these haven't been available for about 30 years. The Keihin pilot jets in your assembly are unique to that assembly, and to a couple other assemblies from the early 80s. If you replaced your stock airbox with K&N pod filters, the question should be how to rejet. Since you can't change the pilot (call them slow jets on Keihin carburetors), change the primary main jets to #68 and secondary main jets to #140 and the bike will run as it should if all else is OK.

Thanks for all the advice. Do you know where I can buy these jets?

Steve

I orderd the Dynojet Jet Kit today. I am going to install this kit when I take the carbs off to fix the drip coming out of the nipple on the bottom of the #2 float bowl. Mods Include: Dynatek Ignition System, K&N Filter Pods and a Vance & Hines 4 into 1 Exhaust System. Should run pretty good.

Since you didn't follow my advice regarding how to jet the bike for the pods and pipe, I suggest you get the DJ tech support for the DJ kit handy. You will very likely need it hehe I have not heard of too many good reports from folks using DJ kits. Good luck.

Wiredgeorge, I hope my bike is the exception!!!lol
I just installed the dynojet stage 3 kit on my 84 gpz750 that has a uni aftermarket filter in the stock airbox and a 4 into 1 Basani superbike pipe.
I havent tried starting it yet because i just put a fresh paint job on the pipe and still need to install it but now that you mentioned people not having good luck with Dynojet stuff im frettin startin it.
I guess ill just keep my fingers crossed!!
The instructions in the kit said 3 turns out on the air screws? We will see........