carb setup??

Im new hear and have spent a lot of time reading and searching the archives. Ive found a ton of helpfull info, so hear goes. Im nearing the end of my project and trying to fine tune my setup. I have a 78 kz1000 ltd with i think to be the 26 carbs. i just did a full rebuild and tuned them the best i can. The bike seems to be running strong and smooth but im unsure that i might be a little lean yet. Here is a pic of my plug, and here are my specs. I have a brand new vance hines 4 into1 sidewinder with unpacked baffle and modified airbox not pods but better breathing and diff filter the rest is stock. When i did the rebuild the mains were 102.5 and secondarys were 15 my kits came with 107.5 and 17.5 so i used them to try to rich the mix a little. According to several posts here i think my 17.5 is close but i think my main should be around 120. looking at my plug is this correct am i still too lean? All i need is an educated start point

Post edited by: krazyjay99, at: 2007/09/02 15:54

Pilot is close. I would bump the main jet up to a 117.5 or a 120. Looks a little lean still to me.

is this plug from a main test or a pilot test? remember we are talking 2 completely dif systems here.so the plug must be run on only 1 system befor checking.
i like to put a piece of tape on the grip and mark off 1/4 ,1/2 ,3/4 throttle positions so i know EXACTLY wich circuit im runnig on.
to check the pilot u must cruise at 1/8th throttle (with a new plug)for about 10 miles then stop and check the plug.u are looking for a tan color way down at the botom of the insulator.if it is white richen the pilot air screw 1/2 turn and try again with the same plug.if it is rich u will have to use a new plug and go leaner 1/2turn.when u get close u can go a 1/4 or 1/8th turn .i would only do 1 cyl untill u figure it out to save money on plugs then try them all.if u get the air screws so lean that it idle too high then u go with a bigger pilot.
then u can repete at full throttle.this get harder.u will run out of rpm and have to slow down fast and repete several times to get color on the plug.
then when u get that figured out u can run at 1/2 throttle (same way u do full,several passes)and play with the needle clip position.
if u have to move the needle clip u should redo the pilots.
actualy if u find it is not running to bad i would check each system once to get a base line.then start from the mains and work your way down.

that plug is white on top and black down deep.this tells me u used 2 carb circuits,1 rich and 1 lean.
the soot around the outer thread can be from the plug not being tight enough.
good luck. and keep us posted.
ps. be carfull u dont cross thread a plug.