TOPIC:

Hey Gang. I'm taking my bike to the 1/8 drags next weekend and want the old girl dialed in to perfection, or as close as I can get. This thing really flies but I have a couple little things I'd like to clear up this week before letting her wind out.

Here is my set-up; I have about 250 miles on the 810 kit, Kz750 cams and intake valves. Ported and polished 650 head, pipe, Mikuni 28's and velocity stacks. The springs are from a GPz 750 and I had to open the seat are a in the head to handle the bigger 750 valve seats on the intake side.

I am noticing a periodical flat spot around 5-6000 rpm (only when under full throttle, only when it is hot) and the occaisional popping I am getting through the #3 carb is possibly indicating a tight valve as the Dyna coils/ignition are working fine. The carbs are perfect as they came from Wired George.

I would just like to confirm the valve clearances with this cam/valve set up. I will be double checking every valve this week and swapping shims if necessary. Will the upper end mods I've done have any bearing on factory Kz650/750 clearance settings?

Cheers-Colin Firth - Ontario Canada
'77 Kz650/810 Wiseco

Look for 0.15mm clearance on all valves according to my Clymers 650 manual.

The valve clearance spec is based on heat expansion, since you are going to be running it wide open and generating lots of heat, I would set the valves at the high end of the specs. In other words, maximum clearance while staying within the specs.