vm26 on a 810 motor - Need help with jetting

These VM26 carbs came from a kz1000 and I will be using them on my 810 build.

I'll be running the stock cams, stock airbox (hope to use the kz650 air box if it fits?), and a unknown 4-1 exhaust (I think its a Vance and Hines, no markings on it or labels doesn't look like a Kerker).

I'm at about 2400ft for elevation and just need some suggestions for Mains, Needles, and Pilot jet sizes to start with. I can wrench on stuff all day long, but carbs are my weak suit. Any help would be greatly appreciated.

I'd like to get some BS34s some day, but this is what I have to work with since the Keihin CV34s have shot vacuum diaphragms.

Thanks again!

I can't give you an exact jetting since my bike is not running yet but I did set up my carbs for pre start up. My setup is for 660ft - 831cc, VM26, stage 1 port work, .350" lift cams,stock exhaust,stock air box...

First off you have to get some 900-1000 rubber manifolds then you will see all the holes in the air box need to be opened up by about 3 mm on the diameter - the center lines don't change just the diameter... get a dremel and take it easy opening it up and stopping to try the boots once your close. You might want to mark the new edge with a sharpie before you start.

As for jetting I preset the float height and the slide sync... pilots are 17.5, stock needles on 4th clip, 120 main jet to start.

I ran the same setup plus GSXR 34 flatslides, pods, and V&H pipe with a 130 main and 22 pilots at 660 feet elevation.

Hope this helps...

This makes me think of another question - is the carb spacing identical between the 650/750's and the 900/1000's? Does this mean that the APE NOS Manifold will fit a 650/750 also?

Carb spacing is the same for KZ650-750-900-1000-1100.

No, the 900-1100 manifolds, stock or aftermarket will only fit with some grinding of the manifold mounting holes... they won't just bolt on.

So just mounting hole "corrections"? That's not too shabby...

Yeah, just slot the mounting holes by 2mm to get large manifolds to fit the smaller 650/750 head... We are talking just the stock 900-1000 manifolds for the VM26 or VM28 carbs here... not the CV carbs for the later model motors.

I was running 1000 J model manifolds and my ports opened up to 34mm but that requires running some kind of adapter plate. I used individual plates which were 1/4" thick with the mounting holes staggered. Those manifolds dwarf the stock units.

Thanks! Sounds like fun!

Thanks for the info on the jetting and the manifolds.

So since I'm at a higher elevation I would want to go a little smaller on the jetting size right?

Less air means less fuel needed if I'm correct on that...

Yes, for a higher altitude you need to be leaner in all carb settings. You have to be careful in that respect... better a bit rich than too lean.

You could start off on those setting I suggested because they would be rich and tune from there.

This little site has a good intro on tuning and has some useful stuff on altitude tuning - it may be of some help.

www.hondanighthawks.net/carb14.htm