TOPIC:

I have a 81 1000 shaft drive. It has carbs with 110 jets and an accelerator pump.
I also have a 1976 900 with a header, open pipe, Dyna's ignition, cams (I was told), and K&N pods. The carbs on it have 117 jets, no accelerator pump.

I may be gettting rid of the 1000, and was wondering since the 900 needs rejetted anyways, if I would be ahead to put the carbs from the 1000 on it and take advantage of the accelerator pump.
Also, what jets should I go with on the modified 900?

Thanks,
mike

Welcome to KZR, Mike. As far as your carbs if they fit why not try them. As far as the jets try what you have already if it works fine if not rejet as warranted.
Ride safe,
Les
Oh, nice screen name,,,

Well, my biggest thing was the addition of the accelerator pump. I am into racing cars, and was thinking wow, a carb with a pump, and one without, the one with the pump would be better. But if it's not like that, then I'll just leave it on the 1000.
I guess what I would like to know is "Would there be any advantage to the accelerator pump carbs vs. the standard carbs?"

Thanks Milkman

The pumper carbs were introduced as somewhat of a work-around for the emission laws. Kawi starting jetting their bikes real lean in the late 70's. The accelerator pump was added to mask the leaness by squirting a dose of raw gas into each cylinder under hard acceleration.

I have a set on my Z1 that I've been dialing in for a while. I have pod filters and a Kerker 4-1. Struggled with a lean/surging midrange. For the bike to run it's best it was necessary for me to clip the needle jet in the #5 position and bump the main from a 105 to 107.5. I've also had the 17.5 pilot jet from the get go which is the recommened size pilot jet for most 900/1000 carbs.

Since I've never really tested my bike with anything different than the pumper carbs I'm not sure how much different it would be. I can say however, that when I get the bike up on the cams and whack the throttle she jumps!

Post edited by: savedrider, at: 2005/11/16 01:38

The internal components of the carburetors in use must match the pilot and main jets selected. The 1976 KZ900 VM26 carburetors came with #115 main jets and #17.5 pilot jets from the factory. To rejet for pods/pipes with no baffles, perhaps #122.5 or #125 main jets will be needed. Your #17.5 pilot jets will be OK probably. The 5DL31 jet needle should probably be clipped to the 4th positon at the start as I am guessing the lack of baffles will put a flat spot in the mid-range. Really hard to predict with aftermarket cams...

The pumper carbs, as has been explained, deliver an extra squirt of gas when the throttle is first turned because the base jetting was so lean #102 mains and #15 pilots. You can clearly see the effect of EPA mandates from 76 to the late 70s when the ST came out... The #110 mains are about as big as you want and #17.5 pilots will help the starting and warm up where the pump has absolutely no effect since the throttle isn't really turning much.