29mm carbs

If my memory serves my 29's have 145 mains and unknown pilots. Runs a little rich up to 4000rpm and then leans out. Stock 903cc, individual air cleaners, open 4-1 pipes

wiredgeorge wrote:

Then you have the Kaw version of the VM29 for sure Roy. The bike wouldn't even begin to idle if you had the 2.5 cut outs. Those things start at about #22.5 pilots. You could probably go a bit bigger on the main jets as well... what does it do over 7K rpm?

First timer here. As long as we're on the subject, I have a set of 29mm smoothbores on a 77KZ1000. It runs a little "ragged" between the RPMS of 2500 or so up to almost 4000. This is steady state running, like easing through town or cruising behind somebody, not getting on it or accelerating is what I'm trying to say.

I'm assuming this is a carb problem, but then I don't know, which is why I found this site, extremely informative.

This is what the bike has;
K&N air filter copies, LTD Jardine 2 into 1 pipes, (that somebody knocked most of the innards out of, essentially straight pipes, sounds cooooool, don't know that it does anything for the power)stock motor. Great compression, valves clearances between .003 and .005, coil power mod, Dyna S ignition w/ coils. It has 20 pilot jets and 120 main jets. The slide is a 1.5 It takes at least two turns out on the air screw to get the bike to idle decent.

Bike has a bit of a lean spot off idle, other than that starts, and runs great, good power, good snap off idle. Just the steady state running listed above it seems to run a little lean and erratic. Not in all gears though???

I opened the 29mm carbs (many times) and checked bowl adjustments, cleaned or replaced many parts, thanks Z1 enterprises, and found that the needles were 5CN18's. Z1 sold me some DL31's (I believe, what ever is the proper thing for those carbs) Anyway the thing doesn't run much better.

I had the needles in the 1 down or towards the rich notch. I put them in the middle notch and it ran worse. i.e the "ragged range grew in RPMS and it doesn't want to idle unless the air screw is almost all the way in.

I'm wondering, since somebody was obviously into the carbs to change stuff did they change the needle jet as well??? It's supposed to be an .06 per the Z1 website, trouble is they don't have any,out of stock. I checked the needle jets and can't find a number on any of them. How can I know what's right and what's in there. Would it affect this?

Am I missing something else or something obvious?

Wrong pilot jets? Any advice would be greatly appreciated. It's a great bike, Original dark red body work, great chrome, just somebodys baby that never saw any real riding. I knew it ran a little bad when I bought it. I figured I could fix the running problems, but finding a good original bike is pretty hard, or pricy.

Thanks in advance!



Victor in W. Michigan

Post edited by: ThousandKaw, at: 2006/06/27 15:58

I ran 125 mains on my KZ1000 with 29mm's. This with velocity stacks and a drag pipe sidewinder (Hindle) all else stock except Dyna ignition.

With the mods described you should try 20 pilots and 120 mains with the needles in the middle. This seems to work for 1000's with a pipe (no baffle) and pods. I have used this seting on 2 different sets and had 1 set on 2 bikes.

idling around and at low rpm's my vm29's run alittle rough too. this must be the norm for these carbs. my carbs seem to work better at higher rpm's and with the throttle opened up more.

arobsum wrote:

idling around and at low rpm's my vm29's run alittle rough too. this must be the norm for these carbs. my carbs seem to work better at higher rpm's and with the throttle opened up more.

Thanks for the Jet sizes everybody. Say, would care to describe a "little rough"? Mine will rev like the Grim Reaper is following, but just idling through town in 2,3 or 4th and its sputting and popping.(2500 up to about 4000RPM) A good burst and its all back to normal, just steady state riding in those RPMs is what does it. 5th gear same RPMS, cruises along just as smooth as can be?

Sounds like the pilots are a bit small.
Wired George ckecked out my 29's while he was here and found the reason why they idle at 5000 rpm. A bit of tweeking on the carbs and a new spring and they idle great.
I installed them today and it just makes for a bigger grin factor.
I also installed the dyna off my project bike and adjusted my timing chain.
I am still taking it easy on the bike.
I took my son for a 30 mile ride and the bike was as smooth as silk.
ThousandKaw, go to Wired Georges carb site and get some good info. He can catch your questions better there.Just click on the link in his responses.Roy