vm29's with accel. pump?

cgi.ebay.com/ebaymotors/Kawasaki-kz-z1-9...000-carburetor-carbs
these are a set of vm29's with accel pump(?) anyone ever heard of them? i was thinking of bidding on them. i would appreciate some input first. thanks.

Post edited by: arobsum, at: 2006/01/05 21:37

I have a set of VM29's with acc pump... well I own them anyway, they are out on loan right now :laugh:

your link didn't work for me but if this is them, ebay #4602389948 .... they look like 28's. 29's have the large bowl screw/drain that allows you to change jets with the carbs on the bike.

so these carbs are 28's, not 29's? then i guess all 29's have the large drain plug on the bottom...mine do. i had never heard of 29's with an accel. pump. thanks for the info. Item number: 4602389948 these are the carbs all right. it says vm 29..has the vm26 style bowl on them.

Post edited by: arobsum, at: 2006/01/05 22:05

Mikuni sold an add-on accelerator pump kit to fit many different carbs. You don't see them too often now.

ive got a set of 29 smooth-bores with the pumps on them

so the bowl style would change with the accel. pump kit? if this is true..are there other ways of telling which is vm29?

How do you 'kit' and acclerator pump setup on a stock set of VM carbs? How would you install the nozzles in the venturis?

The accelerator pump is designed to add a squirt of gas off the closed throttle position and is necessary in jetting situations where the jetting is lean in order to avoid flat spots and backfiring; especially off idle. The spray of gas is of short duration and the pump adds nothing once the bike is accelerating hard. There was a kit for the VM29 smoothbore but it wasn't widely sold as there was no real reason for it. VM29 smoothbore jetting was never affected by govt regulation since they are "race only" carburetors. The carburetors pictured in auction 4602389948 are 79/80 VM28 accelerator pump type. They are not smoothbores. One reason that folks mis-identify the regular VM28 carbs as smoothbores is that when they measure the ID of the engine-side venturi, they measure it as 29mm where it is actually 28.7mm which is the normal size for VM28s. I have never heard of Mikuni selling a kit for a VM28 or any other of its regular VM series carbs although they may have. The carb bodies would have to be drilled to accept the spray nozzles and since these nozzles fit into an irregular shaped hole, I doubt anyone could do this with any accuracy so I doubt it would be easy to fit a pump kit. The indentation that the nozzles fit into is sort of half moon shaped... This shape allows fitting the nozzles precisely so the little spray hole is facing the correct direction. It IS possible to convert VM28 w/pump to non-pump by swapping out the internals and making them the way they should have been set up if the EPA had not been scaring Kawasaki. The tuning of non-pump VM28s is a bit easier and they run great. This includes swapping the jet needles and needle jets and rejetting.

Years ago I purchased Mikuni accelerator pump kits and I installed them in my two sets of Mikuni VM29 carbs. Found the installation, including pressing in the spray nozzles, pretty easy.

These pumps were of help, especially in the lower 1/3 or so part of the throttle's range, where imperfect jetting existed in my earlier carb tuning days.

But I did not feel so bad at the time, especially after reading about the all problems the Yoshimura crew had with their VM29 carbs below 5,500 rpm in a November 1978 Cycle World Magazine feature article about a Yoshimura hot-rodded Kawasaki Z1-R KZ1000 vs. a Vance and Hines' hot-rodded Suzuki GS1000EC.

I sent the seller an email. I am just waiting for the seller to send me a email telling me that I don't know what I am talking about and so on.

you folks are a lifesaver. there are alot of people, including myself, that would have bid on these thinking they were vm29's. some folks would have bid pretty high too. the last 2 sets of vm29's i saw on ebay went for over $300.00 apiece.