Need help with rebuilding VM26's

After tearing my carbs down and cleaning out the gunk that was the result of the PO running without any fuel filters and torn socks on the petcock. I noticed that my carbs are not jetted any where near what they need to be. Right now it has a 107.5 main and a 15 pilot, the rest im unclear about as far as the needle jet and the needle in the slide.

What parts am i going to need for the bike to run good with a Kerker 4 into 1 and pods? And where is the best place to get the jets and stuff at?

Engine is a 76-77? KZ900...has a high engine number. Carbs are believed to be 77-78? KZ1000 VM26's. No air jet on side, engine is presumed to be stock....although i have no way of knowing. Cylinders have 903cc casting...so im guessing stock.

Also, what parts are the best to go ahead and replace while the carbs are taken down? The choke spools are in good condition....however the rubber caps are questionable.

What size are the o-rings that go on all the jets and the idle needle?

I basically need a run down on everything i need to know to rebuild the carbs part wise. Soooooo anybody want to help me out.

OH BTW...i found out why my bike wouldn't run worth a crap....my main jets on 1 & 2 carbs were laying in my float bowl.....:blink:

And to add, one of my bowl overflow nipples broke off clean with the bowl. About my only option is to find another float bowl right? Either that or deal with gas dripping on my gearbox.

Post edited by: Torch, at: 2006/07/19 22:48

get 4 K&L rebuild kits they have the parts complete and cost less than $20 each

yep a new bowl is in your future

dyno jet have the performance kit that contain needles and mains you will need to make it run right bout $100

trippivot wrote:

get 4 K&L rebuild kits they have the parts complete and cost less than $20 each

yep a new bowl is in your future

dyno jet have the performance kit that contain needles and mains you will need to make it run right bout $100

So the stage 3 kit for a 78 KZ1000 wouldn't run a little rich on my 903 engine? I really didn't find anything for 900's beside's stage 1 kits and i doubt they would even fit my carb since there all for 80's models. Wouldn't i just save money buying the jet kit and then just buying the gaskets, instead of an entire rebuild kit?

And i guess ebay is the only place im going to find a spare float bowl for a 26 huh?

Post edited by: Torch, at: 2006/07/20 22:04

stg 1 and 3 are in the same box the important parts are the adjustable dual taper needle jets and will run in your bike, just do not use the big main jets. rebuild kits are important for the float needles and gaskets and O-rings

mrcycleparts.com is a satelite linked site that goes to all motorcycle salvage yards here in america

you WILL find the bowl there

did they make 900s' in the 80's??

The bowls from any VM24, VM26 or a 78 Z1R VM28 can be used on your carbs, years from 76, 77 and of course 78 can be used as they don't have accerator pump ports on the sides.

The Stage 3 kit isn't a great option in my opinion. Different bikes use different carburetors. One of the main differences in different sets of carbs is the use of different OEM needle jets and jet needles. The needle jet is is the small orifice in the bottom of the venturi that controls gas flow in conjuction with the needle jet. These two components are MATCHED. Dynajet uses the SAME jet needle for ALL VM series jet kits.

This one size fits all approach means that one application will work better than another and using their jet needles becomes a crap shoot.

Needle jets have different STYLES and these are characterized in their badge number which will be three numbers followed by a LETTER/NUMBER. In general, all post 1974 VM series carbs used in Kawasaki Z and KZ models used "O" (letter oh) series needle jets which are smaller holes than "P" series used in the 73/74 VM28s on the Z1/Z1A. The KZ series used anywhere from 0-2 to 0-8 needle jets with the 0-8s being far larger holes than the 0-2 needle jets. Although I characterize the holes are much larger the difference in size is hardly perceptible to the eye.

Many of the stock VM series carbs with more performance orientation had mid-length jet needles that have smoother taper and are thinner. The Dynajet jet needles are far longer and thinner than the jet needles in a VM29 smoothbore, for instance. This means that they are FAR RICHER across the rpm range. This might be OK with the use of SOME needle jets but for others it provides horrible results. The 78-80 carbs, for instance (VM26) use pretty small needle jets towards the lower end of the "O" range and the skinny and long jet needles are particularly ill suited... it just makes them very hard to tune with a big flat spot over the mid-range. The other problem with the Dynajet Stage III kits is that the main jets tend to be way too big. Combined with the skinny jet needles, they mostly produce far too rich mixtures that waste gas and reduce performance in many applications. If the kits actually contained components chosen for a specific application, it would make some sense. As they are, I don't see them as a viable solution to jetting needs when you can reclip the jet needles matched to your needle jets and use larger genuine Mikuni main jets.

The last problem with the Dynajet kits is that if rejetting of the pilot system is needed, as it is when you install pods, they don't give you pilot jets which is pretty hard to understand given the price they charge for a set of "one-size-fits-all" jet needles and main jets.

The main reason their jet kits do well is that when rejetting is needed, most folks haven't a clue as to what size jets or what reclipping is needed. They install pods and aftermarket pipes, go out and find they can't pull 5K rpm due to a lean air/fuel mixture and then stick the VERY RICH Dynajet set up in and are able to pull to redline and are thus happy. In that sense, I guess these kits do serve a purpose but buying four main jets and the correct pilot jets is a lot cheaper and will rejet more precisely if the correct ones are chosen.

Wiredgeorge, you seem like you know a heck of alot more about these carbs than i do. Do you think you could give me an estimate on exactly how much you would charge me to get my carbs rebuilt and running right with the information i've provided you?

I saw on your site where you also tune the VM26's on an actual bike, so does this mean there pretty much ready to roll whenever i recieve them back....or do i still need to do fine tuning based on my elevation? I don't know the elevation where your located...but im at about 700 ft above sea level.

I feel confident on just rebuilding the carbs, but as for what jet's im going to need...im at a loss. Plus, i don't have any way of sychronizing the carbs...everything locally here is geared towards V-twins.

Torch, the proper thing to do is contact WG at his website via the link in his sig.

Same with APE Jay, Jeff @ Z! Enterprises, etc.

where as i do agree with most of what you said...i have purchased a stage 3 jet ket for my z and since installing it runs like a striped assed ape...although i agree with the taper on the needle jet...touch and go i guess..