VM29 Smoothbores

I need to know what is the baseline start point for these carbs (mainjet size/pilot jet size).
I'm running 4x2 exhaust (baffled), KN pod airfilters.
As far as I know the engine is a stock 79 KZ1000 LTD.
Now if the bike is not running #1 carb floods and runs out the airfilter. Spark plugs show it's running real rich.
Is there some way to set the float levels without having the tube adapters for the bottom of the bowls to do a fuel level check???I have installed new needles and seat(2.5). I have tried moveing floats from #1 to #4 and still #1 floods. Bench set the float levels at @25mm now @1,3,4 floods WTF.

When I got the bike it had flat camlobes on a couple of cylinders and the cam chain sprocket were slotted to allow the cams to be degreed. I have since changed cams
so I'm not so sure this bike is stock or not..I put stock cams in. If I put new plugs in and start the bike right away, it runs like scalded dog. The bike will idle fine and the longer it idles the more fouled the plugs become.

Post edited by: HOGEATER, at: 2007/08/27 05:55

go here for jetting info

www.z1enterprises.com/reference/z1-carb-guide.aspx

u must get the float needles seating properly first.u can remove carbs hook up a funnel or container to the fuel line and add water over a sink with the 1 float bowl off.now gently lift the float to seat it's needle. they have springs so dont push hard enough to bottom out the spring. see if the water stops flowing .if it does go on to the next 1.if it does not try cleaning the needle and seat or replaceing with new.
when u are sure they seat properly they will not over flow unless u have the levels set toooo high.
the plugs will normaly look rich if the seat leak.

A stock KZ1000 with a 4 into 1 & pods will use a 20 pilot % 120 mains.This is the setting for the Kaw carbs not the Suzuki ones with the bigger cutout.

I'm about ready trade these off for something I can get to run on without leaking all over.

I've tried setting float levels and leaving the drain plugs out to check for fuel, the carbs I do get fuel from i put the drains back in ;the ones I don't get fuel I readjust the float level a little more then install drains. the carbs either give too much fuel and flood or none at all. I've tried to isolate if it is the float itself by moving from a carb that floods to one that doesnt and the flooding remains at the same carb.I have new needles and seats... the carbs are flooding up into the throat of the carb..
I'm about ready to shred these for scrap..HELP

dude ... i'll trade ya a set of 28mm Mikunis off a Z1R for them! They are clean (on the inside)and ready to bolt on. Have chrome bowls and caps.

Can't blame a guy for asking ...

This may sound elementary, but have you cleaned them with Gumout (autozone) or some other kind of cleaner?

I just had a similar problem a couple of weeks ago, REALLY IRRITATING WHEN YOU'RE PLANNING A RIDE AND YOUR BIKE STARTS PEEING ALL OVER THE PLACE!!!!!!!

Anyway, took the bowl off, floats out, needles, seat, and cleaned them with carb cleaner. Put it back together and no leaks for two weeks so far.

Also, when you have the floats off, roll the float pin on a flat surface, if they are bent they will make the float stick. Sticking floats will make your bike pea all over as well. It's either the needle seat, needle, or floats man. Dont give up you'll get it.

HOGEATER wrote:

...have new needles and seats...

For the time being ---
Forget jet sizes.
Forget float level (unless grossly too high).

Here's the bad news -- Notwithstanding new float needles and seats, the float needle/seat interface is defective when fuel is being allowed to pass through the interface when it's supposed to be closed. As known, smoothbore float bowls are designed without an overflow arrangement in order to allow a large easily removable bottom plug for quick change of the main jets via the bottom hole. This is okay for racing applications, but sacrifices convenience for lack of overflow protection. So without overflows, any fuel leakage past the supposedly sealed float needle/seat interface goes into the carb throat and flows to the air filter and/or into the combustion chamber, either of which may allow fuel intrusion into the crankcase oil. With pods, the excess fuel through the air filter drains out the pod. However, excess fuel reaching a stock airbox may drain straight down the crankcase vent hose directly into the crankcase (my reason for disconnecting the stock hose connection between bottom of airbox and crankcase vent, and running a hose direct from the vent to underneath the bike). But this doesn't cure the problem of smoothbore overflow from reaching the crankcase via leakage into the combustion chamber. Some smoothbore folks replace their float bowls with the more "standard" bowls equipped with overflow tubes. Religiously closing a properly operating petcock while parked will obviate the excess flow through a leaking needle/seat interface (by disallowing fuel from the tank) on most any style carb --- BUT without overflows, a seriously leaking interface will allow fuel intrusion into the crankcase while motoring along, especially if getting into the crankcase via the oem hose from air box to crankcase vent.

With 29 smoothbores, it is especially critical to assure complete closure between the float needle/seat interface. And IMO this should be the first priority, before fine tuning the float levels.

Good Luck with the smoothies. When properly set up, most folks become believers.

Post edited by: Patton, at: 2007/08/28 21:23

Patton, You wrote: "Some smoothbore folks replace their float bowls with the more "standard" bowls equipped with overflow tubes."

How is this done? The bowl is shaped completely differently than a standard VM bowl. The enrichener brass pickup tube is placed differently and the bowl is sized differently... just curious.

A main reason the 29s will leak gas is that the float levels are set incorrectly. If you can't set the float levels correctly, buy new floats as the old ones have been bent where they have lost their original orientation and setting the float level is meaningless. You COULD build an adpater by buying an extra drain plug and drilling a hole. You could also check to ensure that the screens on the underside of the float seats are in place. ANY bit of grit that gets between needle and seat will cause seating problems for the float needle. Many owners are too cheap to put the filters on when they didn't come on the carbs originally because the little buggers are expensive.

wiredgeorge wrote:

Patton, You wrote: "Some smoothbore folks replace their float bowls with the more "standard" bowls equipped with overflow tubes." How is this done? The bowl is shaped completely differently than a standard VM bowl. The enrichener brass pickup tube is placed differently and the bowl is sized differently... just curious.

A main reason the 29s will leak gas is that the float levels are set incorrectly. If you can't set the float levels correctly, buy new floats as the old ones have been bent where they have lost their original orientation and setting the float level is meaningless. You COULD build an adpater by buying an extra drain plug and drilling a hole. You could also check to ensure that the screens on the underside of the float seats are in place. ANY bit of grit that gets between needle and seat will cause seating problems for the float needle. Many owners are too cheap to put the filters on when they didn't come on the carbs originally because the little buggers are expensive.

Thanks, WG -- I had misinterpreted others' postings about having replaced the usual smoothbore float bowls with the more "standard" bowls (side drain plug and bottom drain nipple), wrongfully thinking it could afford an overflow function to the 29's. So are you saying the standard VM bowl "sized differently" won't fit on the smoothbore carb body (due to different shape, screw hole pattern or whatever), or just that fitting the standard bowl onto 29's won't transfer the overflow function and also loses the enrichener function due to different location of brass pickup tube?

To hogeater -- For checking service fuel level, connection of clear plastic tube to bottom drain hole may be done by first inserting end of the tube through a v-shaped rubber grommet which then push-plugs into the bottom drain hole. It's quick and easy to use and doesn't require screwing and unscrewing anything.

Notwithstanding a perfectly correct float height setting, leakage of fuel past the supposedly closed float needle/seat interface will likely cause too high fuel level resulting in excessively rich mixture.

While screens on the float seats do add protection, a good inline fuel filter is essential IMO.

Good Luck with the 29's!

If the vent tubes are plugged,the float chambers
will overflow.I had my 29s apart 3 times,put in
new needles and seats,before I figured it out.
My friend has them now,17.5 pilots,115 mains,
otherwise stock KZ1000,runs great.

Good point Tim, if the vents are plugged, a vacuum sets up in the float bowl and the floats work strangely... one time they will allow gas to pour out and the next time gas won't be pulled in...

The bowls on the 29s are shaped differently than a regular VM series carb; in fact, they are different than the bowls on the 33s. The main problem is that when the enrichener picks up gas via the brass tube that is press fit into the carb body, the tube hangs down in a different place... the hole in the carb bowl that receives the tube has to line up... the 33 is about 1/8" away from the hole on the 29 bowl... you can use the same gasket but have to cut a bit of material out where the hole is for the other gasket... not sure why they didn't make them the same. If you tried to set a regular bowl on a smoothbore the four screw holes won't line up due to size/shape either...

Keep in mind that the BS family of carbs don't have overflows either... they ALSO use the screens installed on the float seats to keep grit out of the float and seat juncture.

I know what these 29s are worth/selling for on egay. If someone was to offer to trade+cash with a set of ready to run 28s or 33s I'll trade. I'm not so much a speed freak, but I do want a bike to be able to go when I want to turn it loose. I know these are THE carbs to have , but I'd rather be rideing on a KZ1000 than sitting on a set of carbs that has more fuel pouring out of them than the EXXON VALDEZ.

Email me at chuckschoppers@yahoo.com or call 910-324-6916 ask for chuck

I will be running pod filters and 4x2 (baffled) exhaust that stop just under the engine..

Post edited by: HOGEATER, at: 2007/08/30 08:43