Adjusting Fule Level on 29mm's

So how does one go about adjusting the float levels on the 29mm smooth bores?

badrhino wrote: So how does one go about adjusting the float levels on the 29mm smooth bores?

Fuel level is of course the critical factor, not float height.

Measured "float height" is a stab toward achieving the proper fuel level, but should wind up being whatever is required to attain the correct fuel level.




Could use clear tube method to determine fuel level inside smoothbore float bowls.
Without a side located drain screw in smoothbore float bowls, may collect fuel from hole at bottom of bowl.

Some folks adapt a spare 17mm bolt plug by drilling and fitting a nipple to attach the clear tube.

I just use a cone shape rubber plug pressed into the drain, with a hole through the rubber plug, and the clear tube fitted snugly inside the rubber plug hole.

Then hold the rubber plug in position during the measurement.

Others report a successful smoothbore clear tube rig by cutting an inch of 3/8" reinforced fuel line that fits snugly in the bowl drain threads with the clear 1/4" line pushed inside the 3/8" hose.

Some minimal leakage won't affect the results, as fuel volume entering the bowl exceeds any leakage.

Good Fortune!

If ya just gotta have the special tool --

www.z1enterprises.com/detail.aspx?ID=4341

Good Fortune!

and if ur smart enough to find the plumbing section at Lowes/Home Depot
kzrider.com/forum/21-tools/385849-dual-c...oat-level-tool-setup

Oh, I see.... I was wondering how to do it on the 29mm since it had the large nut on the bottom of the bowls.
Don't most other carbs have a nippled outlet for doing this?

yea the example i showed was for vm 28's which have the same size drain,, the white plastic pieces are oversize and I filed the threads down and screwed them in, the rest is just tubing, tie wrap and a bolt for a drain plug, cost $ 10, if u need help let me know

badrhino wrote: Oh, I see.... I was wondering how to do it on the 29mm since it had the large nut on the bottom of the bowls.
Don't most other carbs have a nippled outlet for doing this?

yea ur right
and I was just kiddin about the being smart enough crap :woohoo:

This probably gets pretty messy when you have to do each carb separately and loose the gas at first and then after setting the float height.

You can do the same thing on the carbs with the small drain screws. Just go to the hardware store & buy a plastic tee close to the right size. Remove the metal screw and cross thread the plastic tee in the carb, It will seal & wont hurt the metal treads. Attach a length of tubing & run it up between the carbs & youre done.

badrhino wrote: This probably gets pretty messy when you have to do each carb separately and loose the gas at first and then after setting the float height.

And smelly :pinch: , especially if working inside or in an enclosed area.

With a carb having a known correct fuel level, could experiment with the same carb by repeating the clear tube measurement using common inexpensive household rubbing alcohol (which imo has a much more pleasant aroma than gasoline) and comparing the resulting fuel levels between alcohol and gasoline, which would demonstrate the comparative buoyancy between the two different fluids. Rubbing alcohol will result in either a slightly higher or lower observed fluid level inside the clear tube.

Assign a scientifically appropriate name such as "correct level using alcohol," which may then be used to determine and correctly set the floats in the other carbs when using alcohol.

And don't forget to wear a genuine Marty Feldman protective white laboratory coat.

Good Fortune!

When performing the clear tube test, it's usually only necessary to insert and tighten just one of the four bowl screws.

This saves some time involved in removing and replacing the bowls incident to making the float tab adjustments.

Good Fortune!

hi i have a 1984 zn 750 ltd it starts realy bad cold
i've cleaned the carbs
but i dont have a book for the float adjustments
someone told me to check maybe the valve clerance
the motor hase 71000km on it
it's a canaddian bike some place it looks like the us and canadian ltd were diferent
can anyone help me ?