Another Float Question

[ZKDX]

I've read quite a few threads about how you should check float height when you have fuel running out of vent lines while parked. Well i followed my manual step-by-step for checking my float height...used a tube connected to my drain, held beside carb visually check height of fuel in tube---manual says .08 from top of bowl to fuel height, well you can easily get anything you want just from moving bike, carb, or tube a little......anyway my question is: Is there a good article or thread telling the specifics of setting your float height.. i was going to just bend my tang down, but i have no idea how much, I know there must be an accurate way of knowing how much to bend the tang

 

[BRush]

Originally posted by ZKDX
, well you can easily get anything you want just from moving bike, carb, or tube a little......anyway my

You have to remove the carb from the bike to accurately check the float. The carb needs to in a true vertical position. There are a couple of different ways to do it. The best way is with the graduated tube that screws into bottom of the float bowel. I bought the Kawasaki one and it was not horribly expensive (~ USD $24) That allows you to actually confirm the level is correct, but it requires more work and is more dangerous than the alternate methods because you need to actually run fuel into the carb (and gas is flammable, so care must be taken) when the carb is off the bike. There are a couple of ways to do this. One is to attach a longer tube to your gas tank petcock and get a friend to hold the carb, while you deal with the measurement tube. That uses your bike's tank as the source of the fuel. I ended up making a simple test stand, using a plastic shampoo bottle as a small gas tank and a brass petcock I bought at Home Depot to control flow to the carb. The bottle was duct taped to a short 2x4 and a small bracket to rest the carb on added slightly below.

Bending the tang is a trial and error thing: Bend the tang, put the float bowel back together, check the level, repeat as required. Not that I should have to say it, but let's remember that gasoline is extremely flammable, so make sure the area you’re working in a well ventilated area and that there are no sources of ignition (A basement with hot water heaters and furnaces is an extremely poor place for this).

The other methods involve measuring the float position and are less accurate, but generally quicker. The service manual outlines one procedure and a couple others can be found here:

http://justkdx.dirtrider.net/floatlevel.html

 

[MX175]

I've done this too. I used a stand or small Dremel D-Vise to hold the carb and just used a length of fuel line (about 2 feet) and a funnel as a source of fuel. I think I used about a pint and reused it for testing several times. The time consuming part was screwing and unscrewing the float bowl. I tried using rubberbands, but the gas ate through them real quick. I'd suggest trying something like a C-clamp, but you have to be careful and get the bowl seated correctly and not overtighten the clamp. Moving the tang is very touchy. It seemed like when I could tell that I moved the tang, it was too much. when I pressed on it, but couldn't tell if I changed its position, that was about right. I was at about .01" when I started and I got it to .09" and decided that was close enough.

Yes, it is important to use gasoline, because the density of the fuel will affect the position of the float. If you were to use water, because it is denser, I think you would get a lower than true fluid level. Yes, be very careful with gasoline. Not only flames, but sparks can set it off. Let us know how you make out. --No, I don't want to hear about your necking techniques....

Mark
'80 KDX175
'81 XS850
"85 KDX200

 

[ZKDX]

thanks for the tips fellas, i will try here in a day or three when i get a chance to wrench again.

 

[canyncarvr]

An input from the simple minded side...

I'm sure the 'correct way' is ....well...correct and all. I fail to see the purpose of it all though.

Why not 'just' adjust the tang so the mold line of the float is 'about' 1mm under parallel when the tang 'just' touches the float needle pin?

Takes you a couple of minutes. No fuel used at all. It works. No deleterious consequences.

...simple.......

BTW...bending the tang DOWN is the wrong direction if you want to lower the fuel level in the bowl. Bending it down will allow the floats to go higher before the fuel is shut off at the needle.

..assuming you aren't looking at the carb upside down....;)

 

[ZKDX]

my floats are not attached to the tang---the floats rides on two rods mounted in the carb bowl---so i don't think i can do it your way canyn---although that would def. be the easiest

 

[Jim Crenca]

Man you guys have way too much time on your hands.
IMO, a fresh inlet jet is much more critical than minutia in measurement so one might start there.
I machinist scale has worked well for me and the numbers in the manual seem about right.
You can also blow through the fuel line fitting while moving the float to get a sense of when in the float stroke the seal actual happens.

BTW, I've worked with an automotive carb rebuild shop that flow tests each carb prior to shipment. They use a non-flamable liquid with a specific gravity very close to gasoline (of course race gas is different than pump if you feel realy anal retentive). I'm told that mineral spirits or kerosene is a reasonably close alternative if you choose to go the chemistry set route. :thumb:

 

[canyncarvr]

zkdx:
Regardless of how the floats are mounted to or connected to the tang it will still work.

There may be no such mold line on your floats......which would make it harder to judge. Is yours an 'H' model?

In any case (read the simple minded part above....) I don't read anything you last posted that would preclude setting float level by sight as I indicated.

Most floats I've seen have a shape to them that, lo and behold, appear 'level' when set correctly.

I have seen some mikuni floats that are just plain ROUND...and you can't tell diddle from looking at them.

Hope you get it sorted out to your satisfaction. ;)

 

[ZKDX]

my mikuni floats are perfectly round and float up and down two rods, so i don't see how they could be anything but perfectly level. I guess i will just try to adjust the tang put it back together, turn fuel on and stand back.

 

[canyncarvr]

Well thar' 'ya go. It's the roundness of the buggers that makes 'em a pita. That and now I understand the 'ride on..rods' part.

Consider anything I've said regarding your situation to be a waste of time.

:(


Must be time for a new bike!!

 

[shr]

ZKDX,

The two float arms should be parallel to the carb body when the needle valve is closed.

Do not bent the arms only the tab that touches the float valve.

 

[JasonWho]

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[ZKDX]

jasonwho: i'm checking my float height because over the fuel dripping from my vent lines. What all have you checked since you tipped yours over?