KX Guru Racing

How to adjust your float bowl height.

First and foremost I want to thank Motorrad for giving me this idea and allowing me to share it with all of you.
As with most of the things I take the time to document, Motorrad is either directly involved or gave me the idea's or technical know how to make it happy.
THANK YOU MOTORRAD.

Some will ask, "Why would you want to adjust your carburetor float height?"
I'm glad you asked
The fuel level in a carburetor bowl is extremely important for the correct performance of your carburetor.
Some believe that float bowl height really makes no difference other then for shutting off the fuel when the float bowl gets gets too full or making sure the engine does not get starved for fuel at high throttle positions.
And while that is some of the purposes of the float bowl height it also controls the rate at which fuel travels from the float bowl up to the carburetor.
Many think that the fuel rate is dependent on the vacuum in the throttle bore and the correct jet size.
But the fuel rate is also dependent on the fuel level.
Kawasaki gives a specification of the actual fuel level, measured from the top edge of the float bowl with the carburetor held level as shown below in figure 1.
Warning.
Fuel will be used in this example and chances are you will also have fuel involved.
So what?
Think about this for a minute.... Gasoline is extremely flammable.
Do you smoke? You better not while doing this...
Does your buddy smoke? Tell him to go away...
Is there any open flame or other sources of ignition such as a pilot light? Dude!!!! Get a clue and put them out
Now that we have possible explosions all but eliminated it's time to get to work.

Before you do anything else, clean the exterior of your carb thoroughly to prevent any dirt, sand, or unwanted material from getting inside of your carburetor.

You can go to Kawasaki and buy a tool from them to measure your Float Bowl fuel height but why?
You can easily make your own with a few parts and simple tools.
What we have here is a KX500 float bowl drain plug with a hole drilled in the bottom of it..
This little fitting was from a air nozzle that I bought at Harbor freight for 1.99 which included several other attachments I needed for other projects so it was a real deal Of course you can use many other things for this but it is something I already had.
Now your going to need to solder and JB-Weld the nozzle to the drain plug.
If your going to solder them together you better remove the o-ring from the bottom of the drain plug or you will be looking for another to buy
I tried to solder mine but I don't have the right tools for the job so I JB-Welded mine together and it works great!
If you decide to solder yours, be careful.
A torch is real easy to get carried away with and the aluminum plug will melt extremely fast.
A normal soldering iron does not generate enough even heat to get a good bond.

So let's get around to testing...
1. Turn the fuel valve (Petcock valve) off and remove the carburetor.
Leave the fuel lines hooked up to the carb and the bike.
You will need to be able to hold the carb level.

2. Remove the drain plug from the bottom of the float bowl and install our custom made fuel level tool as shown below.
As you can see, this carburetor isn't hooked up to a bike because I just happen to have this one laying around and didn't have to disconnect mine
It is harder if it is completely removed from the bike.

3. Situate the carburetor so that it is as level as possible.

4. Once the carburetor is as level as you can get it, hold the clear fuel line that is connected to the bottom of your Float Bowl Adjustment tool up as shown below:
5. Open your Fuel Valve (Petcock valve) and note the level of the fuel in the clear fuel line that is connected to the bottom of your Float Bowl Adjustment tool.
As you can see, our level is set too low

So, how do you adjust the float height?
First, remove the screws at the bottom of the bowl.
Next, carefully remove the bowl.
Remember, there are some delicate part in here so be careful not to force anything.

With the bowl off, it should look something like this.
While you have it apart, it would be a good idea to pull the pilot jet and the main jet out and inspect them for any obstructions.
It would also be a good time to really clean your carb out to be sure no dirt got inside while you disassembled it.

Next you need to remove the pin that holds the floats in the carb.
It is located as shown below.
The pin will slide out from either direction.
Also, be careful at this point, take a picture or make notes of what you are looking at so you don't try to install anything backwards
Once you have the pin out, it looks like this.

So, how do you adjust the float height?
See the little tab in the middle of the circle?
You change the float height by bending that little tab.
"CAUTION" it takes very minor bends of that tab to make a large difference in float height so be careful and go slow...
Also note that I have the floats upside down in the pic above.
So which way to you bend the tab to move the floats higher or lower?
With the floats oriented upside down you will move the tab in this direction to lower the fuel height.

To raise the fuel level higher, bend the tab up.
Again, remember that I have the floats upside down.
To test your new setting you need to reassemble the carburetor and set it up level again and use the fuel intake hose to fill the carb up again.
You may need to move the tab several times until you get it just right but be patient and do it until you get it right.

Much much better.
It took me two tries to get it where I wanted it so don't be in a hurry.
A few minutes now will save you heartache later.
Again, special thanks goes to Motorrad for taking the time to send me pics of his tooling and how he did it.
Any questions or suggestions?
Feel free to let me know.
Thanks!
SB

I'm looking to go through this soon. I need the drain plug though. Does anyone have an extra or one I can borrow? Figured I ask before I buy a new on at about $30.00.