How involved is adjusting the carb float level, and how is it done?

Question

I've come to the conclusion that the float level is a little low in my 85 kawasaki zl900 eliminator. How involved is adjusting the float level? Do I need any special tools? I've heard that it can be very challenging to get the float level right, especially because I wouldnt notice any problem with it except for travelling at high speeds (80mph+) for a few seconds. I am somewhat mechanically inclined, although I have little experience with carburetors. If this is something you think I could possibly do, please give me some instructions. Keep in mind I bought a 2500 dollar bike for the purpose of being able to mess with it a bit without having to worry too much about it.

P.S. enough with the c**p about not going over the speed limit. If you want the definition of wreckless driving try driving on a busy highway while going "the speed limit".

Answer 1

Adjusting the float in a carb is really a bit of guesswork unless you have a bench tester and can actually see the level while the carb is in operation. I seriously doubt you will have the resources to buy a bench tester, so if you think it is too low, you pop the top and measure the height of the float when the bowl is empty. Buy a shop maintenance manual which covers the carb adjustments. They will have a range for the height adjustment for where the float should be when the carb is empty and all it takes is a ruler to measure this height to determine the right place for the float to be. You bend the float arm to get the height within the proper range of height. No special tools that I know of, at least not for the cars and trucks I've worked on. The float adjustment is really a loose adjustment, like within a quarter inch or so, not a couple  1000ths like a spark plug gap or valve clearance. By the way, on what do you base your assumption the float level is too low? Most people assume float level when really it is a weak fuel pump (or a clogged fuel filter) not refilling the bowl fast enough after hard acceleration... you HAVE checked the fuel filter and pump output pressure and verified the flow rate, right? You need the shop maintenance manual with the specs...

Answer 2

Remove the carbs from the bike.

Remove all 4 float bowls.

Tie up 3 floats with rubber bands so you don't make a mess while adjusting one.

Attach a fuel supply.

Hold the carbs over a drain pan.

Turn on the fuel.

Lift the float by hand.

The fuel should stop flowing when the float arm (the metal piece that attaches to the float and the pivot pin) is parallel with  the carb/float bowl mating surface.

Bend the metal tang that touches the float needle to adjust.

Repeat the process on the other 3 carbs.

If you can't get the fuel to stop, the float needle and seat need to be cleaned or replaced.

If you have to replace one, replace all of them (they're cheap enough and you don't want to take your carbs off again in the near future).