Float height question

My float checking tool I bought off eBay arrived today so I pulled the carbs off the bike to check the float levels. I've noticed when my bike is sitting on the kickstand and idling, gas sometimes comes out the overflow of carb #2 and #1, but not as often. This is a picture of the float height level on carb #1.



The pic I took for carb #2 didn't come out, but it was the same level as #1 as shown in the pic. Is this too high?

I found a gas container from a lawnmower and mounted it above the carbs when I was checking them, and had a shutoff valve installed in the fuel line. I made sure the carbs were level each time I checked them, so the measurement should be accurate. I want to get my overflow issues fixed this time around, hence why I bought the tool to check them wet. Thanks for any help!

Hi toadson... a few thoughts.

-1) Neat Fuel Service Level tool! IMHO, level seems high. Is your spec 2.5-4.5 mm below the carb body?

Sorry, image posting problem... see next post for image.

-2) Do you have a vacuum operated Petcock? If yes, I read that they tend to fail such that they do a poor job of holding back fuel. If no, do you put the petcock in the OFF position when engine is off.

-3) Do you have a good guality Inline Fuel Filter? If no, then they are highly recommended to keep realy fine debris/stuff from interfering with the operation of the Float Bowl's Needle Valve operation. If yes, be prepared to clean or replace the needle valve assembly.

Best of success.
Bill

bill_wilcox100 wrote:

-1) Neat Fuel Service Level tool! IMHO, level seems high. Is your spec 2.5-4.5 mm below the carb body?

bill_wilcox100 wrote:

Hi toadson... a few thoughts.

-1) Neat Fuel Service Level tool! IMHO, level seems high. Is your spec 2.5-4.5 mm below the carb body?

Sorry, image posting problem... see next post for image.

-2) Do you have a vacuum operated Petcock? If yes, I read that they tend to fail such that they do a poor job of holding back fuel. If no, do you put the petcock in the OFF position when engine is off.

-3) Do you have a good guality Inline Fuel Filter? If no, then they are highly recommended to keep realy fine debris/stuff from interfering with the operation of the Float Bowl's Needle Valve operation. If yes, be prepared to clean or replace the needle valve assembly.

Best of success.
Bill

I wasn't quite sure what the spec was supposed to be, but now I know. I think it is too high for sure, as it sits about flush with the carb body.

I have a manual petcock thankfully, and I turn it off when the bike is not in use. As for the fuel filter, I do have a good quality one on each fuel inlet.



Thanks for the help!

Was your bike running when you took that picture of your filter? I noticed your fuel petcock was ON.

I took that right after the bike was running, as I was having a fuel leak I was trying to figure out. Gas was shooting out of the vent tube for some reason. I can't quite remember why, but I fixed it and it doesn't leak anymore.

I ordered new intake boots last night, the ones that bolt to the head, as mine were cracking. So as soon as I get those, I'm going to adjust the floats and get them right and put it all back together. I hope it runs how it should once I do that.

Adjusted #1 and #2 floats today. Here's a pic of #1 after adjustment:


Looks much better to me. #2 was the same level, so I hope to have cured my overflow problems!

I recently had to adjust to spec the floats in my Kaw triple because I had the same issue as your original condition -- floats permitting too much fuel to rest in the bowl.

Well, I took care of that by adjusting the floats to spec.

Now it had a knock-on affect of *leaning out* the bike during the 0-to-1/4-open throttle range.

The symptom was poor power until the throttle was open past the 1/4 position (between 1/4 to full open throttle was fine).

I came to learn that the subtle effect of adjusting the floats, which reduced the amount of fuel in the bowls, will affect the low-throttle operation of the carbs because there is not enough vacuum from the motor in the 'pilot jet' range of 0-to-1/4 throttle position to draw gas through the needle jet or mains (duh, in hindsight it shoulda been *easy* to figure out why the bike went lean after the float adjustment).

The pilot circuit is used for low throttle position and if there's a full float bowl, more gas gets sucked into the engine via the pilot jet. But if the bowl is less full, only makes sense that the lower level means less gas will come through the pilot circuit.

My symptom was sputtering off the line until I got to 1/4 throttle.

You might say "but why would setting the float to spec create a LEAN condition for the pilot jet?"

ANSWERS
- I had the stock pilot jets in the carbs
- AND I had pod filters on the carbs

So the pods, providing more air into the carbs as they do, thrived when the floats were allowing too much gas in the float bowl. But when I set the floats to normal, too much air (compared to the stock airbox) was coming in and the stock float height and stock pilot jet were not providing enough gas, so it was lean and ran real sh*tty off the line.

I had already gone to bigger main jets and adjusted the needle clip to provide more gas for the needle jet and main jet parts of the throttle positions of 1/4 open to full open throttle -- I changed those to match the extra air from the pods. But since the floats were set wrong, allowing the float bowl to be too full, I didn't need to change the pilot jets -- UNTIL I discovered the floats being way out of spec. Going to bigger pilots fixed the 'lean off the line' problem after I set the floats to spec.

Just FYI. A subtle problem if you have pods.
BTW, the bike had VM Mikunis like the stock VMs on
our Kz's.