How to determine if float height is correct without taking the carb apart?
There is no leaking when on the side stand. It is a brand new bike so seems like it wouldn?t be wrong from the factory, but why are so many floats set incorrectly?

Firstly, we usually set the fuel level a bit lower than Keihin specs due to how the carb sits in the chassis. Helps with splash over fuelling on downhills and haven't had issues with running short on supply during WOT.

Secondly, I don't think they would be checking the level on every carb produced. The tang would be attached the same, but any tolerances are just that. Also, if any bumps to it occur during assembly, or transport (no fuel in it to soften the movement of the floats) then that could move it out of spec a bit.

People have used some cork with a bit of clear tube through it, push it into the drain hole in the base of the bowl and run the tube back up. Fuel on and it'll rise up to it's level. Given that there is no room you'd still have to remove the carb from the bike.

Cheats method is to turn the fuel on, and start leaning the bike over. Take note of when the fuel starts to come out the overflows. It should be around 45degrees or a touch past. Any sooner and the fuel level is too high.

And just to confuse things, high fuel level = low float setting.

+1 to what Jakobi said.

I had three 300's, two 2018 GP's and one 2019 EC in my garage and all started to spill fuel too early when tilted. Dunno if it has been said, Keihin sets all PWK's float levels relatively high.

So first check when fuel is spilled and then, if necessary set float height a tad lower. You need to take the carb off.

I agree with Jakobi and Doc Brown... so even if your bike/carb is brand new it's worth checking the float height before you start trying to get the jetting set correctly.

I bought my first 2 stroke in 2010/11 and had no idea. It was a steep learning curve. Lots of reading, followed by lots of trial and error. Lot's of stopping trail side to make adjustments, and lots of chasing myself in circles.

Since that bike, I have learnt it's easier to simply take the time up front to make sure everything is good before even riding it.

For me that means bike comes apart. Carb gets pulled, fuel height checked, cap screws replaced, throttle cable changed to one with captive ends, slide inspected and manually set while viewing its position through the body. Needle of my choice gets fitted as a baseline with known pilot and main jets.

Head gets measured, squished, modified back into a tighter tolerance at a specific compression ratio.

Straight up a I have removed a lot of variables, and with everything in it's ideal range to start with it's often a couple small adjustments and then many hours riding.

Now my GP300 loses fuel. i install the JD kit and now the carburetor over. Tomorrow will remove the carburetor and check. Does one know the problem?

Probably the float valve has stuck open. Sometimes you can gently hit the outside of the float bowl to make it go back into place. Use the handle of a screwdriver but please be careful.

If that doesn't work, you will have to take the carburetor off and open it up.

Maybe a small piece of dirt in the float valve, so it cannot close properly?

Maybe the float, valve or pin is out of place when you fitted the bowl?

When you open the float bowl it should be easy to see what is causing the problem.

You can connect the fuel pipe and test it before you fit the carb back on the bike.

Good luck, Dave.

I try this but it did not work.

Today i clean the carburettor and set the float level new.