Checking Float Level 06 WR250


I have had a rich jetting condition for a while now and some plug fouling

But I am not sure what the float level hight is suppose to be or how to check it properly

With the carby upside down the float seam is level with the body of the carb...

Is this right the procedure and the float level?

I am running the following jetting:

Slide#4. PJ:27.5. MJ:390. Needle:60 3rd clip. Air Screw: 2 turns out

1500' 26-30Deg C. Plug NGK: BR7ES


The float seam should be level with the carb. body, yes, but if you hold the carb upside down it could be compressing the spring in the valve. You should only lean the carb over enough to close the valve, not enough for the weight of the floats to compress the little pin on the valve.

If the spring is compressing and its still level, that would make it leaner so float level doesn't sound like your problem.

In my experience fouling plugs has always been a rich pilot, and your fuel screw being at 2 turns out also suggest your pilot is rich (although I've never had much luck jetting by what the fuel screw says). The difference in fouling in less than 10 miles and never fouling can be as little as one pilot.

Even though its a colder plug a BR8EG doesn't foul as easily as a BR7ES because it has a thin electrode that is easier to fire (based on actual experience). That would only prolong the fouling though so it doesn't matter, the cure is in the jetting.

The thing comes stock with a 10 or 15 pilot so you can test leaner pilots, although I wouldn't go as lean as stock.

I posted some pilot tuning info (to make sure you don't go too lean) in the Jetting Help? thread.


Uhhh.... just looked at the "Jetting Help" thread and obviously you already knew about it. :applause:

Anyway, I think you should try a 25 pilot if your still fouling plugs with the 27.5 and see if it helps.



I posted in the jetting section as well....

The air screw like you say doesent do much that I can tell less than 1 turn in and it stalls more than 1.5 turns out end I cant tell the differance untill it falls out!!LOL

The manual says stock PJ is 35!!

It had a #3 slide in and I changed it to a #4 which is better leaner..

The jetting chart in the crappy hand book never goes lower than a 30 PJ no matter how high or hot it is....

I will order a 25 and try it this weekend....

This idle jet stuff is very confusing,a mate was told that anything smaller than a 30 was dangoursly lean and yet as stated in a previous post standard is

a 10 or 15,my mate runs a 32.5 and is mostly not fowling plugs,2 or 3 rides no dramas and then he will fowl one,BTW this is at sea level and up to 1000ft,this is on an 02 WR 250

I am running a #20 pilot in my WR250 with the #3 slide and a Power Now. It runs even a little rich at my average altitude of 6-7000'. At my base altitude of 4000' and cool temps it is perfect. I would try the #25 pilot. Just be cautious initially.


Stock my 07 came with a 15 pilot, 61 needle, #3 slide but i think that jetting is based on having the throttle stop left in.

I took the stop out and put the 60 needle in, the 35 pilot and put a #4 slide in seems to run fine, never fowled a plug.

In the summer i will run a 30 pilot and play with the needle, some guys up country 2500 to 3000ft are running 27.5 pilots

From Mukuni rep....check float with carb at 45 degress not to compress spring and a TMX38-2, or -5 that is 6-7mm height where the other TMX/TMS carbs are 18-22mm height from base of carb.

My 02 WR250 was fouling plugs like crazy...went down to 25 pilot with no real effect & had to go out 2.5-3 turns. Checked my float...was 14mm....adjusted to 20mm and now I have gone back to a 30 pilot with 1.5 turns out. Float height makes a difference--plus no overflow while bike is sitting which was a pain.

From Mukuni rep....check float with carb at 45 degress not to compress spring and a TMX38-2, or -5 that is 6-7mm height where the other TMX/TMS carbs are 18-22mm height from base of carb.

Ok, so the TMX on a Husky, the height is 18-22mm?

Is that from base of carb to the top of float?


Thanks photos helped. I did the float level with the carby flat I will re-do it with 45 angle and measure it... !!Thanks.....



just got back from a ride. And no fouled plugs, the plug is nice and brown, and the bike rips!!! My float level was way out......

I have a FMF gnarly pipe that I would like to put on, would I have to change jetting? Generally would you go richer or leaner with jetting for an aftermarket pipe??

#4 slide PJ:27.5 Main:390 Needle:60 3rd clip

Thanks L

Am hoping you have a typo moment there in your post with a 290 main but meant a 390 cause That is WAAAAAYYYYY lean my friend. Hoping it was the float and a smaller pilot that fixed it. The TMX is lateley been a victim of poor quality control and float settings have been bad from the factory.



Was a Typo 390 main, and that bike was set up by me dealer he did not check the float level,they mainly sell Husqvarna power equipment and are looking for a bike mechanic so I will let them off....


Good to hear it! Now remember, you are your own mechanic until you find one so, to use a race day expression when something breaks, "who's your mechanic?" often turns to a emabarrassing moment for all of us when asked by others. We are here to help so until you find a mechanic, ride and stay in touch!


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