250-500cc tmxx38 overflowing

G'day all, took my new wr300 out for a ride with the kids today and noticed fuel running from hose while bike was running and on stand. Not sure if loosing fuel while riding, I have checked float level and that seems to be about 7-8mm... any ideas?

yeah, call JD Jetting and get a Keihnin PWK carb.

mine was doing this too, set the float level slight lower and it stopped

yeah have to start saving for a pwk but need radiator guards,bark busters and bash plate first first...
Troffer88 how far lower 8-9mm?

Save your cash the Tmxx can be made to be better than the Pwk . I lowered it just a little more , just touching the pin

thanx troffer88 ill give it a go..

Nothing wrong with the TMXX. Just set it up right and go!

middle of the day here, at home as the wife and two kids heaving into buckets.... ahhhhh id rather be out getting used to the 300... big difference from my 2000 te410, good to be back on a two stroke!

I just had this problem with my 2006 CR125 I just finished rebuilding. I bought this bike with a catastrophic blown crank, broken cylinder, broken rod failure. I got the bike started and the gas kept pouring out the overlow tube. I can now see how the previous owner blew the motor. Anyway, I tried adjusting the carb floats and had the same result. I then pulled out the needle and seat. The o-ring that goes around the outside of the brass seat was shrunken and hard. It cracked when I tried to remove it. I replaced it with a new o-ring, and no more overflow. Problem solved.

This oring that you guys are talking about that the needle seats on,can I buy one at the hardware store ,I think I just lost mine while clearing the little hole.When I looked through to the main jet with out the bowl on I could see a small spec of dirt so I put a small mech. wire thru the main jet and I think I might have lost the oring on my floor,could,t find it.It almost looked like the oring is still in place down deep into the brass thing,never paid attention to this area of the carb before.

The needle does not seat on an o-ring, it seats on brass. The o-ring I'm referring to goes around the actual brass cylindrical seat insert. You need to remove floats, then remove the screw that holds this part in place, then pull out the brass seat cylinder. You will then see the o-ring I'm referring to. The main jet is not your problem if your carb is overflowing with fuel.

My 09 WR250 float level was set too high out of the crate. I lowered the level in small increments until it would not pee unless the bike was leaned to the left at approximately 45 degrees. The TMX will work great with a little tuning and there is a lot of helpful info here on jetting data and jetting chat threads.

I learned a lot from this post,my seat area was almost fully clogged and when I poked the thin wire thru the mainjet and cleared the hole where the needle sets it was so much more opened that I thought that I lost the oring,I was very wrong.That was defenetly why my 09 wr125 was running out the overflow,problem fixed.Lesson learned is too take off float bowl and look thru the carb where the slide goes and make sure the hole is free of debri where the needle seats.
Thanks for the help.
Dave

I wanna get this right, sorry to sound dumb but am I too push (bend In) the little tab or pull out (bend out) the little tab?

Also, if you need a new needle and seat. Order it from yamaha YZ 125. Husky and everyone else makes you buy the whole kit with float and etc.... guess they are into bundling now for profits.

Yes, try holding the carb at an angle till the tab hits the little preload post on the needle, careful so it doesn't compress. Then set your height.

i had nothing but trouble with the mikuni carb on my NEW 2011 WR300 ! impossible to start hot or cold ! three trips back to the dealer to jet, modify etc ! i was ready to push it off a cliff, then I bought the JD Keihnin pwk from Motosportz ( only $244.00 )and a completely different bike ! starts in 1 maybe 2 kicks cold and 1 kick warm !! pulls from idle to full throttle perfectly and soften that hard hit with out effecting HP.

man tricky little tab to bend, slight bend and still has fuel running out when on the stand. Bike is running good after raising one notch on needle, coffee coloured plug. Really need to get the overflow prob sorted as it would be wasting a fair amount when I get the gate holding duties or when waiting for the slower riders...

It should run out a few inches before the peg touches (approx 45 degree angle) when you lean the bike to the left. If it's running out when on the kickstand the level is too high so keep bending the tab in very small increments until it's correct. If you go too far it will run out of fuel on extended wide open throttle in high gear.