BR carb is screwy...

[Thorpe]

Yes, I have read the thread about jetting and carb tuning. Good article. Here is my problem... I rebuilt the carb on my 250es. Put it all back together, had a chunk of crap come out of the tank, and stick the needle and seat. Cleaned the tank, installed a new petcock and filter, re cleaned the carb and put it back together. Fires up and runs great... For a bit... Its starts and idles great. The machines pulls well if you run it up hard in the revs and shift through each gear... If you want to lug it down in a gear it starts to load up and bog a bit... If you stick it in some deep mud it will do the same, but it you feather it out, it runs awesome in the top end of the revs... Thus leading me to believe the main jet is good... Have my needle set to factory notch and my pilot screw doesnt seem to do much... Sorry for the long story, but I would appreciate anyones input....

[Yamaha_Rules69]

Is the air filter clean and all airways? Did you ever check the plug to see what color it is, and does it have a new plug? Did you check the jet sizes to make sure they were all stock sizes? Sometimes when people rebulid them........

[Thorpe]

New plug, new air filter.... Plug is black.... Jets are new and original size...

[1985BigRed250ES]

needle on the 3rd clip? air/fuel mixture screw set at 2 1/2 turns out?

[lndy650]

Engine RPM isn’t what determines which jet is active so take note what throttle position your at when it bogs not what RPM. its running rich at that throttle position so...
1# pilot Jet = 0 to 1/4 throttle(turn out air screw or smaller pilot jet)
2# needle = 1/4 to 3/4 throttle (drop needle one notch)
3# main Jet = 3/4 to full throttle(smaller main jet)

[Thorpe]

Needle is on the 2nd from the top, and pilot is out 2 turns as per manual...

[Erics350x]

drop the needle clip a notch or two and see how it runs.

[MTS]

Sounds like a really aggressive tire, Too tall of gearing, a worn clutch, or a tired top end, i say this because it apparently runs good without much of a load on the motor,Could be crappy gas too, or some real sticky mud, Im not sure if the BR has a steel needle and brass seat on the floats or not, But they could be worn too,

[Thorpe]

Stock sized tires... Stock gearing, clutch could be worn... Doesnt smoke, and has decent compression. Fresh fuel, not too sticky of mud, alot of water though...

I wil try dropping the needle one more notch (last one) and see what it does....