250r help

[Lee350x]

Hey i just bought a 1985 250r. It starts easy and idels, but at the top end of the first 4 gears it stops pulling hard and sorta putters, but as soon as its in fifth it goes like hell all through the power band. Its only like 10 degrees here so im thinking that could be part of the problem, but is their any thing else that could be wrong, and what can i do to fix it...thanks for the help

[oldskool83]

might be lean, check your air filter 1st, then clean your carb out for starters.

[harryredtrike]

youll have to tune the carb.make sure the silencer is not clogged up,new plug,airfilter clean.try putting the carb set screws at stock and go from there.