1992 YZ 125 Jetting , pipes and motor upgrade info wanted .....

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2/12/2019 12:47 PM

Just got my self a super clean low hours original 92 yz125 and years of wanting one, totally stock with boyesen reeds, from all accounts they weren’t the quickest of the bunch back in the day so can anyone shed some light on what’s goin to be the best way to liven the old girl up with out braking the bank or stripping the motor ?? I see PC still do a pipe .....? Jetting is stock at the mo 330 main std needle clip 3 and 20 pilot ....

Any help etc would be ace



2/12/2019 1:58 PM

The problem was the ports where mismatched from stock. Like the power valve didn't match the exhaust port well. The only real way to fix it was to have it ported to clean up the flaws. Along with better reed pedals and a pipe. The biggest flaw was the porting.