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This was basket case, 1st resto, built rider, no where near Harm's beautys. But had to chime in cause their rare. Has 2000 front end adapted, New spare top end w/ pwr valve, lots of spares, and is for sale. I cant ride anymore. Harm they are beautiful.

Many seized due to worn drum & stopper, allowing the drum to over rotate into the exhaust port, and impacting the piston.Definitely have to relieve the drum if you allow for more rotation. I was impressed with the simplicity of the design when I rebuilt my 92 250. One of my riding buddies loved his 89 & 91 Yz125”s, he was not big on maintenance and the bikes lasted a long time….

I have a 98 YZ250 the last of the drum power valve 250s. I had Noleen port the cylinder in 99 for motocross and the biggest changes I saw were they modified the stops on the drum for more closed and open and they shaped it to match. That bike still to this day had the broad spread of power I've ridden. Pulled way down low and ran hard all the way till it ran out of RPM. Now if I could only find a matching Noleen pipe for it (mine I smashed racing hare scrambles). My 86 YZ250 has...

My friends had those bikes back then brand new. None of them were prefect stock. I have a 92 Yamaha 😁 I have acquired most of the parts

It was slow came from those who A never rode one B never bothered to set it up properly. They did come factory with some minor issues that hindered performance. Mostly the power valve stop was machined wrong and it didn't let it open fully. Weak reed petals. Bad squish clearance stock. So places like dgy would do some mild engine work and it was much better. It had decent bottom good mid okay top. Those gen ypvs drum engines didn't rev out high. The last bit was media bias at the time still hung up on the cr125's ability...

Doug Henry holeshot a moto on a DGY 91 yz125 at Millville. The race is on yt.

damn that is nice!