Odd that you have no bottom end power after all you did. I have always found the Keihin to make more torque than the Mikuni. With putty in the intake, it should make a little more torque. a 45 pilot sounds a little lean on a 125 but just a guess. Interesting ... more »

I can think of two brands that are "roached" at 35 hrs and they aren't orange or white. These two brands feature fasteners made from coat hanger metal and strip easily. Haha

That's good oil and you can mix in a smoker transmission no problem.

Normal. Just clean and inspect everything per the manual. The HPP powervalve system is pretty complex to service and rebuild but not too bad if you follow the steps.

The powervalve drum on the left side (under the cap on left hand side) should rotate 90 degrees from full closed to full open. There is an "L" and "H" mark on the side of the cylinder. Is your PV not opening or not closing completely?

The idle circuit on those carbs was set by turning the choke know counterclockwise to increase the idle and clockwise to decrease idle speed. I believe the stock setting is between 18-25 clicks out from fully seated but don't quote me. The trick on those ... more »

I ran an '01 RM 250 with a plastic impeller that melted off and debonded. The cooling system was basically functioning as a convection cooling system. Haha. I kept wondering why she got hot and puked coolant with no change to jetting or compression. ... more »

Either someone didn't put the impeller back in or it broke off and degraded. Either way, you need an impeller.

Damn it! that was my second guess (last gen 125). Awesome bike!

Newmann!!! Could it be a super low hour '02 CR250?????

I'd think 14/51 or 14/52 would be a good starting point. You'll be in 1st a few time and have to pass over neutral which isn't ideal, but 2/3rd will a bit more normal.

I put a vertex "B" piston in a an '02 CR250 "B" cylinder and man, it felt tight. I measured everything and found the piston to be about .0005" larger than the measurement as well. It almost bound up in the cylinder as I test fit it in the cylinder (without) ... more »

When I bench shift a YZ 250 motor, I put shift star drum on (make sure the locating pin is alligmed with the groove in the shift star and torque to spec (22ft-lbs) and I do not put the detent spring and arm on yet so I can feel the shiftforks move. You ... more »

run at least 50:50 race fuel at 10.8cc volume. Look for any signs of detonation and bump up % of race fuel if necessary. Race fuel is expensive but so is melting down a perfectly good top end.

the powervalve has a massive effect on jetting. It goes with out saying that once you get the PV fully operational, the jetting will change.

I have not tested the Fat Bar but most feedback I've seen is that the PT EVO has the most flex/compliance.

Your going to need to replace the seat. I would do the intakes as a pair and get new valves. Ouch.

Pro Taper Evo "Stock Husqvarna" bend is very close. I measured them against the stock Neken bars on my 350 and they were almost identical.

Sweet Jesus! That rocker arm and cam are toasty! My only suspicion would be: -clogged cam/rocker oil jet and lack of lube -overly tight intake valves which basically means the rocker arm was riding on the entire cam lobe and never getting a chance to ... more »