just completed my first gasser topend.a couple of minor points-
1.leave the coolant fitting in place on top of head,remove rad hoses via hoseclips instead.i thought i could get away with lifting hoses/fitting in one piece up out of the way.wrong,i destroyed the coolant gasket removing and its not included in the gasket kit(everything else is)so had to cut a fresh one.and i had to remove hoses anyway!
2.The fibre oring on the coolant drain screw does not respond well to overtorqueing!
3.if you source piston kit and topend bearing seperately,check the new bearing matches the old.the correct part is cr250,yz250 crossover.the one i was supplied was 2/3mm narrower.Tempted as i was to use it...i didnt!
4.When it comes time to drop barrel back on studs,with piston and rings just in,the barrel fouls on the chassis rail if you try and keep it "square",instead lead with the rear studs,as it drops,roll forward and into"square"position.also be careful not to bend pv rod at this stage.
5.remove exhaust spigot,its easier with it off,star drive screw type
6.Dont forget a little 2t oil on the smallend bearing,piston skirts,and cylinder liner prior to reassembly
7.Be really careful not to pull up the powervalve rod at anytime,trickiest time is when reassembling actuator plate as the tightening torque on the screw tries to rotate whole assembly.restrict plate from turning,i wedged a tube socket in the left side of actuator plate(fiddly holding socket and actuator plate aligned,whilst also tightening screw)
8.Leave a little freeplay between washer and powervalve rod,needs to move freely.
9.Points 7,and 8 will make sense when you've got the rh pv cover off!
10.Leave shrouds on tank and have a hook from ceiling ready to "hang"tank from front bolthole.means you dont have to empty tank or mess with screws into plastic tank removing shrouds
