Having trouble rebuilding old 1990 CR250

[Wyld Bill]

This past summer/fall I have been trying to rebuild a CR250 motor. Basically everything was junk. I put new bearings, seals, & gaskets in the gear case. I put a entire new clutch in it.etc,..etc... The latest problems I have had are
1. Jug going on studs hard.
When I put my jug on the gear/crank case it went on hard & I ended up pounding it on with a plastic hammer. It seemed like the studs in the case were crooked or something. Could this be or is it that the space between the cases was too wide because I used a gasket AND gasket sealer?

2. The HPP. problems
Before I put my jug on I put on my side case (the one with the water pump in it) As I put the case on I fed the spindle for the HPP rod into the slot in the detent bolt. Once the case was all the way on & bolted down the shaft up through the cases was not hooked into anything. I tired turning the detent bolt CCW & tried getting it to hook onto the cam spindle. It didn't seem to want to "lock in" So I pulled the side case back off & fed things back together as I got the cases close to touching together I looked in at the detent bolt slot & the cam spindle. The detent bolt looked like it was in too far & the spindle cam was going to just fall out as the case was bolted down tight. Sure enough I think that is exactly what is happening. Anybody know what could be wrong? Anyone even know what the heck I'm talking about? I put the jug on & the HPP cam & the rack got bound up at first but after reaching inthe slot with a tiny screwdriver I think I got things freed up. When I turn the screw on the pinion shaft for the left valve I know the rack & cam are in sync because I can feel it moving against the detent bolt. I don't know if I should just finish putting the motor together & rev it up & try to get things to lock in that way. :bang:

 

[Wyld Bill]

Oh come on guys I need hlep with this. :(

 

[Morvo]

Not sure about the second problem you got mate, don't quite understand, I take it that's for your 4-stroke since you're on about cams and stuff. The first problem you said about sounds dodgy, you shouldn't have to pound the cylinder onto the crankcase. You do use a piston con rod holding tool to put the piston into the cylinder yeh? The rings can only go on one way around the piston, the edges should sit against the notchs on the piston. It can be a bit fiddly putting the rings inside the cylinder but once they're both in you should be able to depress the kickstart lever to move the piston into the cylinder. Then you can slide the cylinder onto the studs, maybe with a gentle tap going around it to seat it flush with the crankcase surface.

 

[Wyld Bill]

Not sure about the second problem you got mate, don't quite understand, I take it that's for your 4-stroke since you're on about cams and stuff. The first problem you said about sounds dodgy, you shouldn't have to pound the cylinder onto the crankcase. You do use a piston con rod holding tool to put the piston into the cylinder yeh? The rings can only go on one way around the piston, the edges should sit against the notchs on the piston. It can be a bit fiddly putting the rings inside the cylinder but once they're both in you should be able to depress the kickstart lever to move the piston into the cylinder. Then you can slide the cylinder onto the studs, maybe with a gentle tap going around it to seat it flush with the crankcase surface.

Yeah the piston & rings went infine but I had to beat on the cylendar pretty hard with a plastic hammer to get it down over the studs. Once it was seated down I noticed that the studs had aluminum inbeded in the threads from pressing up against the side of the holes in the cylendar so hard. Not good :|

 

[SoFlo]

So you are saying that because you used gasket and goop on the cases when mating them, that they might be too far apart, and the cylinder went on hard since the studs are futher apart now? If you got it on, I don't see how that would affect the topend's performance, but maybe in the lowerend, things might not fit right, since it's just a tad wider? I don't know myself, never have worked on the lower end like this, just guessing around. Hope someone who knows their stuff comes on here.

 

[ellandoh]

check this link

scroll down to hondda hpp

 

[Wyld Bill]

check this link

scroll down to hondda hpp

Read that about 25 times. I don't understand why MINE isn't engaging like it says it should. :bang: