'97 cr250 with no top end power

[spoolin7]

Hi all, I just purchased a '97 cr250 from a guy my wife works with. he rode it for a few months, bent the wheel and let it sit for a year because he was too lazy to fix it. i figured it was cheap enough, i'd put a little work into it and get it goin.

i put a brand new wiseco top end kit in it, including the rod bearing and all new gaskets. it starts fine and runs okay, other than not wanting to idle. it feels pretty decent in 1st and 2nd, but anything above that and it just doesn't make much power in the top part of the rpm range. a friend suggested it was the exhaust valve, but i just made sure it was working a few minutes ago.

my guess would be on carb issues, but figured i'd ask around here first

 

[spoolin7]

after doing some reading on how to see if the powervalve is correctly working, someone said if you take the inspection cover off the left side, it should align with L when lower rpm and should align with the H when revved. I revved it pretty high and it would only go about halfway to the H. i'm guessing this could be a problem. any idea on how to adjust it properly from here?

 

[toddb3]

After you installed the new piston and put the cylinder back on did you make sure the lower power-valve rod aligned with the upper rod? I know I'm not using correct terminology but its a common mistake doing the top-end on a CR.

 

[spoolin7]

yes, it lined up. i used a tiny flathead screwdriver to line the pin up with the u-shaped piece, while my friend lowered the cylinder on

 

[spoolin7]

pulled the engine apart earlier. found out that sometime in the past, someone misplace the rod that goes through the valve itself. it was causing the valve to almost completely close the exhaust port and even when it was trying to go up, it was a major blockage. i got that part fixed, but apparently when i was putting it all back together, i didn't line it up right. i assume it was all back together right and put everything back together. started it up, and the line on the alignment thing didn't even move. i took it for a spin anyway. feels a lot better than it did, but i'm gonna have to tear it back apart so i can figure out why it isn't doing anything now. blah

 

[spoolin7]

okay, got it fixed. haven't started it yet, but everything is now moving fluidly. when i put it back together the last time, the rod that ran through the cylinder with the fork at the bottom wouldn't move very freely once everything was back together. turns out, i slightly bent it, and it was pinching the little rod that was supposed to go into it. so that little snag was keeping it from working. i pried it apart just a tad, and now everything's back together and moving freely. the L and H line up from moving everything from the right side and i can watch the valve going up and down. i'm gonna finish putting it all back together tomorrow after work and see if it all works when it's running.

i sure hope so, i have yet to see how good this thing can run