I posted this under the suzuki topic as well

been doing some resarch about the last post I put up about a lt250 (I think its a 89) not having a powerband like most 2 strokes, there is no surge in it. I believe now that it is the powervalve or exhaust valve, they might be the same thing I dunno? I think it is sticking, how do you fix this, do you have to tear the entire engine down? need some help, thankx.

the bike has a new 38mm carb, paul turner headpipe with fmf exhaust, bored .20 over
its a friends bike and we have gone throught the engine rebuilding it more than once, any sugesstions on the exhaust valve??

91 250(soon 2 b 350)X
86 ATC250R Fast...

 

I don't have any experience with that perticular bike, but some 2 strokes just don't have that "light switch" type power band. You do not have to disassemble the entire engine to get to the power valve. I don't think. The last experience I had with a fulty power valve was on a KDX 200. It was simply worn out and would not rotate properly. It should be mounted on one side or the other of the jug, towards the top. Usually under a plate of some sort.
I would ask around though, you may have too high of expectations for the power band. I used to have a TS 185 Suzuki and it had a very mild power band. You could feel it pulling, but not like a YZ or an RM where it snaps.