So i bought a used 04 rm65 last year. Not running. I tore down sent cylinder off to langcort. They sized to numra kit i bought. I put in wiseco crank and seal kit. Bought new head as previouse had dremal marks in it. Put it together and ran it. Never started easy, never did compression test, figuredit was good. This year started racing, tested compression to see where it was at. 115. Multiple testers. Bought exact same piston kit as last year, 44.47. Put in had same 115 compression. Note i live in colorado about 5000 feet. Bike runs fine, just have to kick 5 6 times to get low idle for 30 sec then can get to rev up and go. Manual says 109 to 170 is spec. I thought compression loss might be due to altitude. 3% per 1000 feet. But talked to local others and say it sould have solid 135 to 140. Took apart again, measured bore its at what lancourt finished it at. Ring in gap good. Cylinder very clean. Pressure test engine, holds pressure. My only thought now is could i have the wrong cylinder on this bike. It was used and had been apart before. I even put high compression gasket kit in it and got 118. Wet test and only get 5 pounds more. Not sure what else to check. Thanks