I have a 2004 Cagiva Raptor 125 (2stroke...) I had the engine rebuilt last summer: New piston, new rings, new gaskets, the cylinder was ( i don t know the correct therm) corrected: they added some cast iron on the wall ( it had low compression at wouldn t start). I used only high quality Motul 710 oil.
I did about 2000km last year and i kept it all winter in my heated garage (>10 degrees Celsius), Then it started acting weird: Yesterday i rode it for about 30km. It started normally: i used a bit of choke as it was a cold morning. It ran just fine, i let it rest for 6 hours and then it had a bit of difficulty firing up, but eventually some choke helped it. I rode it for about 3 km, then i let it rest for about 1 hour. I decided to try firing it up to see if it is all ok. It fired up right away, no choke needed. I had something to do for about 30 minutes and then i tried to start it and it wouldn t fire up. I tried some choke, it wouldn t help it. I tried to push start it, it kept stalling, like the engine had very very low compression. Finally... i let it there and thought of another way to go home so i stayed at a friend for 2 hours. I came back to it, tried to start it and it fired up right away, no choke needed, no nothing. I rode it back home (30km) with no problems at all... What could be the problem? I m thinking maybe the carburettor needs some adjusting, but i am not sure.
P.S: excuse my bad english.