Hi all, Sorry for the long winded post. I purchased my WR second hand. The previous owner said that the valves clearances had been recently checked and were within spec. After around 400Ks riding i found that it was getting harder to start and was beginning to stall when the revs got low. I checked the clearances and found that the 2 exhaust valves were out of spec so i re-shimmed and was back in business, the bike was running great again. After approx 500 Ks riding since the re-shim again it was having similar problems. When cold it starts and idles fine but when warmed up it wants to stall. I rechecked the valve clearances and are still within spec, I have removed and cleaned out the carb, new spark plug, i always keep the air filter clean and not that it should matter but i put new oil and filter in. I have found that when the bike stalls it nearly always stops rotation at TDC so the Estart cant turn it over and the kick start is locked up. I can free it up by rocking it in gear. I'm definitely no expert but i think it may be a sticking valve which is why the engine always stops in the same position. I'm going to pull the head off and take a look. Should i just replace all valves? The bike has done around 6000Ks. Any help or input would be greatly appreciated.