looking through the thread you have said: The plug is wet then later that it is dry? You have adjusted the two carb screws - why? Are they both back in their original positions? You have a weak spark then later a strong spark? Simple tests you can do:- 1. squirt about a 1/2 teaspoon of fuel into the cylinder and replace plug - Turn over and if it fires or tries to then nothing, you have a fuel issue - Skip to 4. 2. With the plug out, ignition on, check for spark as you gently push the bike forward in 2nd gear. Stop as soon as you see the spark and (using a plastic drinking straw, check that the piston is at Top Dead Centre (TDC) or just about there. {Rough Timing Check}. 3. With plug in, turn over with your hand over the exhaust - You should feel the pressure pulse from the engine. 4. Ensure plug is dry and re-fit. Turn over and check plug. If not wet, then no fuel getting into cylinder - check all lines, filters, etc. 5. If plug wet, then either contaminated fuel or incorrect mixture or timing out. Good luck!