Motorcycle Repair: Yamaha CT2, wont run right, excessive oil consumption, air leaks

Question
Help me Falcon, I just bought a Yamaha 1972 CT2 175. Only has 750 miles, problem is it lacks power off idle up to 4000rpm and then it screams to red line but will not pull 5th gear. It's also hard starting. When I recieved the bike the pilot jet was completely clogged and would not idle. After cleaning the carb it will now idle but is hard to start and barely pulls off idle. I've checked exhaust for clogs, checked the points, fresh gas, checked compression (120 psi), spark plug (tried a couple), swapped out the carb with one off a 125 ( knowing it would be too lean, made no difference), checked for air leaks, checked float level. Other symptoms are excessive oil consumption ( maybe due to using the throttle a lot to get it to rev out), it's still using the autolube, which seems to be in spec. After running for awhile the spark plug is black and wet. While the carb was being cleaned I noticed the needle was different than the one called out for in my tech sheets, not too sure about the needle jet either, and no number on the main jet. I have ordered a carb kit with jets and will replace all when it arrives , all passage ways in the carb are also clear, also new points and condenser will be installed. Any help would be appreciated.

Scott

Answer
Hi Scott.
 Actually, it sounds like you solved the mystery already.  You mentioned the non-spec needle.  That is likely the culprit.  If it isn't then you could have a bad ring or valveseal.  However, check the needle problem first before tearing deep into the engine.

Good luck.
FALCON