My carb is no where near stock and I just don't know how a little 49cc motor like this will act at sea level? At times do get a clue from the forum but vague as heck? I run a different needle and a different atomizer. My atomizer is leaner and so is my needle with a much larger main jet.. I had to read and read. Last I had to buy parts and simply try them until it was right..for my elevation.
My currant needle is fatter and lets me cruise around at lower rpm with a good air/fuel tune here. When I started out the dang thing was a dragster only in need off taming with no hope of idling around as the carb would load the motor up so bad I had to go back to dragster mode just to blow it out again. ''Black Smoke''
This thing ran terrible and it was mandatory. Now it's flawless!
As for a 12 tooth sprocket I had to get my buddy to catch his baggy jean's paints leg in the engine cog/chain. Was not hard and was the bikes first maiden voyage too. He had the Mapp gas and the silver solder for my throttle cable at the time.
http://motorbicycling.com/showthread.php?t=9010
It took a drill bit to carve the Levis jeans out. Then I had room for the 12 tooth sprocket. lol Funny story and it has never ever even remotely happened to me. I still give him plenty of guff about it in good fun tho. Was late at night and just add drinking.
Poor guy limped for a month he did not put a scratch on the bike tho. Laid it down 30 mph into a turn. Got the peddle. I just don't drink at all used to tho. Truly Terrible habit. IMO
Takes your money and your health. I became allergic to it. Best thing that ever happened to me. It is hot as heck out this time of year. While others are dropping like flies the heat of the sun has no effect on me!!
It knocked a tiny bit of the interior aluminum wall out next to the the mag. Did not hurt anything. Is totally still operational to this day.
So in a nut shell at one time I briefly tried a 12 tooth and it fit! However I did not like it my gear ratio was wrong for my application.. only went about 10 miles with it and never used anything but a 11 then on.
I think a 12 will fit but might need some grooming to make things harmonize? I prolly should for the sake of helping someone? Would have to dig that sprocket back up and hold it against a new motor to say how involved it really is? It runs darn close and can be done.
