UPDATE: latest on my 100cc BBK install

[scootx]

just thought i would kinda start over a new thread because when i first started on this website, my posts were everywhere and i was a little nervous, but anyway, my very first scooter ive ever had i bought about 3 months ago at a hardware shop and after about 3 months i wanted to go faster with more power, plus i was also very curious about the engine and wanted to know how it worked.. ive been building racing drones for awhile now and i just love to work on things and figure out how they ride or fly, lol, sooo i installed a big bore kit on my 50cc scooter, engine 139qmb, uhhh i think the short case version.. but anyway, i did it and with the help of the youtube video i got it all back together.. that was a very long but fun project.. i learned alot..  but afterwards, i had so many issues, first an oil drip, (i think i have fixed) and oil in the air filter, (which has ALMOST stopped) I think i NOW have a problem overheating after about 20 minutes of riding.. i DID replace the carberator and the new one has an 85 jet.. the engine will now run a little better and believe it or not it was when i replaced the stock carb with a brand new racing carb, the oil leaks slowed.. although now my main question is this: i can get it to idle at very low rpms, but i think i achieved this by adjusting the little screw on the carb.. NOT the idle screw but the flat head style screw on the SIDE of the carb.. pilot jet? im just guessing.. its on the outside.. i like opened it 3 turns and then adjusted the idle screw.. is this correct ? thanks  

[milly]

Good to hear things are improving. Screw on side is known as the mixture screw which controls fuel/air mix for part throttle usually set approx one and a half to two turns out from fully seated (screwed in fully lightly then back off the turn and a half. Tickover speed is controlled by the screw at the top that can be seen when looking through in flap at bottom of seat bucket when installed. That has no effect on fuel/air mix only increases or lower revs by moving throttle slide/ butterfly up and down. Hopefully that made sense am tired 😫

[GrumpyUnk]

Overheating could be caused by low airflow from the blower on the other end of the crankshaft. If the shrouding is not assembled properly, air from the blower will leak out and not pass over the 'hot spots' of the endine(cylinder head/cylinder for the most part). There is supposed to be a gasket around the spark plug boot to seal agaionst the shrouding. If missing, air can escape there, and not do any good cooling. If the two shroud halves are not assembled together, air can also leak out. The blower surround should also be tight to the other two pieces of the shroud plastic. If loose, or missing screws, best to get that sealed up as best you can. When you took it apart, was there a rubber gasket around the cylinder head? If so, it should have been kept in place upon re-assembly. It helps insure the air flows around the cooling fins rather than out past the sides of the rocker cover.
tom