150cc running problem

[yardog]

Replace carburetor with new. Still have same problem. Cdi or coil? Could there be internal engine problem other than valve adjustment as I have adjusted and rechecked. Valves are ticking. It revs to high rpm without any hesitation. A/F mixture screw out about 2 round, can not get low enough idle to fine tune adjustment.

[yardog]

I notice rear tire does not turn unless scooter is over 2000 rpm.

[Lefty]

Yarddog,
You say that turning the Fuel Ratio mixture screw in either direction DOES NOTHING. What that tells is that either the PILOT JET and or ITS PASSAGE are clogged. You are basically keeping it going by raising the IDLE using the IDLE SPEED screw.

So take the carb off and make sure you can see daylight through the PILOT JET then Stick the Carb Cleaner in the PILOT JET hole and SPRAY the SPRAY SHOULD COME out by the BUTTERFLY. You can hold the butterfly open and you will see about 4 tiny PILOT JET FUEL OUTLETS spray must come out of those holes. If it doesn't you can take tiny wire or tiny needle and poke the holes a little and spray and poke until spray does come out.

The RPMS must CHANGE with turning the fuel ratio in either direction at some point turning it CLOCKWISE it may kill your motor and turning to far counterclockwise will make it start sputtering or dieing from to much fuel.

You want to get the highest IDLE(RPMS) when adjusting the Fuel Ratio Mixture. And like I said if turning it either direction does nothing it is clogged.
Lefty

[DW]

Just my 2cents. Had the same problem on my fiji the other day, turned out to be the snorkel had come loose from the bottom of the airbox under the seat. Easy fix but can be hard to spot.

[50cc]

Try dropping the needle (raising the clip) all the way, then stretch the spring a bit. I know it sounds weird, but that's how I fixed the very same iding issue on my 50cc.