I'm not sure which style idle jet your carb has, but let's assume it is the standard type. screw it in until it stops and then back it out 2 1/2 turns. Same with the high speed needle. If the idle jet does't tighten after a few turns, the screw it out until it stops and then screw it in until the end is flush with the end of the throttle barrel. You engine should sort of run at this point.

Start it and while leaving the glow starter on, start turning in the high speed needle, slowly until the engine reaches maximum rpm and then starts to fall off. Back the high speed of by a 1/4 turn. If the engine will now run without the glow starter on it, bring it up to full throttle, slowly and re-adjust the high speed valve. Once you have it adjusted, then go to idle, as slow as you can with the engine still running. Now slowly tighten the idle screw ( use a lot of caution here as you are very near the prop - a long thin screwdrive that put your hands out of range of the prop is needed. Again caution ) for maximum RPM. Cut the throttle back again until it just keeps running and adjust the idle again. You should be down to 2500 rpm or less. A tach is really needed but you can do it by ear.

Now go back to full throttle and adjust the high speed valve again. Back to the idle one more time. You should be very close at this point. Now we work on the transistion from idle to high speed. With the engine warmed up, one or tw full minutes at mid range, take the engine down to full idle and let it set for about 15 seconds the jam full throttle.

If it imediatly dies, the idle is set to lean, turn it out 1/8 turn and try again. You want the engine to bark to life as soon as you jam the throttle.

If it sputters and stumbles, the idle is to rich, turn it in by 1/8 turn. Try agin and adjust until it responds well.

When properally adjusted, the engine will jump to high speed with no sputtering or stalling and when you jam it to idle, it will drop down to idle without stalling.

The key to tuning the carb is to do it in small steps. 1/8 turn maximum at a time for the idle jet and one click at a time on the high speed needle. It takes a bit of time for the engine get the new mix, especially at idle. When you are just about there on the idle, 1/16th turn is all you want to move. Also you need your high speed set first, with the idle way rich to get a good adjustment. Screwing with the idle before getting the high speed set will just cause you frustration because you will not get it balanced out correctly.

All this assumes that your tank is set up correctly, right height in relation to the carb, and no leaks. The clunk is free to move, but will not bind in a corner. Same for the fuel lines, no leaks allowed. This allows air to get into the mix. Good fuel is also needed. If your fuel has sat open for a few months, it will not be at it's best. Borrow a tank of fuel from a buddy if you are unsure of the fuel. If it runs good on his fuel, and bad on yours, get a new jug. No difference, you can put the fuel out of mind.

Don