There are two adjustments. One for high speed marked 'H' ...the other for low speed marked 'L' .
I've always set mine by warming the engine first then while its running on idle, turn the low speed screw in till the engine slows somewhat, then back it out the other way till it slows down again that way. Somewhere in between is the best setting. If the idle rpm keeps raising as you find the best setting, just keep backing off the idle control screw on the other end of the carb then repeat the above process if necessary.
As for the high speed screw, I adjust it in, or out until it doesn't bog or go flat when you quick rev it, then keep turning whichever way until it runs fast without a spongy flat sensation in the throttle.
May want to inspect the little fuel lines from the pump bulb. They can get hard over time and then split on the ends.
Charles, May 2008
