trouble with a jiffy auger. Need high rpm throttle help

[ZEEK1223]

I am by no means a small engine repair man, but I would call myself pretty handy. My buddy brought me an older jiffy auger that would not run. I pulled the carb and cleaned it, new plug, and new gas. The auger will now start, and idle very well. My problem is with the high throttle. I noticedd there are 2 screws for adjustment. I am used to just one. The auger will drill a hole just fine, but it is not running at peak power. While drilling a hole, the auger will hit that sweet spot that I know it should be running at, but will just bog down again and give me a sub par drilling experience. I could have cleaned the carb a little better. When I adjust either of the two screws they are very responsive making the engine run hot, or bog down.......any advice would be great!!!!!!!!!!!!

[fishNcrappie]

i am by no means a mechanic and you probably know this already. the 2 screws would be high idle screw adjustment and low idle adjustment.if bogging down when throttling my guess would be to hold wide open and adjust the high idle until running smooth. i'm sure someone with more knowledge will jump in. would try and do this outside. (rather then in side warm garage)

[harleyharry]

I am assuming that this is one of the old three hp engines.

The carb adjustments should be as follows. When looking at the side of the carb with the adjustment screws, the one on the right is the high speed mixture screw, the one on the left is the low speed idle mixture screw.

Turn the screws in until they stop. Then back them out one turn counterclockwise. Run the engine and warm it up. I usually do this with the auger removed. Here is the tricky part. The engine will never sound good at high speed, on a sustained speed. The rpms will always sound like the engine is missing. I rev the engine up for about two seconds and listen to the engine as it is reving up. If the adjustments are correct, you will hear the sweet spot you refer to in the rpms. If you cannot, turn the low speed idle mixture screw in an eighth of a turn. If everything is good, you should have a good running auger.

Just to complicate your day, your old auger may be old enough to have points. Tecumseh used points in the old three horse engines until about 1988. If the points are dirty or carboned up, you will not get enough flame at the spark plug to get a good burn on the fuel.

Harry