Don wrote- >I gather they can be made to work >will give the posa another shot >am interested in feedback both pro and con
Well, since it's Friday I guess it's OK to whip a dead horse a little. My only experience with the POSA is not first-hand really; it's with my friend Paul Martin's KR-2. He had a very stock KR-2 with a very stock 1835 VW and ran a POSA on it. Successfully, for (I believe) about 150 hrs. before he sold it. He was all set to fly it from southern Oregon to Oshkosh one year, but situations changed and he didn't do it, but he had that kind of confidence in the airplane and engine. Paul, like others who were able to make the POSA run, went through the "swinging a dead chicken while jumping on one foot" routine. It involves shaping the middle section of the needle to just the right contour to avoid a flat spot in the engine midrange. Usually it can be made to run OK at wide open throttle and at idle, but either stumbles, stalls, or runs rich at midrange. The secret involves tying down the airplane and running the engine at several different increments of throttle, killing the engine at a fixed RPM with everything stable, and reading the plugs and gauges (EGT, etc.) to see if it's rich or lean at that RPM, then either building up the needle (if it's too rich) or filing it down (if it's too lean). This is done at several settings and then the needle is sort of polished or smoothed out to take any 'steps' out of it. Then you run another round to make sure you got it right, or just go fly it and see if it works OK. I believe I've seen or heard something about filing a flat onto the needle too, but that just may be part of the lore that goes with this unit. I think the goosey part is when you're on short final at reduced power and see that you're going to be short and blip the throttle. You don't want it to stumble or quit right then ;o) If all else fails, I understand you can do one of two things (after opening a cold beer): (1) start swinging a dead chicken over your head while hopping on one foot, or (2) aim the unit for the nearest trash can. Some have done both; others have settled for the cold beer and forgot what they were doing to begin with. Happy Friday! Oscar Zuniga San Antonio, TX mailto: [email protected] website at http://www.flysquirrel.net
