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The owners manual may trump the type certificate. Maybe not. At any rate, you cited 2150 and that's definitely low. As John said, static rpm is measured STATIONARY with zero wind. (If there's a breeze, turn the prop sideways to the wind so it won't be a factor.) Check the tach first since those are so often wrong. Then, I'd check the engine because you shouldn't be ABLE to be below the prescribed range with a normally operating engine. John was quite right that your rpms should be a couple hundred higher than static by the time you reach rotation speed. Once you know the engine is working properly, if your rpms and performance are still low then you can consider getting the prop repitched to 7148. (Borrow one first and see how you like it.) I don't remember it being very expensive but my repitching was done about 20 years ago and there's been some inflation since then. I remember $300 in 1983 dollars and I do NOT trust that memory. If it were me (and it was), I'd prefer to have my rpms nearer the TOP end of the allowed range. The downside is that it slows your cruise speed at a given rpm. I flew coast to coast at 100 mph quite happily and really liked the climb performance on a LOT of occasions. (Also, good climb can increase your cruise effective speed by letting you go high and lean for much increased flight-leg range and fewer fuel stops.) Your mileage may vary. Ed Burkhead http://edburkhead.com/ [EMAIL PROTECTED] -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Monday, April 14, 2003 9:58 PM To: [EMAIL PROTECTED] Subject: Re: Alon A2 with poor take-off performance Ed I went back to check my figures and my origional Alon A2 owners manual, Dated December 1965, lists the following prop application info : McCauley Model 1B90CM 7148 static RPM 2225 to 2325 McCauley Model 1B90CM 7150 static RPM 2175 to 2275 McCauley Model 1A150/scm 7153 static RPM 2175 to 2275 Max continuous engine RPM 2475 Bob Bullock N5621 Maryland ========================================================================== ==== To leave this forum go to: http://ercoupers.com/lists.htm Search the archives on http://escribe.com/aviation/coupers/
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