Re: [COUPERS-TECH] Running rough

[MAGIC VAC]

I seem to remember that the purpose of leaning is to gain maximum rpm, not to lose it.  If you are leaning to the point that rpm drops, you've gone past the point of optimum burn, and you're running way lean.  Take it a little slower, and see if you gain some rpm before it starts to drop off,  then richen it up to max rpm.   Larry ----- Original Message ----- From: John Bennett To: tech@ercoupers.com Sent: Saturday, July 19, 2003 3:53 PM Subject: [COUPERS-TECH] Running rough Hello Coupers, I've had 2454H for about four months.  I went flying this morning.  The purpose was to calculate fuel burn. After topping off the tanks, I took off and climbed to 5500' and returned to the airport.  I was at full throttle until descent to land. Total time from engine start to stop was 00:43.     After topping off again with 3.15 gal of fuel, I took off and climbed to 4000'.  When I reached altitude, I was at full power, indicating 122 MPH on the GPS.  My plan was to fly out for 00:30 and return.  I tried to lean the mixture but with the mixture pulled all the way out I only saw about one or two hundred rpm drop so I returned it to full rich.  I wanted to descend to 3000' going back so I pulled the throttle back to 2100 rpm. It started running rough.  I went back to full throttle and it smoothed out after a few min.  By this time I'm heading back home.  After flying about ten min. I pulled the throttle back again and again it started running rough and losing rpm.  I went back to full throttle again and it smoothed out for the most part.  I will say that even at full power, it still seems to run a little less smooth than it did.  At one point the rpm’s went down to about 1500.  It was starting to get scary but it smoothed out again and I kept my speed and altitude until I was within gliding distance of the airport.    By the time I reached the airport it seemed to be running normally.  I am flying a D model with, I believe, all the E up grades. C-85 engine, rudder peddles and split elevator. Can anyone offer an idea of what to look for?  Thanks, John Bennett N2454H ____________________________________________________   IncrediMail - Email has finally evolved - Click Here