----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]----
Donald. Why don't you try a new set of spark plugs? Or at least try to find the offending plug by running the engine on the rough magneto for a minute, stop engine, find cold(er) cylinder and replace that spark plug. >From what I hear there is one plug just at the end of it's life and replacing it will probably solve your problem. Hartmut N3330H ----- Original Message ----- From: "Donald Perricone" <[EMAIL PROTECTED]> To: "Ercoupe Website" <[email protected]> Sent: Monday, December 12, 2005 8:20 PM Subject: [COUPERS-TECH] Ercoupe 415C Fouled plugs ----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]---- Anyone: We have a 415 C with a 75 Continental upgraded to a C-85 and with a Stromberg Carb. The engine has about 300 hours on it since major overhaul and about 150 hours since a top overhaul. It was brought back into service about 18 months ago after sitting idle for about three years. After a carb problem, which was fixed by replacing the needle valve, we have flown the plane about 60 hours in the last 18 months. In the last month or so we have had a rough mag check on the left mag and our A&P checked everything over and found nothing wrong with the ignition system. i.e. mags, wriing, plugs etc. As a last resort he switched the plugs from the top cylinders to the bottom and the problem went from the left mag to the right mag. He concluded that it was a plug problem and suggested that we pull all of the plugs and have them cleaned and gapped. This we did and the problem went away for awhile. After the plane sat idle for several days it started easily but the problem occured again but now ot was the right mag. Out of desperation and because we don't have a mixture control to lean out the engine to clear out the problem we ran it up to about 1,800 on only the bad mag and the problem went away. Now we had a good mag check. Problem solved - no! A few days later we tried to fly again and the same problem came back. This time we didn't have time to run it and try to burn out the fouled plug. Because we had some oil on the bad plugs we had our A&P do a compression check to see it there was any blow-by that was fouling the lower plugs. The compression check found every cylinder in the high 70s over 80 which was good news. Does anyone have any ideas about how ot solve this problem. We would like to hear from anyone who might have some suggestions. Thanks for your help. Don N93334 ============================================================================ == To leave this forum go to: http://ercoupers.com/lists.htm Search the archives on http://escribe.com/aviation/coupers-tech/ ============================================================================== To leave this forum go to: http://ercoupers.com/lists.htm Search the archives on http://escribe.com/aviation/coupers-tech/
