----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]----
John, try cleaning the air filter, but I think your problem is the idle mixture control. It sounds to me like the engine is running too lean at idle power. Have your AME richen it up a bit and see if that helps. Syd Cohen John Stevens wrote: > ----[Please read http://ercoupers.com/disclaimer.htm before following > any advice in this forum.]---- > > > I have been having an issue with my coupe at idle - she runs fine at > 900 rpm or better but seems to want to stall below this mark unless I > put the carb heat on. I have a C75-12F with a stromberg carb in mine > - the engine has just been "0" timed and have only put about 6 hours > on her thusfar. > > What I have found is that the RPM decreases with carb heat during > run-up (1500+ rpm) which is what I expect, the mags have 0 > differential between them during run-up but when I pull back the > throttle to idle the engine starts to sputter and stall unless I pull > the carb heat out. At this point she seems to idle well around 800 or > so rpm. The other solution is that I keep the RPM up around 900-1000 > without carb heat. > > This isn't a problem during cruise descent since I use carb heat and > leave the power setting up a bit anyway, I haven't tried pulling her > all the way back without carb heat in flight and am not in a hurry to > find out. > > Otherwise she starts pretty easily, and runs great at cruise power > (2000-2200 RPM). > > My AME (A&P) has messed a bit with the main mixture setting with > varying results (but no solution), he seems to think that it's a > sparkplug fouling issue (I'm running M100 mineral at the moment) but > I'm not convinced. Although the lower plugs may be fouling, the > uppers should still be clean and able to deal with the air/fuel > mixture for the short period that I have her in idle. > > Has anyone had this issue before or has any suggestions for > alleviating this issue? My feelings is that the effect of the carb > heat is having the effect of letting the engine breathe better and > that my air filter may be clogged up and in need of cleaning / > replacing. I am just throwing out the question in case somebody else > has seen the issue and has some experience with this problem. > > Any suggestions would be appreciated. > > John Stevens > 415-C owner going through withdrawl at the moment.... > > ========================================================================== ==== > 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/
<<attachment: winmail.dat>>
