by lazflyn » Wed Aug 31, 2005 7:06 pm
Hey guys,
Thanks for your help and suggestions. George had an idea for me to swap the position of the engines (move the good engine over to the "bad side"). That way I could check to see if everything that hooks up to the troubled engine is good or not. Like for instance the fuel line, the muffler, and the ground/kill wire. I did that last night with no new leads. The good engine ran just like it was on the "good" side. So my fuel system, fuel, muffler, kill switch/wire are not causing any problems. By the way, I do know exactly how my engine runs when it starts sucking air bubbles. I flew my plane over 200 hours last year. When I got much over 7000 msl, air bubbles started to grow. Course when that happened, my engine would sag. Interestingly though, the same engine that would create the most air bubbles is the very one that is now the problem child. I don't see any bubbles in the line while I try to get it to run on the ground. Solid fuel all the way to the carb. By the way, the fuel line is about 14 months old. The fuel strainer has been checked and I do not have a check valve. It is a straight run of fuel line from the bottom of the tank all the way to the carb. I flushed the tank at the start of this year since I wanted everything to be perfect for a new flying season. Just to kill any idea that maybe there is some junk in the bottom of the tank or something like that, let me repeat myself:
This engine problem started around September of LAST YEAR. I have put many, many tanks of fuel through these engines since this problem came up at that time. Most of the time the engine would smooth out, so I could easily fly the airplane. So right or wrong, I did. I've probably put about 80 hours or so on the engine since it started giving me problems. The problem has gotten worse to the point that now it hardly ever smooths out while trying to go to full throttle. Some days are better than others, but it happens now every time I fly and really won't smooth out unless I'm lucky after 10 minutes of playing with the needles. I stole the carb off the good running engine and put it on the bad engine with no change in its behavior.
I'm at a total loss as to what it could be.
MarkDJ.