If choking off one carb causes an rpm increase it may be that you have an
air leak somewhere... crankshaft seals perhaps, or a case seal? Have you
done a pressure test on the engine?
The previous owner of my plane (Cuyuna, not Rotax, but they're similar)
went crazy trying to get the engine to run right until he discovered the
center crankshaft seal was bad (or more accurately, a good seal installed
incorrectly).
-Dana
At 07:17 PM 11/18/2009, rayw wrote:
>I could use some help. I am running out of idea's. I have a 503 with dual
>Bing 54 carb's. The engine starts and runs well up to about 2000 RPM.
>After this RPM it has nothing left it just bogs. I have gone through both
>carbs so many times I could do it in my sleep. I don't think it is fuel
>pump problem because I have rebuilt it and I have used the primer bulb to
>try to compensate for a potentially bad pump but this has no effect. The
>other day I ran it up to a point just before it bogged and put three
>fingers in front of the inlet of the right carb and got it to bog. I put
>three fingers in front of the inlet on the left carb and got a 1000 RPM
>rise. The carb on the left is an older type so I bought a brand new carb.
>Would you believe it? Same exact reaction. I went through the timing but I
>will probably go through it again to double check. Any body got any
>idea's? I have done so much that I can't even remember it all.
>
>Ray W.
>
>
>Read this topic online here:
>
>http://forums.matronics.com/viewtopic.php?p=273634#273634
>
>
--
Society is like a stew. If you don't keep it stirred up, you get a lot of
scum on top.
