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Rotax 503 Won't Idle?????????????

Posted: Sat Oct 09, 2010 12:58 pm
by BuffDaddy
Greetings All:
Need your help!! I purchased a Quicksilver that sat for approximately 13 months. Owner passed away and had to wait for all legal stuff to clear sale. Here is the problem?: When started, will not idle worth a darn. Seems to run better at high rpm's but in idle position it will die out. I know it was running good when stored, now keeps dying out at idle. Changed plugs, fresh gas, still won't idle and dies. If you play with throttle it will start when you also use primer, then dies after a few seconds at idle position??

I took carb fuel bowls off, found some green stuff on bottom of bowels? Figured it was old gas.

Is it possible carbs need good cleaning with carb cleaner to clean out?? Might idle circuit be clogged? I really need your help on this one. Need to ferry plane to my home airport but not till running well.

Carbs are Bing 54 carbs, 36mm I believe? single cable entry on top of carbs. Engine is a 503, duel carb, CDI ignition.

THANKS in advance for your ideas and help in this matter.

BuffDaddy

Sucks and Blows

Posted: Mon Oct 11, 2010 1:48 pm
by bryancobb
A 2-Stroke sucks and blows. Sucks everywhere before combustion, and blows everywhere after combustion.

I'll bet you have an air leak on the "suck" side.

While it's running, spray starting fluid or WD-40 around all the possible leak points on the "suck" side. ( I.E. joint where crankcase halves meet)
If the rpm increase, you have a leak.

Posted: Tue Oct 12, 2010 2:20 pm
by Jeff Tipton