Re: rough engine/power loss

[Claude Wheelbarger]

Hi Donald.  Had something happen with a Cessna a few years back. Carb hear fichens the mix so if it smooths out your going lean in flight. Try dropping the engine rpm's by 200 or so and ride that as long as you can. The problem I had was the float not allowing the needle valve to fully open and the engine would gradually get ahead of the fuel in the bowl. if I backed off of the marvel for a bit and let it get ahead of the engine (carb float bowl) it would smooth right out. Pull the drain plug, get a pan and open the fuel valve. There should be a nice drinking straw size stream. And if not remove the fuel line from the carb and do it again. if the fuel line is free it will really roll. If not you need to purge the lines providing any of this applies to you.   Sincerely  Claude Wheelbarger (W13)   ----- Original Message ----- From: Donald A.. Russell To: Coupers Sent: Friday, November 26, 1999 11:57 AM Subject: rough engine/power loss Hi all,   Would appreciate some thoughts regarding the problem(s) described below.   The engine is an 0200.   Everything is ok on runup,mag check,carb heat,mixture checks and takeoff are all good.   About 15 minutes into the flight( over the field!) the engine loses two to three hundred RPM and becomes slightly rough. Advancing the throttle to regain lost RPMs does not work unless throttle is first closed then reopened. This works for a few minutes and then problem reoccurs. Applying carb heat smooths the  engine but drops RPM even more. We're in sunny FL.   So far we've done the following: Marvel Carb with two pc venturi checked by Approved Repair Station, # 2 and # 4 cylinders reworked, also by Approved R/S. Mags overhauled ,reworked with new points, condensers and timed to engine. Also App. R/S .Compressions are all very high and uniform.