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Old 11-07-2005, 02:20 PM
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tande
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Default RE: "Calling All "WALBRO" Experts"

Thanks Guys for the response!---For those who care, I just talked with Luis Salas at "Walbro" (Thanks to RCIGN1 for that tip!) & he confirmed that the check/valve is indeed designed to prevent air back/bleed into the fuel reservoir where it CAN mess with idle circuit fuel calibration---Said his personal opinion is that ALL carb models should have it & knows of many in the racing world who modify their carbs to use it (Sounds like the spray/bar-check/valve is available as a service part---forgot to ask---oh well!)---Now why does all this concern me?---Well, I have two YW48 twins (Nice engines aside from this particular complaint) that I cannot get to idle down in the air, to set/up for a landing (Idle sounds like maybe 3000 RPM, who knows)---After they are on the runway & come to a stop the RPM's will drop right down---Seems as though it has something to do with the engine being "Windmilled" by the prop while moving through the air & I am wondering about the low speed mixture "Leaning out" with the throttle pulled back---I can somewhat help the condition by adjusting the low speed mixture to the rich side but then the midrange & transition falls all apart!---Thought about the spark advance curve not cooperating---Talked with "Terry" at "C.H. Electronics" & agreed it might be a possibility---Tried one of their (C.H.) spark advance circuit boards---No dice!---Any thoughts Guys!--
Thanks to all---