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cuynua 430 thro problems with air filter

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corvettercr

Well-Known Member
Joined
Jun 15, 2011
Messages
55
Location
erick oklahoma
hi guys, have a question about my cuyuna 430, i bought this on a b1-rd awhile back and she runs/flies great. engine has a fresh overhaul however i nor the orig owner can get her to thro up with various airfilters installed. for one..............

all stock 430 with a mic 28mm carb.
panzoil 40:1 dino oil and 87 octane gas. non corn gas

what it does................

start it up with foam filter installed, idles great and will start to rev up but once you hit a few thousand rpm she simplies falls on her ass. wont die but the rpm just starts to drop. i remove the filter and she revs right on up. w/o the filter im getting 5000rpm max and i cruse right @ 4300 rpm. yes i have been flying w/o the filter and i know its a no no but..........

when i bought the plane it had a k&n cone style filter on it and the guy told me about what it was doing. so i bought an all foam filter per cuyuna's recomendations and well it still does it.

now i did talk to some ppl that know this engine brand and they also said it needs a 32mm carb and that might be my problem. also could be jeted wrong. well if it is jetted wrong im not sure which way to go here, lean or rich.

i can say if she sits over night i have to pull the plugs and either them out due to being mounted inverted and filling with fuel. once dried she will fire right up and run great with no air filter.

so it is a jetting prob, carb too small 28 vs. 32mm or what????? this is driving me nuts here and i would like the engine to last me a long time, and please no preaching to me about not using the breather. i know its not good on them at all, i have been a mechanic for over 20 years and a moddeler for 27 years. i know what im doing is not good on the engine. please help me get this figured out guys. thanks steve
 

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