wootdog

My Feedback: (65)

I am running a D&B 3.7 (60cc) 2 cycle twin and have encountered some unusual trouble tunning the motor. In the past I have had great perfomance from the engine but as of late I can't seem to get the same performance in the air as I get setting up the engine on the ground. The engine has been tuned to peak high and low rpm on the ground holding the aircraft stationary, but once it leaves the runway the engine never really makes it's peak rpm. I have installed new plugs, cleaned the carb, and even tried a new synthetic racing oil (recommended by experienced tournament pilot friend) and I still get the same results. As far as I can tell the fuel tank and lines are ok. I live in the Charlotte area of North Carolina and it was suggested to me that my trouble could be the exceptional amount of moisture and humidity in the air right now but who knows. Does anyone ahev any suggestions that might help. Thanks.......Wootdog

Aero330LX

My Feedback: (-1)

Hi Wootdog,
I live just down the road not to far from you. :-) When you cleaned the carb did you clean the the screen? I'm asuming this engine has a walbro on it. Most of the D&B's I've seen have had walbros, so I'm assuming that's what comes on them. Has this engine always done this on the plane it is on now or is this something that just started up with this particular plane? Does it burble like it trying to come up to rpm or does it sound kinda harsh like it's 'laying down'? If you would like, I'll be going out again tomorrow about mid-day to do some flying at Mocksville (WSRC) and we could put our heads together on it. Are you coming to the WSRC Spring IMAC this weekend? I'll be there and it looks like it's gonna be a good turnout. Lemme know if you would like to get together and we could see what's up and do some flying.

wootdog

My Feedback: (65)

Greetings Aero 330LX,
Thanks for the response. I did clean the screen and the trouble has been basically on my present plane (GSPlanes Staudacher).
Last summer the engine ran great, this year a different story. It really does not burble much at all but sound more like I am flying at 2/3rds throttle but it is wide open. When I hold the plane on the ground the pulling power is impressive but in the air it just ain't gettin' there. I have a friend that practices his aerobatics near Mocksville and I am wondering if it is the same field you frequent. Email me at > [email protected] < . See ya

Antique

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Check the diaphragm under the cover held on by 4 screws...If it's at all stiff or sounds "crinkely" replace it....A carb diaphragm kit is only about $6.00 at a small engine or chainsaw shop.....

DKjens

My Feedback: (50)

Did it run fine last year in the same plane/cowl/cut-outs etc.? If something in that has changed, it could be that a high or low pressure is forming around the carb. when plane is flying, and that screws up the mixture.
DKjens