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My Feedback: (8)

I have a new DLE 30 that is mounted to a Sig 1/4 Scale Cub. For scale purposes, the cowling has only a minimal amount of cut outs for cooling the cylinder head. I have run about 1/2 - 3/4 gallon of fuel through the engine to date and notice that the engine sounds like it is loading up in flight. Obviously I could lean the low end but I am wondering if the air/fuel ratio is getting too rich because of the tight cowling limiting the amount of air getting to the carb. Any thoughts on this? Thanks

ahicks

My Feedback: (2)

As long as the carb has room to breathe between it and the firewall, I would think that if there's enough air circulating through that cowl to keep the engine cool, the carb would not have any difficulty getting enough air to run properly. That's my take though....

av8tor1977

My Feedback: (6)

I am not sure if this is your situation. A lot of people think an engine does not need to be tuned, and that the "FACTORY SETTINGS" should work. This is far from true. The factory settings are good only for getting the engine started, (maybe/hopefully), and then you need to tune it from there. Every single engine, and it's prop, fuel, installation, altitude, temperature, etc., etc. etc. is unique and MUST be individually tuned. There is no such thing as a factory setting that will be, in many cases, anywhere near what the engine will actually need for a setting for a given person's application and particular engine.

Now, having said that, there is another problem that can occur. If the engine runs perfectly and is well tuned on the ground, but then goes rich in flight, it could be that the carburetor regulator is sensing a too high pressure due to ram air pressure in a cowled installation. In this case, installing a fitting in the thin metal cover over the regulator in the carb, and running a hose from there to inside the fuselage where there is no ram air pressure should cure the problem.

AV8TOR

ahicks

My Feedback: (2)

OK, another thought. How does it run without the cowl (on the ground/in the air)?

dant-RCU

My Feedback: (3)

Do what ahicks suggests first. If you still have problems you might want to look up "Hippy Jim" as he is one of our local Cub experts.

Dan