Bob Pastorello

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Please forgive if this is in some huge thread someplace; I need a quick response. Yesterday, on first Yak flights, engine adjusted perfect on ground, in air would richen in low range, but high end fine, not lean, sounded good - no sags.

I have the BME regulator vent hole adapter, and had a short line just terminating open in the cowl. Then removed it altogether, no better. Now have it plumbed with a piece of fuel line into the fuse compartment.

I've heard, and read, that this one thing solves the richening problem. Two questions;
1. Does it solve it?

2. If not, what OTHER things cause in flight richening, when ground setup is perfect?

Thanks in advance for any ideas.

mglavin

My Feedback: (31)

Bob

Venting the metering diaphragm to fuse often solves problem which are realized with air pressure changes realized within the cowl.

However a properly tuned engine is a paramount. Did you lean the low end until the engine sagged and then back it up slightly? Subsequent to performing the low-end tune-up you'll have to go back and tune the high speed needle.

BME has an excellent gas engine manual on their web-site which covers just about everything required to care and feed for your engine.

Bob Pastorello

My Feedback: (198)

Thanks, Michael. Downloaded the manual. It is MOST excellent, as these go. Just ran the motor, it was FAR better on the ground (so it was NOT so "perfect" before, obviously!), and I was able to tune the low end as you described.

Appreciate the confirmation!

(Got the servo, too - thanks!)