Borzak

My Feedback: (2)

Ok I have a .46 OS LA that I run a lot (averaging about a gallon a week lately) that I've always tuned by ear. Problem is I have a hard time detecting pitch change for some reason. Because of this I know I run my engine on the rich side "just in case".

Well I got a tach and now I want to try and tune it by finding peaking RPM and backing off XXX RPM shy of that.

Question is - how many RPM shy of peak should I shoot for ?

I'm not looking for all out performance (most of my flying is at 1/2 throttle anyway) but rather a good mix of power/reliability/longevity of the engine.

Thanks.

adrian-RCU

300rpm down from peak is the norm

DarZeelon

Borzak,

Adrian is generally right.

My method is to cater for the position which make it hardest for the engine to suck fuel.
So I prefer pointing the nose straight-up, peaking it and then opening the needle to lower RPM by 100-150.

Do not do it like this with the plane level, or your mixture will be TOO LEAN. :stupid:

Flyboy Dave

My Feedback: (21)

....and the tach is only another indicator. There are too
many variables. One engine might continue to run slightly
rich....might run just fine....and another engine might
overheat.

Rarely will a problem with overheating....show up at half
throttle....most motors seem to run a little fat in the
middle anyway....

Dave.