Mid-range need adjustment

[Jotto]

I have purchased a new Align 91HP engine and will start breaking it in and tuning it this weekend.

I want to make sure that I do it correctly this time ( http://helifreak.com/showthread.php?t=198145 .. errrr...), so I have read quite a bit about tuning and watched Bert Kammerer's video at http://www.smacktalkrc.com/.

There is still one thing that is unclear to me. Suppose I to the following

1) Break in 2-3 tanks with factory settings (2 turns out on high and mid needles)
2) Lean the high end to a conservative (on the rich side) setting where the engine runs fine

Now I'm supposed to tune the mid range. Bert's video explains what a lean condition in the mid range sounds and looks like, but nothing about what a rich condition looks like. How do I know if I should lean the mid range? I assume that two turns out on the mid range needle is usually too rich (Bert is actually starting at 1.75 on both needles before tuning).

I don't need to tune the engine for maximum performance, but I want the engine to run nicely and not waste fuel.

[w3ub]

Here is an old post about tuning that helped me.

http://www.helifreak.com/showpost.php?p=1506350&postcount=36

[Jotto]

Thanks! I'll have a look on it!

[w3ub]

Just to add a couple of things ... and I am not an expert by any means ...

Don't expect to see really obvious signs of going to lean. By the time things are really obvious it is probably really lean. Look for subtle signs.

Things I notice and look for are how the engine speed falls off when not using the governor (which you should not be using till she is broken in).

If you do a simple vertical climb out then reduce pitch and power does the engine overspeed or hang for a while? If so, it may be lean. Like the article says, the same thing applies when unloaded at the top of a loop.

If you come touch down after a hover and reduce throttle, if the mid and low are really lean you may notice the engine speed hangs up there longer than it should.

Just keep looking for those subtle signs! On my two HZs, running Magnum 30DS (also was the same at CP30), I run the mid at 1.5 turns, and the high two or three clicks in from 1.5 turns. This may not be the case for you, just tune it for your conditions.