bh motor tuning

[reefguy]

i have a xcell gasser with bh hanson g23 with 644 carb, with a tuned pipe, using camp fuel with 64 to 1, it runs good right now, but was wondering if it can be tuned for better performance, currently the needles are set at high = 1 1/4 and low = 1 1/8, are these settings okay or was wondering could it be bit richer or leaner on one or both sides. thanks for any advice from the gurus would be greatly appreaciated. tony..

[Tom Fiddler]

Engine tuning is more of a sound /feel thing, and needle settings are affected greatly by exhaust, compression ratio and other mods.
I wish I could tell you to "open the high needle an eighth" but it just doesn't work that way.
You must experiment with your heli in your weather conditions to tune for maximum power
Make small changes and try to learn what these changes do.
You cant hurt an engine by going to rich
It's hard to explain but when you get too lean the engine note will sound kinda "hollow"

Wish I could help you more, but if it was real easy to tune an engine nobody's engine would ever run bad :shock:

[reefguy]

i understand the real way to tune a motor is by listening to the motor, i guess i was just wondering if my current needle settings seemed okay or not. tony..

[bigrcr]

Tony,

As Tom says, always err to the rich side on your needle settings. Your setting sound OK for this motor, depending on the carb used.

To initially set up the low needle, make it purposely rich (the tail will kick as you apply power). Then take the low end in a bit at a time listening for the motor to clean up and the tail to stop kicking. The low needle commands the mixtures through hover-range where the high needle picks up nearer wide open throttle. Listen and watch the machine. A burble accompanied by a tail twitch is still rich. As you adjust leaner and this goes away, stop. A lean bottom end condition will show up first in the skids as a vibration. Once set, you can then work on the high end needle.

High needle: Once again, start from rich and do powered climbs and listen for a rich condition at wide open throttle. A sag or bog could be taken as either rich or lean (this is why you make it purposely rich). Richen up the top and see if it gets better, if worse go leaner and then try again. What you are looking for is a good hard "pull" without a sag and as always err to the rich side (take in mind the gas needles have a much narrower operating window). Do not mistake the motor "loading" for a bog (this is where the ear comes in). The high needle is hardest to get right so take this in small steps and develop an ear for it.

Hope this helps!!

[reefguy]

thanks, will do that on my next flight day, tony..

[Al Magaloff]

I also agree with the above "masters". My saying is " When in doubt, turn the screws OUT".