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sparkplugs
#31
One thing I haven't seen here is that if all the temps are in their proper ranges, moving up a step or two in spark plug heat range may solve the carbon problem on the plugs.

A plug that's a step or two colder than needed will carbon foul, regardless of the mixture being set perfectly.

I suggest that if all other criteria are in order, a slightly hotter plug may be the correct solution to carbon fouled plugs.
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#32
marcher07 - 10/20/2011 10:19 PM
...There manual show a slightly diffrent range of operation though not significant:
Main jet operation between 60 and 100%,
Needle jet/jet needle between 80 and 15 %
Idle between 25% and 0%...

These numbers, I am sure, are the accurate ones. My 0% 25% 75% and 100% were approximations without searching for reference materials. You reminded me that there is some overlap.

...Not sure I understand “The amount of time you spend hovering vs. cruising around, combined with your takeoff weight, may have something to do with your black or tan plugs”....

What I was saying was, a light ship/pilot may very well be able to hover with a small amount of collective (carb opening) that is in the zone where the Bings are on the midrange jets, where a heavier pilot will hover on the main jets.

If you assume that the main jets are correct for 1175 EGT, and the midrange is jetted perfectly for a helicopter (a little rich)
then a heavy pilot spending 100% of his flying doing hovering will have pretty tan plugs. If he spends 2% hovering and 98% flying around at 65% power, his plugs will look black.
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#33
Yep, I think this is right. I seldom spend much time hovering anymore, and plugs are always black. Having said that, I have never had one of the fine wire plugs load up and cause any hesitation in throttle response.
Skeeter
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#34
Yesterday I discovered my Bing needle clips were in the middle slot, so just for fun I moved them to the bottom (max rich) and went flying. Wow, nice low temps but the engine ran rough, coughing and missing in forward flight, so for more fun I moved the clips to the top (max lean) and bingo, it ran smooth and nice. Nothing subtle about this - it made a big difference. Temps: 1080, 340 hovering. Have not checked brand new Iridium plugs yet.
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#35
BINGO LARRY! You're spot on! I wish I could get mine dialed in that close, but still might. Say I liked your last video.
Rob2
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#36
Larry,

Are you a big guy or little guy? Is your ship heavy or a sparsly equipped light ship.

Mr. Uptigrove can chime in and comment if I'm wrong but 1080 seems pretty rich!
My guess is, if you get the temps up to 1150-1175, your engine will get into the power band and and really come alive.

DO NOT follow my suggestion here until John or Dwight OK my comments.

If you have a new set of the Non-Iridium plugs, put them in with your current jetting and go fly for a couple of hours.
Then pull the plugs and inspect them. If they are not tan, you are too rich.
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#37
bryancobb - 10/22/2011 2:33 PM
Are you a big guy or little guy? Is your ship heavy or a sparsly equipped light ship.
I'm the "ideal" average pilot at 175 pounds.

bryancobb - 10/22/2011 2:33 PM
1080 seems pretty rich! ... if you get the temps up to 1150-1175, your engine will get into the power band and and really come alive.
Brian, wow, I remember landing just so I could write down the temps on my seat (because my memory is so shot) - I went over to check and wow you are right on! I wrote "Rich" 1080/295, and "lean" 1120/340. "lean" ran so much better - just amazing to me that temps are such a good indicator... geessshhhh, 1120 is only 40 degrees more, less than 4 percent! --- OK, I'm a believer, temps tell.

bryancobb - 10/22/2011 2:33 PM
If you have a new set of the Non-Iridium plugs, put them in with your current jetting and go fly for a couple of hours.
Then pull the plugs and inspect them. If they are not tan, you are too rich.
Will do. --- I should also check my needle jet #'s so apples and oranges stay in their baskets. Skeeter has 165 mains and I probably have 195's (whatever "mains" are, I'll figure it out and apply for a PhD) -thanks,
-larry,
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#38
Just found and read this. This was AFTER we sold the Mini-500. I realize the Mini and Mos are apples and oranges, but the principles still apply, especially how they advocate putting weight on plywood in the skids and checking jetting throughout the power range, ON THE GROUND.
http://www.millenniumhelicopters.com/...
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