Rockohaulic
Elite Veteran
Location: Valencia, CA, USA, 3rd Rock from the Sun
| Aaaarghhh! I'm chasing an engine twitch in my Hurrican, and after spending (wasting) 4 hours last night, nothing made a difference!
It's a Hyper 50 with a CY MPII pipe. In a hover, the engine twitches or hesitates or whatever you want to call it. Of course when it twitches, the heli, or tail, also twitches back and forth.
So I got some good input from here, and last night I tore her apart and went to work. Here is what I did:
Checked header tank and drilled out inlet as it looked very small or even blocked. Sorry I don't have the size of the drill bit, but it's the smallest one that comes in a normal kit.
Removed head and re-installed (to check if head bolts were tight).
Replaced fuel lines.
Checked clunk lines - looked good (Hayes black).
Removed carb, disassembled, cleaned with carb cleaner, reassembled and reinstalled.
Replaced glow plug.
Today it acted exactly like it did last time I flew it!!! Aaaargh!!
Here's the really strange thing. I tried all kinds of needle settings, and it just didn't seem to make a big difference. I leaned it all the way to 1 1/4 turns, and only at 1 1/4 did it finally make a difference. I richened it to 2 full turns, and it still twitched. I even tried 2 1/2 turns, and it still twitched.
At the richer settings it only ran slightly cooler (109 backplate and around 195 head), and at the leaner settings it only ran slightly warmer (115 to 119 @ backplate, and around 200 at head). I was very surprised that these big needle setting differences did not see changes in the twitching or larger changes in temperature! 
Any ideas where I need to spend my next 4 hours??? 
I got a helicopter for my girlfriend,
It was a good trade! |
