jschenck
Elite Veteran
Location: La Vista, NE.
| you and I are about in the same place as far as tuning our gasser's but sounds like you've made real headway!
I'm just about to finish my first gallon, did another 2-3 tanks tonight. My Predator is flying pretty good. I did bump up the headspeed by increasing the throttle curves. I still have the needles at about 1.5 out on both sides. My pitch curve is almost dead on to what Raja describes, 11,6,0,-6,-11 with the radio at 0-inh-inh-50-inh-inh-100 in all flight modes.
But, here is where things are getting a bit confusing for me - this being my inexperience with gassers. My heli is definitly running a lot hotter than it was. I can hear it and smell it. Today was warmer than previous flying days but not a whole lot.
My Throttle curve: (X9303 has 7 point curves)
Normal: 8-17-20-27-30-45-100
Idle-1: 100,45,30,27,30,45,100
Idle-2: 100-50-38-30-38-50-100
This heli was definitely not running a high headspeed ~1600rpm in idle-2. Everything tells me I'm running rich except the engine! I was shooting 200-240 degrees at the exhaust port and the fins just under the fan shroud exit. I am not getting the black oil splatter that I was getting the first few tanks. I do see smoke in the exhaust but it's dissipating after a few minutes of flying then I don't see it. I don't feel that the engine is sagging and top end/full throttle power does not seem to be there like it's rich on the H needle. And I had the L needle rich enough to where it would not idle until I bumped the throttle up even with the trim all the way up. It idled fine when the L needle was at 1 3/8. Also I was getting surging at idle after a flight, even would die if I didn't add a touch of throttle.
This photo is a bit deceptive I think - my eye's tell me the plug looked a bit lighter in color than this. I'm going to open a separate thread on my other issue I found after flying - the main gear. It may be related to the engine tuning?
Z-RC intake in place, 4OZ of lawnboy in 87 octane fuel Hanson-26 with 643 carb.
EDIT: Forgot to add: running the stock airbox aircleaner.
...yep... |
Mine gurgel ' d also when they where breaking in, they may be a touch hot, do to a way thick mixture.
