ameyam

Flying a Phoenix Extra 330s 60-90 with a Dle20. I had two days of flying this weekend. Initially, I had a lot of trouble with controlling the sink rate at landing. When I added power to control altitude, it would react late and just bounce, power would come in after it had already hit. Luckily, the aluminium LG absorbed the shock

Today, I was just getting to terms with the throttle and getting used to the high throws when the engine cut in successive flights when doing a loop. I had seen it lose power and struggle in the upward section just before the deadstick and was thinking that this was due to insufficient airspeed or mistake on my part so I persisted with the loops. On the second deadstick, it was just my first loop. It flew fine till then, (rolling and figure-of-8 flying only) and even went to 60% power at takeoff at a 30 or so degree angle that we typically use . Both times after the deadstick I had to land heavy and downwind so after the second flight, the LG was nearly flat. Needless to say, that was that for the day.

After coming back home, I opened everything. Fuel tank is OK, no stuck clunk. There is a lot of blackning on the engine from some leakages (I am using Klotz, I think 1:30). I discovered a cut in the carb line but I am not sure that it was caused before or during this overhaul. Anyway, I cut off the nicked section and reinstalled the engine

Another thing I checked was the carb filter. There wasnt anything in the filter fabric but there was a lot of crud in the recessed circular part towards the head. I dont think there is any way to back flush this so I just cleaned it with come cotton buds, reinstalled the filter fabric and reinstalled the carb.

I am also attaching a video of the piston side, just to confirm everything is ok. (I should have used a better camera)

http://youtu.be/1Sdx2rSYDu4

Subsequently I started the engine and after a bit of trimming I had her idling at 1700rpm. I hadnt touched the needles after factory and I cant run WOT indoors so I slowly closed the LSN at idle. Surprisingly it went all the up to 4000rpm (onboard tach) before I got spooked and returned it to the originally setting. So my questions:

1) Any idea what caused the throttle to cut in the upward part of the loop?

2) Are there any other variables (besides the needles which I can only set of Saturday now) that I can eliminate from the setup? Did I need to clean anything else/ any other way / do anything else to the carb?

3) How do I set the LSN?

Remember, I still have problems with the engine reacting late to the throttle at this needle setting. Without expo, the throttle would over-react to small power increase so we had to add 100% expo and now I have the opposite problem. I did drop my expos to 90% and that did help a bit today

Ameyam

ahicks

My Feedback: (2)

It's time to change the factory needle settings. Trying to teach yourself how to tune an engine is likely going to turn pretty frustrating. Might be different if you were flying a trainer. If there is help available, I'd advise seeking that out. The "reacting late" and probably loss of power while vertical are both signs of a carb in need of adjustment.

Cyberwolf

My Feedback: (4)

http://prme.nl/forum/viewtopic.php?t=10, http://indianatinygasengines.com/page3.aspx, aircraftproving grounds.com These are just a few of the numerous places a person can go to get help with tuning a gas engine.

a1pcfixer

My Feedback: (7)

I'm certain I posted the following to you in the past.......

Jody's gas engine tuning tips (pdf files);
http://www.rcuniverse.com/forum/fb.asp?m=10293852

ameyam

I did go over the answers I had gotten earlier but missed this one. I will check and then revert

Ameyam