flyitrite

After looking at many of the posts to find some help for my issue, I decided to just join up and see if I could get some help that way. I have a new YS 115 and recently ran it in per the manual and installed it in the plane. After starting and warm-up I got it to fly ok for a short flight and landed after about a minute or two and checked out everything. Restarted and flew a bit longer about 1/4 to 1/2 throttle and the engine died in flight so I landed and checked everything / all looked ok. All subsequent flights ( 6 ) have been deadstick. It usually seems to run up and down once or twice during flight and then die, sometimes after a throttle change. Seems to be ok level only and part throttle only but any high speed + throttle changes will kill it. It was 400 rich of peak last time I ran it. Engine shipped with a bad jam nut and I had to use a light hub, no reply from YS email and several phone attempts are busy. Fuel is VP 20/20, plug is OS- F , 460 elevation, 73 degree f, APC 16x8 pattern. Tac peaks 9xxx- 91xxx k. Engine is a beast other than deadsticks. Thanks for the help.

Wild Beat

How does the tank look? The clunk isn't getting caught anywhere in the tank that would mean that the engine is starved of fuel after the tank drains to a certain level?

flyitrite

Thanks Wild for the reply, tonight was interesting at the field. Called and talked to YS and the person was very nice and helpful. Rechecked hs needle per their recommendations and took the plane up again. Awesome performance just half throttle flying and several people at the field watching. Then about the same time in flight as before ( new tank, lines, fittings, clunk) it died. This time I noticed how the plane lost elevator control just before the throttle cut. Earlier when this happened I thought it was due to the lack of airflow from the engine but now I know the RX was going to failsafe!! I have the Tactic 650 with the 624 rx. Don't know what to do about this yet but I did email Hobbico. Running four Hitec 485 hb servos and one micro JR for the throttle. I guess I need to ask in another forum for radio stuff?

flyitrite

New question. When I start the engine and let it run a bit then go to full throttle it has a crazy rpm peak ( about 9100 9200 ) ! After turning the needle out and then leaning it , I will usually get 8750 tops and 5 - 7 clicks don't seem to do much one way or the other. As far as the low needle goes can anyone tell me how many turns out is typical. I started at the recommended 2 turns and leaned it to around 3. Still OS-F plug ,VP 20/20 fuel, APC 16x8, Not cowled.

Wild Beat

3 turns sounds a little rich, I had one which ran at 1 3/4 if I remember correctly. For me it was a fly and forget sort of engine I never needed to touch the needle.
To set the needle up I would start it a little rich (around 2 turns), let it warm up, then lean in the needle until the smoke started to thin out. I'd then open it maybe an 1/8 of a turn from that. Then I'd check the throttling and idle, and if that was good I'd just fly it.In flight make sure there's a good smoke trail, from there it should be good to go. I never touched the regulator on that engine.

Remember when adjusting the needles to give it a few seconds to wait for a change, it takes a little time for the change to take effect.

flyitrite

Thanks wild for the help. The 3 turns out was on the low needle, I am trying to see where it usually is for most people. turning it out leans it as I understand. On the HS needle it seems to be around 1 1/4 to 1 1/2 turns. Never noticed an engine like this that will peak and does not do much for 5-7 clicks more lean. I did find an article from a Mike Hoffmeister that seemed to point this out. Also, I believe you may think this is the 110 because you mentioned a regulator adjustment which on this one ,( the 115 ), is fixed. Gonna run it again this weekend.

Wild Beat

Yes of course! I forgot that the 1.15 has a different regulator assembly. My settings were for the 1.15 in any case. Overall your engine seems to be running on the lean side, make sure as I said that it's got a good smoke trail in flight and that it doesn't overheat.

flyitrite

Will do that when I run it again on Saturday I hope. Plan to check rockers again now that it's had some good run time. Thanks Wild...

los36

My Feedback: (1)

Did you ever get your engine running correctly? I have a 115s that is behaving similarly. After a short period of bench running for break-in, my first 2 flights were good. Since then, it's got an intermittent midrange stumble on the ground. When it seems to have cleared itself up, I take it up and the stumble comes back within a few passes resulting in a deadstick landing ... usually off-runway.
Nothing obviously wrong with engine ... OS F plug, Wildcat 20/20, Xoar 16x8. I don't know my low-end air bleed setting off the top of my head, but I did set it per instructions. It will idle around 2000 - 2100rpm for a few minutes, no problem. My high-end needle is set rich as the engine is still technically in the break-in period at 2 turns out. It performs well at full throttle with a good smoke trail.

flyitrite

I did get it running. The problem was a loose receiver antenna! The plane would get a bit too far and go to failsafe which would close the throttle, then with no vibration I would get control again and would land and find the engine would start right up and run. Now for your trouble. You are remembering that the air bleed is opposite of the main needle correct? I am not sure how you tune it but YS are certainly unique in that regard. Assuming it is tuned well and not knowing many other factors, I might take a very wild guess and say try a new OS plug. I find they often go bad during a good break in. I have not checked here much but I will follow up with this for you.

los36

My Feedback: (1)

Thanks for the reply. I've actually got it running well now. I fly off asphalt, but the starting area is on the grass. I pulled the engine out of the plane and tore it down. There were little bits of grass all over it and some inside the carb. I found the air chamber and carb screws were only snug. I cleaned all of that up, cleaned out the regulator, checked valve clearance and tightened everything up. I found that I had my low end screw 3 turns out which was probably at least partly to blame for my problem. It would idle fine without climbing rpm's but I guess it was too lean. Based on all I had read about YS in general, I thought the low end screw had no affect above 1/4 throttle. I then read something about the 115S low end screw affects up to 3/4 throttle. I'm not sure what to believe, but obviously it's more critical to overall performance than just a reliable idle.

flyitrite

Good to hear it's running. I have a process I use to set both needles and when it is completed I have found these engines to be superb. About the low speed, it is really effective when the throtttle opening or throttle position is nearly closed. This could be a range of rpm due to other factors and if it is rich or lean then the effects carry over into high speed until that needles' settings take over. That may be a moment or two. When these engines are tuned well and running they have no equal. Got to go to the field now, drop a line if I can help w/ anything.

slembones

My Feedback: (1)

the low end needle on the 115 effects only the idle. nothing else. if you get the engine a bit too rich on the high it will load up at mid and low throttle and the engine will dead stick. you have to set the needle just right. pretty much at peak maybe one click rich. no more or it will die in the middle. flown mine 100 times best engine ever.