Hi,

I have a YS 1.10 with a Hatori pipe mounted in a Swallow pattern plane. I'm running the new low viscosity Coolpower oil 22% with 20% nitro, and a 15x8 APC prop. The ambient temp was about 35 degrees Centigrade.

The engine seems to overheat, both at idle on the ground and in flight. I noticed it losing power on the last flight.

I decided to try to run it without the cowl to see if that improved the problem. The engine then promptly detonated and threw the spinner.


Do I need to strip the engine to check for damage? How would I recognize heat damage? Any idea's for a fix?

Steve

It sounds like the engine is getting less fuel than it needs. I had it happen several times. (Throwing prop). The engine did not get hurt. It turned out that the regulator gasket was distorted. Fitted a new one and the engine ran propoerly.

If you have compression and no crunchy noises it should run again..

As mentioned before it may not be getting enough fuel.
But,
I just bought a YS 1.40 for my plane and it WOULD NOT run worth a flip on anything less than 30% by volume not weight % Nitro. I was running Byrons 25% (for 1 flight). The engine was sluggish bigtime in the air and when I landed it the exhaust pipe was blue. A fellow pattern flyer had some Magnum 1.5% (approximately 30%) and I emptied and refilled the tank. The engine fired right off and flew the plane like a scalded banshee. When I landed the head was MUCH cooler and the so was the exhaust pipe. I was promptly educated on YS engines by the pattern guys there, and I saw it for my own eyes. YS 4 strokes must run good high nitro fuel or they overheat. Cool power is great fuel, you may just try higher Nitro.

I would also say if it turns over smoothly and has good compression its probably not hurt. I would try to run it as I mentioned above.
Thats not gospel, just my opinion.

It may also be possible that you got some bad fuel. May'be you should try a different to fuel, atleast that way you can eliminate, that it is not the fuel causing the problem.

It sounds like it's running too lean. Overheating and throwing props both say it could be.

The exhaust valve would be the first to go if it has cooked too much, and that can be checked by seeing if you have good compression. If you have, it should be OK. Also, check the valve clearances to make sure the timing isn't off.

-David C.

It could be too lean.
I would guess 1 1/2 to 2 turns on the needle valve should probably be pretty close, and turning maybe,, 8700-8900 RPMs with a little smoke in the exhaust once its broken in. What size prop were you using?

15x8 prop is too small - over revs.

Ground it -----------Get OS 140 RX eFI

You have a lean running engine.
I would recommend that you have it checked out if possible.
If you have flown it in this condition a lot, you could have damaged it.

If you are running a fuel filter the filter clogged. Pull it and try running the engine without the filter.

Sam

Note: I should have said "could be" clogged. It is only a possibility not a fact as I have written it above.

Excellent point!



-David C.

Did someone forget to mention fin cooling area. With 30degrees C ambient, you have to make sure there is enough air flow past the head. I am not sure if the Swallow is enclosed cowl or not. Also check for correct valve clearances. .05mm on cold. Plus ofcourse fuel flow as mentioned by several posts above.
I only fly YS engines (all darn Eric Henderson's fault, he introduced me to them, nothing else seems better).

PineBaron
PineBarons R/C Club South New Jersey.

I have the 110 in a ZNline Synergy 90. When first installed and new I had a lot of coolng problems. Answer open up the cooling slots. Rember the exit need to be twice the area of the imput holes. Also the engine took along time to bed in. I guess I used about 1 1/2 agallons to break it in. I also run it rich, donot rember the settings but the engin was peaked with a tacho and then the needle backed off about 1/2 turn. I think on 20% nitro I wa getting 9 to 9.5K from a 15 x 8.

Good luck

Kris

Another point. These run hot until well broken in. The only YS that I will run in on the airplane are the 140L and DZ and the 63. The 110s, 120s, and sport 140 should receive their first gallon on the bench or at least, if you do not have the bench or will to bench run the motor, fly it without cowl. Once broken in they cool off markedly.

One other point. We went out on one of these hot as heck days and even the seasoned, well broken in motors simply did not want to even out and run well. The only solution here is to really open the intake and outlet for the air. On the hottest day we flew, all motors complained, from the YS to the big DAs.

Mark

Mark

inlet opening is not that critical - critical is the outlet area - it should be at least twice if not three time the size of the inlet. If you want to keep outlet area small, just make a smaller inlet area (caution : this is only possible to a certain extend) The big problem encountered are mainly caused by the fact that hot air can not evacuate quickly enough...

Alvin