Hey guys,

My engine has almost 1 gallon through it now. I've done the valves works just fine. I'm starting to have a small problem when i turn the engine on and start advancing slowly at around 1/4 thorttle when its near 4000rmp it works roughly then can suddenly cut out. I've notice if i advance it faster towards full throttle and leave it there for a bit then idle and go back up slowly the problem is gone. This happens now every time i turn on the engine. Is this a normal characteristic of this engine? Do i need to re-adjust the regulator i have not touched it yet. The temp is upward of 30 degrees centigrade where i fly now at sea lvl.

I use ys20/20 fuel and 12x7 apc prop. The spark is new and the tank holds pressure. Checkvalve and filter everything is ok.

What do you mean by it is running roughly and then cuts out? Is there a lot of smoke and the engine loads up on excess fuel and cuts out or is there little smoke and the engine runs out of fuel?

Sounds like the opposite problem from the 110 thread that is going right now... sounds too rich on the pump. Of course, after leaning the pump, the air bleed for idle will have to be adjusted. In the engines that have the air bleed and the regulator, it is possible to have the pump set too rich, but the air bleed can be adjusted to allow the idle setting to work correctly and the only place the rich setting becomes aparent is in the mid-range. You might want to replace your glow plug first, though. Brand-new engines in the break-in period can foul a glow plug really quick due to the tiny pieces of metal floating around.

What i mean by cut out is that it cant hold rpm around 4000 then just cuts, not slows down or speeds up just as if i pressed thorttle cut. The plus was new. Im going to fly tomorrow morning ill try a new plus and redoing my needle settings and see what happens.

I was down at the flying field today and the problem got worse. The engine started loosing high end power. If i left it around 1/4 throttle it couldnt hold stable rpm then suddenly die. So i packed it up came home, i checked the valves the 0.04mm feeler passes through easily but the 0.1 does not pass. Fresh bottle of YS 20/20 fuel.

I opened up the high end needle to 2 and 1/2 rounds then slowly closed it after changing to a 13x6 prop for a lighter load and noticed i could not take the engine to its optimal rpm range and at full throttle had much less power.

What way can i use to test regulator setting to know for sure if its rich / lean and what would make the engine loose power? I'm sure i didnt run it lean and the spark is shiny clean inside no black or anything.

Anyone please...

Have a look at your push rod tube o rings, are they in place, or can you see one part hanging out, if its hanging out you have a air leak.

Will Crossman Aus

Sounds to me like the regulator is set a little too rich. The "rough" running is indicative of flooding. Usually a rich engine will just cut out after a few seconds, because the glow plug is drowning in fuel, becomes too cool to fire the fuel charge, and the motor just quits. On the other hand, a lean engine will usually speed up for just a second or two just before it quits.

The reason the problem seems to disappear after you run the engine up for a bit may be because the engine temperature is coming up, which will make it run a bit better in a rich condition. Once you get it hot, especially the head, it can tolerate the rich condition a little better than it can cold.

Try turning the regulator screw in (clockwise) about 1/8th turn and run it again. Readjust the high speed needle valve after you do, by running the engine WO, adjust for maximum RPMs, then richen it by turning the high speed needle back out (counter-clockwise) three or four turns, or until you hear just a slight drop in RPMs. If that helps, but doesn't completely correct it, do it again.

David

I believe the setting for the valves should be .02. Try tightening up the valves as well before adjusting the engine.

I'm not sure if its rich or lean, i will try opening 1/8th, if the problem gets worse then at least i've gone in the safe direction first. Thank you guys for all the quick feedback, ill try in out in 2 days when i fly again and let you know.

Troy mentioned to me in another post that the 12x7 might be too much prop for the 20/20 fuel, do you guys things i should drop it to a 12x6 and aim for 11k rpm?

When I was having trouble with my brand NEW YS 63s It turned out to be one of the o rings had squeezed out of the head where the pushrod tube fits. After fixing that, I set up up to run wide open nicely. Then got the idle sorted out. I had a mid range roughness, which per Troy's instructions I sorted out by turning the regulator screw. Turn in to lean out to rich. It should be at default just slightly less than flush with the top of the housing.

Oh, I am using Coolpower high performance Heli fuel 30% nitro, low viscosity all synthetic oil.....per Troy'srecommendaton. The regulator adjustment was just the tweak that smoothed the whole engine operation out. Prop is an APC 11 x 7

11X7 probably is too small a prop for the beast. I have been runnng 13X6 with 20/20 fuel on my YS63. Top RPM is around 8500 - 8700rpm.

That cant be right then, my engine turns 11080rpm today with tthe 12x7 on 20/20 but i fly on the beach literally.

I have a new problem now with my engine, i took of the cowl to adjust the regulator, i turned it out first 1/8th and noticed it got worse and more smokey, so i started slowly turning in a bit at a time turning the engine off between each adjustment till i got it puring at mid range. I then set the high end but the low end was ok. 2200 stable.

The new problem i have is that i noticed since i took the cowl off that the face of the engine near the tube where the pressure goes to the regulator has alot of oil on it. I did a WOT for about 30 sec the engine screemed at 10600rpm then rpm started to become unstable and i noticed the tube that connect to the regulator that brings pressure in bubbling and oil coming out and also from the bottom piece of the regulator, the plastic that screws on with 2 screws at the bottom. Also i noticed now that the cowl is off that there are small air bubbles from regulator to the carb but not from fuel tank to regulator.

Could the above problem be why my rpm have slowly been increasing even though im 2 and a half turns out on high end? today i was 2 and 3/4 and my fuel tank barely lasts 5 mins and its 320ml.

The rpm issue i've noticed it after the first half a gallon, i thought that it was because it was running in, but perhaps the engine has been leaning out before of this and now there is damage. What should i do? Should i change tubing and dissasemble the reg and redo it, or just leave it and send it in for YS service because its under warranty?

If the plastic block-off on the bottom f the engine is leaking I'd send it in. It could be the plastic is warped or an issue with the case. If it is the latter rather than the former it would have to go back any way.

The fact that the engine operated like this for a while, if this specific engine runs lean could it cause a bit drop in compression?

RUnning lean would certainly speed up wear of the ring and liner, but unless you flew it VERY LEAN for a couple gallons I would seriousyly doubt that the compression loss would be appreciable.

I doubt it was too lean as it still had smoke and plenty of it and it wasnt very hot to the touch after all the landing, i have the habit of monitoring temps all the times on new engines and this was was pritty cool considering what was going on. Despite everything this engine performs like a monster i havent seen anything like it in its size, im hoping i can get this sorted.