i just purchased my first ys and i haven't been able to make it work too well. i'm still trying to break it in. first the idle is all over the place, it wavers a for about half a minute then cuts out. that's just the beginning. the ys backfires so violently that it shredded by spinner and hurled it across the field. i've also experienced a huge clank when the engine siezed. now i'm nervous to run it again. are these experiences "normal"? what can i do to make it work? i am using 23% nitro spinning a 12 x 6 prop. My friend said i should consider running either lower nitro and smaller prop (which i don't think is necessary) or adding a shim to lower the compression rate (which i also don't think is necessary).

i love my 4-5 ys63's and had np with them. be sure your tank is set up rock solid with everything tight and no air leaks. set yur high speed needle to 1/8 turn richer then spec says. don't adjust anything else and by all means tighten your prop up...don't be afraid to tighten it. start the motor up and only adjust the high speed needle at high end....leave it rich a bit they love running rich. if thats a 12-6 APC prop it's fine. i use w---cat 20-20 in mine and they run great.[8D]

Yea, make SURE it's not lean...

YS Engine DO NOT LIKE to run lean.

thanks... i will try that! i didn't think that i was running lean... but i will take your advice and run it rich rich rich!

Sounds like the low end is lean. Lean the low end by turning the the low end in about a half till it gets rich. The low end on YS motors are oppisite then the high end.

Also check the regulator. Make sure it is flush with the housing.

You may want to break in the motor in the air. Or it will get too hot. Run the motor rich and fly around at half thr. for about 5 mins.

Make sure the fuel has 18%-23% oil. More the nitro the more oil you need.

Mike

thanks mike. what do you mean by "flush". the regulator now sticks out about a millimeter from the housing. i know the instruction says that it should be flush, but i was not sure exactly what it meant. i didn't want to be changing anything and hoped that the factory would've set all of this prior to shipping... i guess this isn't the case.

tinman - yes, it's an 12 x 6 APC. recommended by the LHS for breaking the ys in

You should be able to run you finger over the regulator and it should feel smooth. I.E. Flush
This is a good starting point. And it should run at that setting.

Also when adjusting the high end go one click and wait ten second. YS run with pressure so it will take a few seconds for the change to happen. Also pinch the line for a second the motor should pick up some rpm. If it does not them you are to lean. Do this on the high and low end.
An APC is a good prop for this motor.

What kind of fuel are you using? You need 20% oil. If you do not have at least 20% oil you will burn it up. If I was you I would try Cool Power 30% Heli fuel. I have been use it for 3 years now and it works very well in all my YS motors.

Mike

If you have dirt in the rgulator it will give you a fit.
You need to run a filter on the YS to keep dirt out.
I have had 2 ys engines to do this and i called tech support
and both times they said i had dirt/silicone particales in the fuel regulator
and sure enough thats what was wrong. I cleaned it out and everything
worked fine.

thanks, i'll try all of those things. unfortunately, i can only fly on the weekends so the misbehaving ys will have to wait :-(

Since this is your first YS, make sure you did not connect the lines backward. Another word, make sure the check valve is in the pressure line (left side of the engine when viewed from rear) and that the check valve is facing in the right direction. Use a fuel filter between the engine and the check valve to prevent crud from clogging up the check valve. Use another fuel filter in the feed line between the tank and the engine. I had four YS .63's, and none of them backfired or threw a prop on me. You should be fine if you are not running your .63 too lean. The regulator screw is there for you to tune your midrange. If you slowly advance to half throttle and the engine begins to load up, then you are too rich on the midrange. Turn the regulator screw clockwise 1/8 of a turn at a time until the engine stops loading up. On another hand, if you slowly go to half throttle and the engine begins to detonate, then you are too lean on the midrange. Turn the regulator screw out 1/8 of a turn at at time. I get great results with Powermaster YS 20/20 fuel.

Thanks Richard,

Actually, I have a question on the regulator. Where is it? I thought I knew where it was but now I'm not sure. Could you describe it to me. The manual I have doesn't point out the regulator. Thanks!

that is that large screw you see on the engine...it has a slot for a flat blade screwdriver. these are preset at factory and i wouldn't mess with that until last resort. if your motor is new i would just set high end needle to 1/4 turn more then manual says (1 1/2?) and start it. you are supposed to adjust the motor when wide open with high speed needle only also. when it is correct you should be able to chop the throttle and it will idle (adjust with radio)perfect. be sure ya have yur tank full and the tank vent capped off with a removable plug. after running remove plug to depressurize your tank. these things run rich so let it smoke a bit and it will run just fine...[8D]

okay... I'll give it one last shot with all the suggestions. I'll leave the regulator alone until I have the high and low end tuned in.

I recommend that you ask Dave Shadel in the YS Manufacturer Support thread. http://www.rcuniverse.com/forum/YS_E...mid_197/tt.htm

I tried it out again and to my dismay... it was still strange. It just wouldn't settle down. And at higher rpm (had to run it a little higher rpm at times to prevent it from stalling) it had a light but sharp mechanical clanking that scared the heck out of me. I have since replaced the ys with a .61 Tiger Shark engine. Upon removing the engine, I realized that there was a leak from the fuel line. Also, the dubro kwik fill fuel valve may have an air leak. Would this explain my ys63 "idling" at 5000+ rpm or that clanking sound at higher rpm?

On a completely different note, I moved from using cosmo aerostar 23 to coolpower 20 on my OS FS30 and can I say that the power differential seems quite startling? Idling, especially has required much more throttle to maintain. Is that normal?

Never use those quick fueling valves on a YS engine. Those fueling valves might not be able to stand up to the pressure in the fuel lines. I always use two T's and two fuel dots:



The sharp clanking sound that you heard was detonation. The engine was running too lean.

No offense but this is what happens when you dont buy a Saito

That'll open a can of worms.

maybe, but it still is true

Some people just like picking fights...

Some of us like to tell the truth

well its obvious his air leak is most likely the problem. i have saitos and i also have 4 of the ys 63's....and i must say the ys 63 is a great motor....

thanks for the advice... i will try to hook up the ys63 on a bench this time and run it in without any unnecessary connections. (fingers crossed)

Richard, in "detonation" i'm hoping that you are referring to something normal and not that i just blew up my motor. I haven't done any permanent damage, have I?

Regarding Saitos... I was looking around for some but I could never find them in Hong Kong. Then I went to one of my LHS and, to my surprise, he had a Saito .50 gk. I know that the .50 is an "older" engine but the price was decent $160. The problem was that it just didn't look that high quality. Compared to the O.S. and the YS I just didn't get that sense of fine engineering. The castings (maybe due to the black coating) just didn't seem "precision". And the GK finish that looks so good online, just didn't do it for me in real life. I swear that it looked like a Chinese knock-off more than a Japanese lump. Anyway, I was running over town looking for a Saito .72 but now... i think i will end up back with O.S. Of course, I will try to get YS63 running and broken in. I think it is the perfect engine for my Corsair F4U. Just if the darn thing would work!!!

The truth about what? The truth that Saito's are inferior engines?

I wasn't going to say anything, but oh well. I used to have two Saito 72's. One was the regular silver version, and the other was the Golden Knight version. They both required a significant amount of break in time (3 gallons of fuel each) before they were able to achieve a reliable idle inverted. The highest rpm I could get out of them was 10,000 on a 13x6 prop. Needless to say, they were replaced by a couple of YS 63's. Both YS 63's achieved rock steady idle inverted only after two tanks of fuel, and both peaked out at 11,700 rpm on the same 13x6 prop.

Here is the ground rpm on a YS 63:



Yep, that's 11,300 rpm rich on a 13x6 prop.

Gotta love these:



I would never go back to Saito again.