YS 120 gets hot.

[haha]

OK so I just got my ys120 back from ys and im in the process of breaking it in. I/ve gone through 6 tanks now where the needles were at 2.5 high and 2 mid ( i just want to run it rich). So i started to lean it out yesterday and i got significant increase in power but the only problem i got now is the motor gets really hot. If my high needle is at 1.5, at which the motor is not as hot, the motor produces no power at all; however , if i lean the needle to 1.25 i get " ok" power but the motor gets very hot. What should i do now? Even at 1.25 i can still see some fuel dropping out of the muffler so i know i can lean it more but i dont want to do it because is too hot to touch. I;ve watched tim jones tunning videos and he says not to measure temperature when tuning but it is concerning.
Please help.

[jwatts007]

Try opening the idle as far as you can...see if you can get it ticking over at about 3/4 open or even 1 turn if possible....

[Bobs]

I'm at approximately l.5 turns open on my high speed needle, temps are right around 200 degrees, still runs rich and has gobs of power. Mid range needle is open around 1 3/4 and the low is about 1 turn open. I'm running Wildcat CY 30% nitro fuel.

[aviator493]

It sounds obvious, but please check all plumbing because this motor will cause air leaks. I put a small extra piece of fuel tubing over all connections especially the tank. You may not see the leak but your symptoms are there. Ive also learned that 1 click can go from kinda rich to pretty lean. Go back to 2 out on high and mid and slowly tune mid until perfect the do some very high climbs to tune the high.

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[haha]

Originally Posted by aviator493

It sounds obvious, but please check all plumbing because this motor will cause air leaks. I put a small extra piece of fuel tubing over all connections especially the tank. You may not see the leak but your symptoms are there. Ive also learned that 1 click can go from kinda rich to pretty lean. Go back to 2 out on high and mid and slowly tune mid until perfect the do some very high climbs to tune the high.

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ok, will check for leakage this weekend.

[aviator493]

Especially where pumped air enters tank! That cured my inconsistency and even helped with bubbles in the regulator to carb line.

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[Goodlett]

My 1.20 is pretty hot on the back plate. I just tune to where it runs good but puts out plenty of continous smoke. So far so good, i got probably 6 cases of fuel through the motor. I can hold my finger on the back plate for ten seconds but start to scream at 8 seconds.

[haha]

Originally Posted by Goodlett

My 1.20 is pretty hot on the back plate. I just tune to where it runs good but puts out plenty of continous smoke. So far so good, i got probably 6 cases of fuel through the motor. I can hold my finger on the back plate for ten seconds but start to scream at 8 seconds.

what is you needles setting? like 35-38 clicks from completely close?

[Goodlett]

I was just flying and didn't think to measure temps. I'll count clicks and be back.

[whittb]

I had the same issue. My YS120 sounded extremely rich and smoked like a freight train, but it would run to hot if I tried to lean out the needles. It’s a very difficult motor to tune. I had some of my local Nitro pilots help me tune it and by the time we got the motor sounding good and producing good power, it was coming down at 220 degrees. That’s too hot.

My 105HZR is a lot easier to tune and makes good power. The YS120 is a lot stronger. But I will stick to my 105.

My YS120 is a paper weight at the moment. I am in need of a piston pin retainer and they are not selling them at the moment. I have called and Emailed them with no response. I guess that means they are out of stock. I will keep the motor as a backup just in case, they are worthless on the for sale forums anyway.

[G200driver]

whittb,

Shoot me a Pm...I just had a piston blown apart on a YS120...Instead of fixing it, I decide to just buy a new YS 120, one that I know the complete history of...anyways, if I have any parts that might help you, I'd be glad to hepl out till new ones become available..

Jim

jsfowler@catc.net

[jwatts007]

I use the gudgeon clips out of the YS 90s G shaped and easier too install and get out, the C clips are a pain......

[whittb]

I considered using a clip from another engine, but they do not completely fit inside the small grove on the YS120's piston. I have a friend at my local field that lost his engine when one of the clips he re-used came out during a flight.

[haha]

looks like YS have to rethink their strategy.

[jwatts007]

I am sure they 90 sized clips fit ok it is reusing them that may cause a problem if they are out of shape...
All my mates have 105s so I have not got anyone I can compare mine with, but I am sure they need plenty of fuel through them before they can be leaned out and tuned for full power...

[jgalen0025]

Originally Posted by jwatts007

I am sure they 90 sized clips fit ok it is reusing them that may cause a problem if they are out of shape...
All my mates have 105s so I have not got anyone I can compare mine with, but I am sure they need plenty of fuel through them before they can be leaned out and tuned for full power...

that is wrong the os 105 can be leaned out after a few tanks, this coming from a rep and a couple pros at the field and me!

[aviator493]

Originally Posted by jgalen0025

that is wrong the os 105 can be leaned out after a few tanks, this coming from a rep and a couple pros at the field and me!

To be honest I fly one tank at factory recommendations then by 5th-8th flight I'm damn near tuned on all my motors! Seems to work fine for me!

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[Matt Nasca]

By the end of gallon number 2, my YS 120 was tuned and running strong! Many cases later, it's still a stump puller, with just a couple clicks change here and there for temperature changes.

[haha]

what is a good temperature rang?

[Goodlett]

I remembered to check my settings this weekend;

Mid 42 clicks
High 45 clicks
Rotor Rage 22.5%
Enya #4 plug
Hatori pipe
Gov set at 16400 rpm
Ambient temps 90 F
Temp just under head immediately after hard flight 180F
Max temp on head 197 F
Backplate feels hot but can hold for 8-10 seconds
Plenty of smoke
Lots of power

The last two comments are pretty subjective but the 1.20 has much more power than my OS .91 Hzr.