YS-120SF VS YS-120NC
03-06-2012, 07:40 AM
#1
Thread Starter
My Feedback: (3)
Join Date: Sep 2003
Location: Port Allen,
LA
Posts: 93
Likes: 0
Received 0 Likes
on
0 Posts
YS-120SF VS YS-120NC
Petec
I would like to get an idea what the performance difference is between the 120SF and 120NC. I have one of each. The SF (YS-0070) is installed in a CG Sukhoi SU-26MX and has been in storage for about 5 years. (Cleaned and oiled it up really well before I mothballed it). The SF ran really well and I loved it in that aircraft! The last few times it ran, the needle valve was extremely non-sensitive. I did not really notice much difference between 5 turns out and 2 turns out but it still ran well. I stopped flying that airplane because I was leary of the change in engine tuning. I had planned to go through it and try to diagnose the problem but other priorities took me away from RC so I mothballed all of my stuff. I have recently resurrected my RC activities and want to get all of my stuff up and running. I also have a NIB 120NC (YS0074) and I want to install it in a CG 10-200 Ultimate BP. The SU-26MX is about a pound heavier than the Ultimate BP. I am trying to decide which engine to put in which aircraft. Depending on the difference in performanc between the two engines, my inclination is to send the SF to you guys and let you go through it and install the NC on the Sukhoi. When I get the SF back I would install it on the Ultimate BP. Since I'm thinking about sending the SF to you guys, what are the updates, if any you would recommend for that engine? Same for the NC. I may send it to you also depending on any updates you may recommend for it.
I would like to get an idea what the performance difference is between the 120SF and 120NC. I have one of each. The SF (YS-0070) is installed in a CG Sukhoi SU-26MX and has been in storage for about 5 years. (Cleaned and oiled it up really well before I mothballed it). The SF ran really well and I loved it in that aircraft! The last few times it ran, the needle valve was extremely non-sensitive. I did not really notice much difference between 5 turns out and 2 turns out but it still ran well. I stopped flying that airplane because I was leary of the change in engine tuning. I had planned to go through it and try to diagnose the problem but other priorities took me away from RC so I mothballed all of my stuff. I have recently resurrected my RC activities and want to get all of my stuff up and running. I also have a NIB 120NC (YS0074) and I want to install it in a CG 10-200 Ultimate BP. The SU-26MX is about a pound heavier than the Ultimate BP. I am trying to decide which engine to put in which aircraft. Depending on the difference in performanc between the two engines, my inclination is to send the SF to you guys and let you go through it and install the NC on the Sukhoi. When I get the SF back I would install it on the Ultimate BP. Since I'm thinking about sending the SF to you guys, what are the updates, if any you would recommend for that engine? Same for the NC. I may send it to you also depending on any updates you may recommend for it.
03-06-2012, 08:39 AM
#2
RE: YS-120SF VS YS-120NC
The NC makes more power than the SF, so if you are looking at a strict power to weight ratio the put the NC in the heavier plane.
There are no real updates to the engines, but if the needle is not responding that can be a number of issues. First I would look at the actual needle itself and make sure it isn't worn, this happen mostly when an extension is put on a cowled engine and the needle rocks a bit more due to harmonics of the extension. The taper of the needle gets a shoulder worn into it and the seat as well. Barring that and given its age a trip to Richard and his crew might not be a bad idea.
There are no real updates to the engines, but if the needle is not responding that can be a number of issues. First I would look at the actual needle itself and make sure it isn't worn, this happen mostly when an extension is put on a cowled engine and the needle rocks a bit more due to harmonics of the extension. The taper of the needle gets a shoulder worn into it and the seat as well. Barring that and given its age a trip to Richard and his crew might not be a bad idea.
03-06-2012, 09:32 AM
#3
Thread Starter
My Feedback: (3)
Join Date: Sep 2003
Location: Port Allen,
LA
Posts: 93
Likes: 0
Received 0 Likes
on
0 Posts
RE: YS-120SF VS YS-120NC
Thanks Petec.
Actually, that engine DID have a long music wire extension on it to extend it beyond the cowl on the Sukhoi. I now remember ordering a new needle valve for it before I mothballed it but never installed the new needle valve or ran the engine. I'll replace the needle valve WITHOUT the extension and run the engine. If that fails to remedy the problem or if there are other problems that crop up, I'll send it off to Richard.
03-06-2012, 05:02 PM
#4
RE: YS-120SF VS YS-120NC
If the needle by itself makes a difference order a new seat too as they wear in a pair. I learned that the hard way before I was a Team YS guy, if I remember correctly there was a cable extension that Central used to sell that would help alleviate the issue if you must have an extension. My fix was an allen head bolt small enough to fit in the hole in the needle valve and then I'd use a long ball driver to make adjustments.
