I have an old but brand new ys 120F, I am thinking of putting it in my Funtana 90. Can anyone tell what the performance of this engine is like compared to the other YS 120 models i.e. FZ etc. ?

Thanks

Paul.

You will get between 9700 and 10100 on an apc 15X8 prop. I usually got mine to about 9800. This is almost identical to what the 110FZ puts out, whic is the ultimate engine choice for the funtana. However, many people claim the need for more weight up front, so your 120 os a good choice...you will want to run an apc16X6. BTW, this is the same engine that Kyle used in his video. If you haven't seen it, here's a link...
http://www.kyle.macapple.com/Videos/...ueen-small.wmv
BTW, he said he thinks it's a 120FZ. Nonetheless, if you keep it under 9.5lbs you'll be fine.

The YS 120 is the engine I am running on the EF Yak 68" and it is very good. The extra weight helps balance the plane with out a problem, far better tha using PB dead weight.

I am finding that the 16 x 7 APC is about right for freestyle and 17 x 6 apc for 3d. I also have an adrenaline 120 with a YS110 in it, As Bodyworks states the RPM and power output is about the same for both engines. I would however run the 120 at lower RPM as it is not as rev'y as the 110. I would prop for about 9000 to 9500 on the ground. One thing though I find that the 120 is more torque-y than the 110 and as such has less trouble swingging a bigger prop.

You will need to run 20% or higher nitro fuel though to get the best out of any YS four stroke. I have used 30% but don't see the need as 20% has plenty of power.

Hope that helps

Kris

Thanks guys, advice much appreciated. Will go ahead and finish it now

Best Wishes

Paul

I have a used YS 120 F that I recieved from an associate. He stated that it has been run maybe 1 hour flight time. It does sound good, "However" upon trying to fine tune it, I can shut off the mixture control completely and it will still run at full rpm and on high idle. It runs better at 1/4 turn open. (stops popping) When I go to idle at approx 4500 RPMs, it slowly comes to a stop. if I increase the throttle, it dies immediately. I have tried to adjust the idle adjusting screw and find that it will operate at 1/4 open from the closed position. As long as I leave it on high idle approx 5500 RPMs it runs good with no ill effects. I don't know too much about YS but it seems strange that given the cituations, I would think that the low and High mixture controls are not right. This is a closed system with new lines and no leaks. I am useing Excalabar 25%. I have also removed the Idle adjust ment screw and the nipple looks good and the aera clean. I am running a 16 X 6 prop and the bird flys great as long as I am on high idle. I sure would appreciate some help. Thanks.

Ron

I have two of these YS 120F engines, one mounted in a Funtana 90 and the other is in a SIG Mayhem. I am using Zinger 17x5 propellers on both airplanes. These engines turn about 9800 rpm with these propellers using 15% Coolpower.

Thank you for that however that does not answer my question. Maybe you were giving me FYI. I am turning 9220 RPMs with a 16 X 6
Master Airscrew. Something is definetly wrong with my cituation
Ron

I can shut off the mixture control completely

Okay what mixture adjustment are you referring to here? The High end, Low end or the regulator on bottom of crank shaft? I have the FZ version but I'm sure they adjust identical. I pulled all my needles out before high low and regulator and got it going again. It just took a little longer than a normal 4 stroke. I can try to help out.

Oh also look at your check valve and make sure its going right way and it is not leaking. Also make sure you have it on the correct fuel line.

Also may want to get some advise from Dave in the YS engine support section. He knows YS and can get you going very quickly.

HI: I have no low idle control needle. This is a F model and dave stated that the FZ is differant. It is my understanding that the low idle is accomplished by adjustment of the regulator screw. I have no manual for this and cannot find one to download. The check valve is in the right position and no leaks any where. I am referring to the High mixture needle control when I said it can be completly shut off and the engine still runs at full RPMs with the throttle wide open. I have all the lines hooked up correctly. Dave suggested replacing all the O rings and gaskets and I have. I suspect there is a leak somewhere as it acts like an OS when there is a leak. I have seen that happen when you close the high needle mixture control and the engine keeps running. Dave stated that he doesn't have any other suggestions becaise he is not here to see it. I wish I could help you more however more conversation and we may resolve this issue. I really appreciate your efferts.

Ron