ys two stroke problems
 

I have a ys 45 and a 60 my problem is that my ys 60 the fuel inlet fitting is close to the carb and the pressure is at the fitting close to the prop hub it idles perfect and runs flawlessly all the way to 3/4 wot but full throttle it falls like its not getting full and cuts off. Now my ys 45 is the opposite far as fuel and pressure lines go and runs perfect. but the 60 will not run with the lines reverse (Like the 45). The 60 was rebuilt by YS a couple of months ago I recently installed the motor on a PC-9 and had nothing but confusion since. I'm running Wild cat 20/20 fuel, using a OS #8 plug, exhaust is a mac 1160 tune pipe trying to turn a 10x10 apc prop.

RE: ys two stroke problems
 

I just looked at my instructions and the 60 is the front (close to prop) is fuel from tank and the rear is the pressure to the tank. Make sure the check valve works. aLSO TRY AND LEAN THE NEEDLE valve a little at a time. Mine is about 1.25 turns out. If it is 2 turns out it will not run past half throttle. Good luck.

RE: ys two stroke problems
 

Ask Dave Shadel at the YS Engine Manufacturers Direct Support Forum.

RE: ys two stroke problems
 

My 45 is like that but the 60 will not run with the lines like they are suppose to be only the opposite way

RE: ys two stroke problems
 

BE advised, pressure is the REAR fitting and must be connected to the tank VENT fitting. A check valve must be installed in the fuel line between the fitting and the tank. THe check valve must be installed with the direction of flow such that pressure can be applied to the tank but not allowed to exit the tank. YS recommends only 2 prop sizes: 11x7.75 or 11x8, the header length should be 3", your 1160 pipe and glow plug are correct. THe diaphram regulator screw on the bottom of the engine adjusts the low speed and initial setting from the factory is with the screw flush with the regulator body - adjust clockwise for lean and counter for rich. THe high speed needle initial setting is 3-turns open although mine will not run well above 1.5 turns.

RE: ys two stroke problems
 

Hi, where can i found tune pipe for my YS 45 engine ?

RE: ys two stroke problems
 

I have had very good results with the 2C46F80 ES Composites tuned pipe. It is light and quiet compared to the other pipes I have heard.

http://www.escomposites.com/2%20cycle.htm

The ES Composites 2C46F80 pipe appears to provide a wide power band. If you want nothing but highest possible RPM for racing then you might want another pipe. Using the 2C46F80 pipe, I bench ran a YS 45 rear exhaust with props as big as 11x8 (@12K+ static). I currently run the rear exhaust YS 45 and 2C46F80 on a Venus 40 with a 12x5 (13K+ static RPM). Very good thrust and good speed for acro. The header run I need for the Venus keeps me from experimenting with higher RPM (speed) setups.

RE: ys two stroke problems
 

i want to put YS 45 engine on Diamond dust plane, it will be good on this airplane? or i need ligh wieght engine for this airplane?

RE: ys two stroke problems
 

--------------------


The YS .45 isn't THAT heavy. Just move the battery and servos back to balance the model.


Ed Cregger

RE: ys two stroke problems
 

Thank you very much Ed Cregger ... :-)

RE: ys two stroke problems
 

How are you measuring the length of header pipe (starting point).

RE: ys two stroke problems
 

Hello, I am having some troubles with my YS 45. The plunger,diaphram,and gaskets have been replaced by me. It seems to behave fine but has a tendency to "flame out" at throttle up after an idle making it unreliable. Works fine one time and when you think all is well, it just stops on throttle up. Check valve and tank hold pressure all day long. Regulator is maybe 1/4 turn lean, and needle valve is 2.25 turns out. Any thoughts on what to check or recheck?

Ken

RE: ys two stroke problems
 

That sure seems heavy for a Diamond Dust.....but I've only seen them fly and haven't built one.

RE: ys two stroke problems
 

Ken!

If it was okay after your repair you should check diaphram unit casket. Small holes used to be too small and had some offset also and in use the edges frayed and blocked fuel flow. Fraying seemed like resin broke off and casket fibers were left sticking. You fight have a foreign object somewherw in needle or pump unit. Did symptoms happen suddenly of did it go worse in time?

Also sometimes silicon diaphram goes bad and swell like a cup. Mineral afterrun oil does that.

RE: ys two stroke problems
 

Hello to the R/C flyers in Finland!

I will check the gasket hole size and alignment. Diaphram,plunger and gaskets are brand new. Compression is great. Bought engine used in a Sig Something Extra and was checking it out before flying it. The "flame outs" are eratic. Engine seems to do fine, then just fails to throttle up sometimes.

Ken

RE: ys two stroke problems
 

Check the little 0-ring on the needle. Your needle being over 2 turns out seems a bit much. My .45 and my .60 are like 1.75 turns out. If the needle is a just a bit too rich, it will flame out when you try to go full bore.