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YS 120 general questions

Old 05-19-2008, 10:06 PM
Troy Newman
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Default RE: YS 120 general questions

The engines operate basically the same....The "E" clip retainers are fine. You should replace them anytime they are removed. Its not that big of a deal....The newer style is better but the old style works for many many moons. Its definitely not worth buying a new head at $130 for a new head assembly to get the new valves and head. You can buy lots of the "e" clips for that price....

I would say change the E-clips about every oh....300-400 flights and then you will not have a failure. In fact you can make it much longer but this is a safe time frame and is usually about the time the engine might need new bearings and a ring. Depending on how much you fly this could be a year or several years.

We can diagnose the specific model you have....YOU DO NOT HAVE A 120FZ.

I'm in process on doing some photos on the differences...

If the engine has a big square box on the back like the 110's then it is a 120AC.

If the engine has an air bleed mixture adjustment screw on the throttle barrel on the needle valve side then the engine is a 120SC or a 120FZ....since it has the e clips its not an FZ so you would have a SC.

The 120NC and the 120SF are the tough ones to tell I said above.

Try going here for some info on setup and operation. Any of the YS manuals will work. Like your 120FZ manual. The only difference is you don't have the low speed air bleed screw. So the idle and midrange adjustment are both done with the regulator. If you have a problem with there we'll discuss it more.

here is a site with some details that will help you.

Troy Newman
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Old 05-22-2008, 10:28 AM
Join Date: May 2008
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Default RE: YS 120 general questions

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