YS engines are easy to take care of. At www.centralhobbies.com there may be some stuff on maintenance, also the pattern forum here on RCU has some really truly knowledgeable YS guys.

They really require nothing different than a typical 4 stroke. Just set the pressure regulator screw (Big Brass Screw underneath) flush with the engine case and it will be fine. After that its no different than any other 4 stroke. Just the occasional valve adjustment which is super easy if you just follow the instructions that come with the engine. I dont check my valves but about 1 time every 50 flights or so and then I usually do not have to readjust.


It should be this way from the factory anyway. I fly pattern and we are constantly around lots of YS engines. I see needle valve adjustments, occasional plugged check valves/fuel filters in the fuel lines( which can cause it to go lean, remember to check your check valve and fuel filter anytime the engine seems to be leaning out) problems due to bad fuel and heat issues when it gets above 95F outside, but never is the pressure regulator a problem.

Sometimes you may get a little trash in the regulator, but rarely. All you do is note the position of the adjustment screw, remove it and clean up the regulator parts and the little port. Then put it back just like it was and go fly.

All that being said, I have 2 1.40 sports and a 1.60DZ. Now that they are set (after break in) I never touch the needles or anything unless its to richen it up slightly on a really hot day.
They really do run great and make a ton of power.