Hi All,

I have YS 110 that I'm running with a 16x4 APC on 30% CP and I'm having problems setting the idle on the motor. The high end is 9000 rpm, the transition from idle to full throttle is excellent; however, when I throttle back to idle I can't get a consistent idle. When I adjusted the high end I went to the max RPM and then backed off of the main needle about three clicks.

The motor will drop to 2200 rpm and go down as low as 1650 and come back up to 1850 rpm. I can't get the motor to drop to 2200 and stay between 2200 and 2000. I've tired leaning the idle mixture out as far as four turns, starting at 1/2 turn and opening the screw (counterclockwise) 1/8 of a turn at time.....needless to say that took a while. All idle adjustments were made after I throttle up the motor and was bought back down to an idle. Also, I installed a new glow plug. When I pulled out the old one it looked black as if the motor is running rich; however, the motor does not load up.

The altitude here in Palmdale, Ca is 2480 and with temperatures in the high 90's the density altitude is about 4000 feet.l

What I've done to date: I went to the YS performance web site and set motor according to the instructions:

I used the regulator to richen the transitions. It was opened 1/4 of a turn

I brought the motor up to 3500 rpm to ensure there was no surging, thinking this would tell me the regulator is properly set. There is no surging.

The idle screw is now set about 2 3/4 turns out.


If anyone has any recommendations or if there is anyone in the Palmdale area who can assist me in tuning the motor, I'd very much appreciate it

Regards,

Chuck

You won't be able to fix it on your own. It will have to come in so that we can do it. Please send it back.

Sorry for the problem.

To YS Performance,

I received my engine back from you today. I'd like to thank you and Larry for the all the time you spent on my motor. I put it on the bench tonight, Damn it runs great. Can't wait to see what it's like when it's in the air.

Regards,

Chuck

Please keep us informed.

Thanks, and Good Flying!

Dave,

Again, thanks for the Customer support!!!!!

Over the weekend I flew the Funtana 90 with the YS 110 with a 16X6 prop and 30% CP. I accomplished 3 flights and the power in this motor is great. The transistion though out the power band is awesome. Since YS installed a new bearing, ring etc., I made sure the motor was running rich. The idle is 1000 % better than before. It did flame out on my last fight while on approach and I believe it's because I'm running everything rich. I'm going to lean the idle mixture a bit and see what happens.

Since I'm not really familiar with the YS four stroke I'm very carefull when making any adjustments to the motor because I don't want a lean condition. Is there anyone you could recommend in the Palmdale area that has a thorough understanding of the YS four stoke that I could hook up with and double check my tuning?

Your response is greatly appreciated.

Regards,

Chuck

Sorry, I don't know of anyone in your area. Go easy and you will figure it out.

Good Flying!

Dave,

The idle mixture was rich by one full turn. The motor at idle, purrrrrrrrrrrrrrrrrr's like a kitten

Thanks for all your help!

Regards,
Chuck

Good Flying!

Dave,

Engine is great and I'm flying it a bunch.

How often do I need to adjust the valves? Will the motor's rpm's drop when the valves need adjustment?

Thanks for your help.

Chuck Mosa

Check the valves every 40 to 50 flights just to be sure.