YS 120 problems
 

have a YS 120 that has about a gallon of fuel through it and all of a sudden it will not run (for very long). It primes and then it starts and If I give it throttle it seem like somthing is lugging it down and then it slows and dies. I have check the fuel lines, cleaned the fuel filters and checked the check valve and still the same thing..then I made the mistake of turning the pump screw ...took it out and it appeared clean. Now it is way out of adjustment and will not hardly start. I have not touched the low end so should be good and I have the high end at 2.5 turns out. I notice that when it runs I can see fuel going to the front of the right side of motor and then when I throttle up the fuel seems to get pushed back. The fuel tank does not seem to be getting any pressure built up either...I have lost my manual.

Any help would be appreciated..

thanks

Dunk

RE: YS 120 problems
 

The starting point for the regulator screw is flush with the housing.

If your fuel system isn't holding pressure that is a big issue that needs addressed. Is the check valve in pointing the right direction and is it functioning properly. If you blow through it it should only allow airflow inone direction and that direction is toward the tank.

Are the fuel lines ok? Is the tank stopper ok?

Which 1.20do you have? I have a lot of manuals in PDF format and could e-mail you a manual if I have it.

RE: YS 120 problems
 

Check the "Tee"s in your fuel lines, and all your fuel fittings, for leaks. Often, the fuel line will get a very small tear in it right where it goes over a barb, that could also cause the loss of pressure.

RE: YS 120 problems
 

It is a F-120. I think I am going to start to replace all the fuel tube and then start from there. A manual would be helpfull. The more I think about it the more it seems like it was leaning out as I increased the throttle. The start of my problems was that the fuel tank split...should have used a seamless tank...I will adjust the regulator to flush and see what it does.

thanks

RE: YS 120 problems
 

If you swapped your tank out when it split you might have put a small nick in a fuel line.

PM me your e-mail address and I'll send you a manual if I have it. I need to check my other computer.

RE: YS 120 problems
 

Link to YS tips and manuals...

http://www.geistware.com/rcmodeling/...ys_engines.htm