Sierra11861

I bought this engine used about a year ago and it has run great many times. I own 3 YS 110's so I have some basic YS knowledge. The last few runs on this one particular YS-YS 110 however I noticed that it did not rev as fast as it used to. In other words, when you gave it full throttle real fast it ran up to full power but very slowly. I blew it off and flew anyway. It seemed like the overall power was slightly lacking but the flight went ok. The today I ran it for one flight, it ran but still it seemed the power was not quite what it should be.

Then I tried starting it for the second flight and it was as dead as a doornail. I changed the glow plug, I had two back up glow starters so that was not it. I pulled the fuel supply line from the engine and fuel squirted about 10 feet so that was not it. The check valve was correct. I removed the needle and blew through the fuel intake with some spare tubing and fuel came flying out of where the needle screws into. I cleaned out the regulator and that very small silicone cone shaped part had a very slight ridge on it but the spring was there and it looked ok to me so I reinstalled it.

I turned the regulator adjustment and the low end needle all over the place but the most I would get is a slight spark, I also noticed it backfired some and wanted to run backwards a little until it died, and that was on a good turn, most of the attempts were total dead response. I checked all the bolts that hold the engine togeether for leaks....any suggestions?

wessco

My Feedback: (7)

did you set the needles back to the factory settings? Also, might want to check your fuel tubing. A pin hole will cause one to run like you're describing. Not just the tubing on the outside of the tank, the tubing on the inside also needs to be replaced from time to time.

Sierra11861

Yes I flushed out the needles. I will replace the tubing and see what happens

rcpattern

My Feedback: (45)

Make sure you change the lines on the pressure side as well.

Arch

Sierra11861

OK, THANK YOU I WILL TRY TO GET ALL THIS DONE THIS WEEKEND AND GET BACK WITH EVERYONE

apereira

To me, it looks like there's gum on the internal engine passages from the pump to the carb. Compresion is good? I'm assuming you pulled the glow plug and it was dry? did you pour some fuel from the glow plug hole just to see if it is fuel related? like on the two strokes when we were all learning??? jeje. Are you sure you don'thave a valve stuck open?

Best regards

Sierra11861

I will check all that as well. Now that you mention it the glow plug was dry

still4given

Did you try priming it? Squirt a little fuel into the carb and see if it will fire. That should tell you if it is getting fuel or not.

Jimmy Skids

My Feedback: (2)

If your getting fuel to the needle then I would think that your issue isn't fuel. No where in the thread did you mention checking valves. Have you checked to make sure you don't have a valve stuck open or to see if the valves are close to their factory settings?

Jimmy Skids

Sierra11861

UPDATE UPDATE UPDATE: You guys are not going to believe this one. You know those gold threaded couplers that sometimes you solder on the end of a 2-56 throttle push rod in order to screw on a clevis to attach to the carb? Well, apparantly when I hit the throttle kill switch at the end of my flight the rod pulled loose from the coupler that connected to the clevis that connected to the engine throttle lever. Therefore the throttle was left in the cut off position from the prior flight and I never knew it.

This was an Ulitmate Bi-Plane and you guys know that you can't see sh** inside the cowl when you do a decent job installing it. So the entire time I was trying to start the engine the carb was closed and when I moved the throttle I of course could hear the servo moving and assumed the throttle lever on the engine was moving but it was not. Sorry it took so long to get back with an update, christmas season is busy. Thank you for all your support!

42etus

My Feedback: (2)

That'll do it. Glad you found the problem and it was an easy fix.