Saillfish

My Feedback: (17)

I have a new YS 140 sport that wont idle. I have 2 ys 63's and 2 110's so I know a little bit about tuning these engines. I have read all the post on this engine and tried everything. I even drilled out the throttle barrel to 1/8th inch. I bet that voids my warr. if I send it in. My problem is it wont idle. It comes down to about 2200 or 2500 rpms and runs about 10 to 15 sec and just dies like you hit a kill switch. It seems to have a lot of air in the line from the reg. to the carb. It has no air bubbles going into the reg. It even seems like the fuel flows backwards a bit. I have chased the needles till I am blue in the face. I have set them back to factory over and over. I have messed with the reg both ways and tried differant fuel, 2 new plugs. One ys and one OS. I even isolated a new tank away from the plane with no filters or fillers. Any advise or help before I need knee replacement from knealling for hours tuneing. Thanks!

dmccormick001

Are you using a fuel with 20% nitro? On a new one you'll just about have to. Once you get it broken in well you can back off the nitro some with no problems, but initially you need to run at least 20% nitro.

The only other thing I can suggest is to get it as close as you can and then make very, very small adjustments, giving the engine time to respond after each one. These things are very sensitive, and slow to respond to changes. But you may already know that. Just be patient. I had to adjust mine to idle at around 3000 at first, ran it for a while at that setting, and then as it began to break in I was able to ease the idle speed on down to around 2000. Now it chugs along and sometimes makes me think it might quit, but it never has. Hang in there and yours may "come to you".

David

petec

My Feedback: (58)

I have to agree with David, if it is new you will have to run the idle at a higher RPM until it breaks in. Also the higher nitro fuel will idle lower than a lower nitro content fuel.

My YS engines don't usually settle down to a low idle until they have ingested a gallon or two of fuel.

Saillfish

My Feedback: (17)

I am running 30 percent nitro fuel. Cool power heli. Also have put ys 2020 powermaster in it. Have not had this problem with any of my other YS engines. I have run a half gallon thur it as of now. Cant fly it until it idles better cuz I would never get it down at 3000 or so rpm's. The airplane only weighs 10lbs swinging a 17x10 apc it would still be flying pretty fast. At 3000 holding it on the ground it seem like it could almost take off.

Cyberwolf

My Feedback: (4)

Sailfish as a rule I will grab a used plug to do my initail run in of a new engine keep the RPM's up and let it run a few tanks thru it NOT WOT but from say 4-7K and I allow it to cool off between runs ,after about 2-3 12 OZ tanks I then install the new plug and go for the tune. A new engine as it breaks in will emit micro particles that will get attached to the glow plug and contaminate it causeing the some idle issues and even some top end issues at times
Another thing how old is your fuel? I have had fuel that would run fine in one engine and wouldn't in another of the same brand.