rc-plane

I am having trouble with my new ys-110. I am trying to break it in and everytime I start the engine the idle is way low and I had to adjust the trim almost all the up to make it idle. Once I got it to idle I brought the throttle up to just below 1/2 and let it run for a minute to let it warm up, once I had the engine warm I thought I would move the throttle up a little. One click past 1/2 way and the fuel sucked back into the fuel tank and started to die. I was able to adjust the throttle down in time to let the fuel catch up with the engine and it continued to run. Everytime I tried to increased the throttle, weither it was a slow increase or a fast one, the fuel would suck back into the fuel tank. After about 3 minutes the engine died and I decided to let it cool off so I could check it over for leaks in the fuel system. I found no leaks, but when I moved the prop I could hear a swishing sound like something was leaking, but I could not find anything. Can someone please help!

Troy Newman

the big question is the tank holding pressure. Is you check valve installed properly. If the tank is under pressure its usually 6-8psi there is no way the fuel can suck back to the tank.

A YS engine that is pressurized never sucks fuel from the tank. Instead the tank is pressurized and the fuel is pushed by the pressure to the engine. The only time fuel is not being force fed to the engine is when the engine is running at or below 2000rpm.

what you are saying sounds like there is not check valve in the pressure line or the check valve is installed backward.


Troy Newman
Team YS

rc-plane

We had the lines reversed on to the engine. I changed them and it ran good for about 8 minutes. Then for no reason it died. the throttle was at 1/2 and it seemd to be runnig good. I was able to run the throttle all the way up and down with cood transition through out the power band. It did seem to not change much in engine noise between 3 clicks above 1/2 to full throttle. I did adjust the high end but not the low end setting, or the regulator. It started raining so I put everything up for the moment. Any pointers on why it died or why there was not much difference between a little over half and full throttle? Thanks for any help!

Troy Newman

I never run them more than about 4 mins on the ground. They can get way too hot.

If the lines were reversed then you running it out of fuel as the pressure would start to build up. Basically the pressure could not build in the tank as the pressure was back flowing through the pressure line and the supply side was not getting any fuel. Lack of fuel is a lean run. You could have toasted the glow plug.

It could die for various reasons. If you were at half power it could have been too lean on the regulator and cooked the plug. Or it could have been too rich on the regulator and loaded up. I just can't tell you.

Its kinda like taking your car to the shop and telling the guy when I turn the key over it doesn't start. He first question is does the battery have power? did you put gas in it? Is the starter cranking the engine over? Are the spark Plug wires connected? Lots of options.

Run the engine based on the guidelines in the website below and you will have an idea how to set the mixture. If could be that you damaged the glow trying to run it with the lines reversed. This was running it lean!

http://www.probuild-uk.co.uk/factsheets/ys_engines.php

Also in your 8mins of run time was the tank empty when you got done? If you only have a 10oz tank then it could be gone running 8mins at higher power settings. I would say 16oz tank should give a good 10min flight maybe as much as 12mins depending on you are running it.

Troy Newman
Team YS

rc-plane

No the tank was not empty.

rc-plane

Tony, I took the Yak out today and flew it with the ys-110. It did great, I had an older friend that flys ys engines alot help me adjust it before flying. The only problem was that as I was setting up for my final approach for landing it died and I had to dead stick it in. We let her cool down then tried to adjust the low speed needle thinking that after it warm up it was leaning out the engine. I took it up again and flew for about 10 minutes, set up for the final and it died once again, another dead stick on a new plane starts to get you a little nervous. We adjusted the low end once again as soon as we had her on the ground and I flew her again. No problems with the engine in the air, doing tricks, slowing down and then picking back up on speed. But for the third time she went dead stick as I was bringing her in for landing. Any ideals on what could cause this? I also lost my muffler and extension pipe on the last flight, So i put her down ASAP, I have read some other post where you talk about that it is ok to run without a muffler but not without an extension, would it be better to buy an header pipe or just go back with an extension pipe or extension pipe and muffler? Thanks again for all your help!
rc-plane

rc-plane

?

Troy Newman

When the muffler fell off the engine likely went really rich this could account for the quiting on the last run. It takes several tanks and even maybe a gallon or two before the engine gets broken ina nd idles reliably. In that time likely a new glow plug will help too. When the engine is breaking in small bits of metal are flying around inside. These can hit the coil on the plug and burn a hot spot on it. This will cause the plug to become less effective...and idle performance will suffer.

Like I said before use the instructions on this page below to get the mixture set properly.

http://www.probuild-uk.co.uk/factsheets/ys_engines.php

If you use these instructions on how to set the idle it will be set correctly. It may take a couple of gallons before the engine starts to really break in and idle reliably all the time.

Troy Newman
Team YS

Zeeb

My Feedback: (41)

Just one more quick thought on your engine idle slowing down after flying it for a bit since I've been flying my Funtana again lately and it happened to me as the ambient temperatures got hot when it went from morning to mid-day. IF your high speed needle is too lean the engine will get hot and the idle speed will decrease. It can be just a tiny bit lean and they'll do this, and by tiny I mean in the area of 1/16th to 1/8th of a turn on that needle. Make sure you're not lean on the top end. I should have noticed it was starting to sag on the uplines, but I attributed it to the density altitude going up due to the increasing air temperature...

I know this sounds counter-intuitive needing to go richer as the air temperatures are going up, only thing I can think of is the extra fuel is necessary for cooling as the air temps get hot i.e. the 90 to 100 degrees F area and it worked for me yesterday.

edit info;

This is of course with the muffler still on and does not apply to the flight where you lost your muffler.

rc-plane

thanks