YS160 surging at Idle
 

I recently used my patern plane after it had sat around for a while.
The YS160 was running fine when i used it last. It's basically new.
The fuel system uses a header tank. There is a check valve fitted on the vent, and the filters are new (one on vent, one on delivery).
I run 30% coolpower blue

- At first i had alot of trouble starting the engine, and when it ran it was lean.
- It ran fine at about 2.75-3 turns out for one flights and then on the second the glow plug fell out, grrrr.
- After the plug was replaced it ran again like this for one more flight, and then went Rich!

- When i got home I found it wasn't sucking fuel very well. I flushed the filters, reg, and fuel lines, but did not disasseble the tank or engine
- I returned the neddle to two turns out
- The engine started easy and ran like this, but surged at idle.

- I pulled the tank out and found the clunk had corroded. I cleaned this and fitted new fuel lines.

- I tried running it again and it started fine.
- It was a little rich at two turns but the transition from low was good.
- After warming up i tried to get the engine to idle. It went low enough in RPM (low enough to stop), but was surging again
- At any other throtle position the engine was fine, it would just slightly surge around idle.
- I seem to need more throtle trim than last to stop it from stopping at low throtle.

- I pulled the regulator off and cleaned it. It seemed to be clean, and the ports were clear etc. I don't think there was a problem there?
- I have not adjust the reg, but up untill now the engine was good.
- I am yet to run it again, but i don't think i have found the problem just yet.

Any sugestions on why the idle is surging, but fine when the revs pick up?
Is something gumed up due to it sitting around?
Something dried up and is leaking?

I have posted on the YS page, but no luck so far.

RE: YS160 surging at Idle
 

Have you been adjusting the high end only, or the high and low ends?

RE: YS160 surging at Idle
 

same thing happened to me just before Nats, check the valve cover gasket and the head gasket. the valve cover gasket is what was wrong with mine. it just had a small crease in it. just enough to get some air, and that can cause the motor to surge at idle.

Is the motor running really hot?

hope this helps

Chris Odom
Team Black Magic
Team Dragon Fire
CAA

RE: YS160 surging at Idle
 

I had an engine than ran good before hanging it up for a while. When I pulled it out to fly again i had similar problem. I sent the engine back to ys. They replaced the carberator gaskets and now its fine.

RE: YS160 surging at Idle
 

If you are running 2.75 to 3 turns out on the high end then the pump is most likely too lean. The regulator on the pump should be flush with the housing or maybe a 1/2 turn in. If it is surging on idel the pump is too lean. Screw the reg. in to flush or the half in and then readjust the high end. You will most likely 1.75 to 2 turns out on the high end. Make sure all bolts are tight on the engine first before adjusting the carb. settings. I kind got this backwards on the trouble shooting, so check everything and even the fuel tubing on the engine. Then start adjusting the carb and pump settings.

I hope this helps a little.

Larry

RE: YS160 surging at Idle
 

Sometimes, the valve cover has a high spot causing the engine to surge during idling. Lightly wet sand it on 400 sand paper on a flat surface and try it again.

Adrian

RE: YS160 surging at Idle
 

The engine has been tuned in the past, and was working last time i used it.
I only adjusted the high end after having problems.
Originaly it was around 1.75 turns out, and i haven't checked the reg.
The transition from idel, and the idel was always good.

Only when i first ran it after sitting around did i need to adjust the high end to get it to run.
After the two flights t became rich and the high end was returned close to the original position.

I haven't tried re-tuning it because it was ok before i left it sitting around for a while.

RE: YS160 surging at Idle
 

Ok guys, i'll check the rocker cover, etc to see if anything is loose or leaking.

I've changed all of the fuel lines now, and flushed the reg.

I have the high set at about 1.75 (ran there last)

I'll try and see how that goes before touching the reg setting.

Thanks for your help

RE: YS160 surging at Idle
 

Tonye,
Remeber the reg. settings control the high end too. If you screw in on the reg. it will richen the low end and the high end so then you have to retune the high end to run properly. When you mention that the high end out more than 2 turns and you where surging at idel made me think the pump was too lean. But it sounds like at 1.75 out is pretty close. Usually it's something real easy to fix on these engines you just have to find it. I had a DZ 140 that ran great from idel to about 75% throttle and then all of sudden air bubble where coming out of the pump causing it to lean at highend. I rebuilt the pump and still same thing. It ended up being the pump housing was bad and I just replaced the whole pump and took the new parts out of the old one for spares. This engine now runs perfect and has loads of power. If you are sure about all the possible air leaks and all bolts are tight, just start over like it was new in the box with the reg. flush and 2 turns out on the high end and go from there. Seems like all my DZ 160's are about a half turn in on the reg. and 1.75 out on the high end.

Good luck
Larry

RE: YS160 surging at Idle
 

A problem I had on my new YS-170 that made mine hard to start and surge at idle was the "round black injector looking thing" that is pressed into the head. This has a spring loaded diaphram in it and acts as a check valve, if it sticks open like mine did, it allows fuel to freely escape and it will also suck air in return. Luckly,...the top of it unscrews and you can carefully re-seat the diaphram. Mine was pinched inside,...it's worth a look. It's run like a champ ever since,........:D You may find it's gummed up from sitting,..etc.

Bill H.
Team Fliton

RE: YS160 surging at Idle
 

It looks like your pumps is lean, is it smoking at idle and at 1/4 power?, or it just produces smoke form half to full power?

Regards

RE: YS160 surging at Idle
 

Thanks guys,

I haven't had a chance to check all of these things yet.
It does sound like the pump or reg may have been gummed up or had something in it.

The black injector cap is a little loose. I haven't looked at it in detail, but it moves side to side easily. (in/out is firm, no movement)

As mentioned i'll go round all the bolts and seals and try it again.

Is there an easy way to find a leak?
When you start to look at all the possibilities it becomes a little daunting :eek:

RE: YS160 surging at Idle
 

Side to side a tad,........That's normal as long as it dosen't pull in and out,...............I would check it to be on the safe side,.............I agree with the other guys!


Bill H.

RE: YS160 surging at Idle
 

The injector con move from side to side, it is normal, almost all engines do it, if the cap is loose, it does not matter either, as it is ventilated to let the air out of the injector line.

RE: YS160 surging at Idle
 

The rocker cover had a small burr near the bolt hole so i lapped it flat. It had some high patches which might not of helped.
Probably needs a new gasket. It did look to be slightly bunched up in one section.
I'll see how it goes.
The pump and springs look clean and working.
That's all the time i've had.

RE: YS160 surging at Idle
 

I had a similarish problem with my YS160. It started fine but would only run with the needle >3 turns open, the needle was also very insensitive. I stripped and regasketed everything - the only thing I found was a tiny pin-hole in the silicon pipe from the crankcase up to the regulator. Runs fine again now.

RE: YS160 surging at Idle
 

Have i mentioned how much these things suck when they don't work.

Now the pump is free flowing fuel from the tank.
If i pull the outlet tube off and take the clamp off the tank it free-flows fuel out the outlet tube.

When assembled if i turn the engine over it pump air bubbles back into the tank. The fuel just moves back and forward in the tube.
But if i stop the fue starts to flow from gravity.

The tubes are on the right fittings.

I'm guessing the pump valves are not seating or i've stuffed something up.
I've checked it twice now.

It wasn't doing this before i took it off...........[:@]

Oh well, might call a few people and see what i can find out.

RE: YS160 surging at Idle
 

The valves are check valves, both work in the same flow direction, I think you should be able to blow form the tank line but not back (obviously), unless something is backwards and I don't know if that can be done but looks like one is backwards, I will say you need a new pump, but before that, double check( I know again) and try blow from the hose with the pump disassembled so you can identify the ports and then visualize the way everything should be.

Make sure you reassemble to pump with new o rings and seals.

http://www.yspower.co.jp/pdf/DZ160-E.pdf It's easier to zoom in the pump than the actual manual.

This is a very good article on how everything works, don't know if read it before, but just in case.


http://www.gbrcaa.org/acrobatfiles/Y...%20Systems.pdf

RE: YS160 surging at Idle
 

Thanks,

I think i have fixed it......:eek:

I pulled it appart again. I noticed that the pump plate was coroded around the raised hole that the brass button on the diaphram sits against.
So i lapped the surface to clean it up.

I then cleaned everything again.

I assembled it this time with the machined surfaces horizontal, rather that sitting vertical in plane.

Afterwards the pump worked. So i primed it and set the reg slightly richer.

It ran and seemed to idle well.
I need to take it to the field and tune it now......hopefully i've seen the last of my problems.

RE: YS160 surging at Idle
 

Nice! good luck at the field