lilhachet

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Thank you VERY much., Guy

MRMcFarlandM

Hi Guys,
Has anyone done comparison between the 1.40 sport and the 1.40L are they about the same power wise.

Thanks Mike,

Cyberwolf

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The 140 L has more power but its a little on the tempermental side to get it adjusted.

rc-plane

I have a problem with my new ys-110. When I start the engine the idle is to low, as I adjust it the engine seems to run OK, then as I try to run it a half throttle it wants to die and I can see the fuel returning to the tank like it is being sucked back in. If i go ahead and give it full or 3/4 throttle it will die. I am just trying to break the motor in at this point, but I wanted to get the high speed and low speed adjustments made to the engine. Can anyone tell me why the fuel is being sucked back into the fule tank? Thanks,

isaacslaw

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Perhaps your fuel lines are reversed. As you look at the engine from the top down with the prop shaft pointing away from you, the brass nipple on the left is the pressure line and the one on the right is the intake line. Check valve goes with the arrow pointing to the tank on the left hand line.

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!

lilhachet

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Tried runnin the motor today. It just dosen't like to stay at high RPM's without quitin.I throddle back and it's ok untill I hit the throddle again. and it will run about 30 secs and quit again. I tried turnin the HS needle out to richin it up but then when I go to full it wants to be leaned out more? then quit runnin? When I first got the motor I ran my reg. 15% nitro in it, maybe a tank, tops. I didn't know I had to have a diff. fuel for this motor,So I bough a gallon of ys/saito 20% fuel today.
' Do you think the reg. needs a rebuild? Thanks, Guy

kochj

when comparing the YS 1.40 sport to a 1.80 Saito (I am sure this has been asked before) Anyone had both?
Same power wise?

Justin

isaacslaw

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RC Plane and Lilhatchet:

These engines tune differently from other engines and it can take awhile to get used to them. You need to have a somewhat methodical approach to tuning them. It can be very frustrating if you try to tune them without knowing the engine. Also, others have been frustrated when letting "engine experts" at the field tune them who do not know about YS specifically. Here is a link that has been posted previously in this thread which you can safely call the YS bible. It helped me tremendously. Once tuned, no other engine I have seen even comes close to the power, throttle response and reliability of the YS's. Good luck!

[link=http://tech.flygsw.org/ys110.htm]YS Bible -- from the Greater Southwest Aeromodling Club[/link]

lilhachet

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Thank you, a link that really works. I'll go over my motor with this new info and let you know how I made out.

lilhachet

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Hi, also, when I do get it to run for a min or two, there is a small air leak, if you are looking at the throttle side, it's leaking aroung the throttle barrel. Is this serious? Thanks, Guy PS, it just bubbles a little

AcroJo

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bad gasket, bad seat or something is loose. its worth investigating

Cyberwolf

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Any air or fuel leak is serious on a YS engine, sounds like the o ring or throttle barrel seal is leaking and needs replaced.

lilhachet

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WOW! it started right up? After warm up,I let it idle for about a min or two then hit the throttle and it took about twenty seconds or so to clear the carb.What would need ajustment at this point to clear this up? Thank you so much. Guy

Cyberwolf

My Feedback: (4)

You did adjust the HSN after you got it to run correct and thats when this was happening.
I kid you not some of my YS engine's flood bad with the needle out 2 turns, they run at maybe 3/4 of a turn out.
If that was the case I would think you have something a miss with the regulator,maybe a piece of dirt or a bad plunger spring or both.
They can at times be a real challenge but hang in there. sounds like your closer.

lilhachet

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And where would I get parts for this motor? Also this is an AC 91. The site you sent me to is for a FZ.Is there a big diff? Thanks again. Guy

AcroJo

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the 110 is a modified 91. most parts ordered are from the 91 central hobbies carries parts as does ys performance

lilhachet

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the ys preformance site, I can't seem to get there.

rlipsett

if the engine loads up from a low idle then the low sped adjustment on the throttle body needs to be opened a little, it acts like an air bleed screw. If the engine loads up when it is running faster then idle then you have to adjust the pressure regulator. Turn it in if the engine was loading up and out if it is starving. make sure the glow plug is good and prepare to be amazed.

isaacslaw

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Hi fellas:

Question about the valve clearances on a YS 110:

Yamada says .1 mm clearance on both intake and exhaust valves. Greater Southwest Aeromodellers [link=http://tech.flygsw.org/]Greater SW YS Page[/link] YS pages for the rebuild of the YS 91 says valve clearnace should be .002" for intake and .004" for exhaust. The guy only says that he found that they run "better" with the different clearances--does anyone know from messing around with different clearances what the exact effect is or what is better? (EG: higher rpms? easier tuning? etc)

I ask because I am only spinning an apc 16X6 at 8900 rpms after a rebuild. The engine is now pretty difficult to tune as compared to before I adjusted my valves and did the rebuild (quitting on idle and landing approaches, idle just not stable). I am suspicious of my fuel and am going to try a fresh gallon of it, but also am thinking that it may be the valves which are at .002" and .004"

MikeEast

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www.yspartsandservice.com

Richard Verano has assumed command at that site. The old YS performance site is not useful as far as I know anymore.

AcroJo

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I always set equall and my gauge is simply a piece of printing paper. As you know, the gap increases as the engine heats up. I do know for performance ( in racing) often the exhaust setting is slightly wider. I think for something this small, your tollerances must be exact. If your exhaust clearance is too great it will be opening prematurely and result in lost power. Joe

Cyberwolf

My Feedback: (4)

In most engines the valve lash is more on the exhaust than the intake due to more heat, weather it be car truck or model engine. Myself I have never seen a .002 tighter on the intake side make any difference in a YS engine, as long as the correct clearance is established my engines run great, So I have always used the supplied feeler gage for both.

You need to look at a few things here
1. Did you clean and lap the valves back in when the engine was rebuilt.
2. How much wear was in the cyl.
3. Did you use some fine paper or emery cloth to put a cross hatch back in the cyl for proper breakin of the new ring.
4. If the valves was lapped how much valve stem clearance was there? To much wear here can ruin the whole rebuild due to the fact no matter what,
the valve will always leak not holding the proper compression.
5. How does the compression feel now after the rebuild?
6. Are you positive that you have the cam timing correct one tooth off makes a big difference.
7. Did you do a breakin on the engine again like when it was NIB.

I have noticed this, putting a new ring on a worn cyl even one that looks and measures great takes longer to break in and make a good seal, Which in itself could cause every symtom your having.
Also the reg and needles could have the same effect if not adjusted properly. Any air or fuel leaks in the fuel system can create propblems .In fact a leaky valve cover can cause more grief than you can imagine and is hard to find. Last the glow plug could be the culprit if the mixture was way rich during the breakin period.
A easy check if all the coils still lights up is to Ohm it compared to a new one.


8900 on a 16x6 useing what fuel. Also what did the engine turn that prop when new, with what fuel.
Guys here are running a 16x6 APC but also useing 30% fuel to do so. And I have not noticed any real high RPM's 9 K is about the norm from what I have seen.

Just a few things to check ,but only do one at a time I would start with the easy ones first. If your fuel doesn't prove out to be the problem
Good Luck

isaacslaw

My Feedback: (4)

Thanks AcroJo and Cyberwolf!

When rebuilding the 110, I did not swap out the sleeve. The old one still had cross-hatching visible and didn't seem scored or damaged. The piston also seemed alright with only some discoloration on the top. The ring also seemed alright, but I changed it since I had one and had it apart.

When I first got it, it supposedly had only a gallon or two of fuel through it. I have run about 7-10 gallons of 30% coolpower heli or 30% wildcat heli. When I first ran the engine up last year, it was turning APC 16X6 at 10,000 + rpms. I remember one run where I had to turn it down a bit because it was approaching 10,400 which I believe is much too high for this engine. After a couple of gallons, it settled down to 9600-10,000 depending on the day.

I got a really good deal on some 30% coolpower heli fuel here last year. The 30% over here in Cyprus costs anywhere from $35-$55.00 or so and I bought about 7 gallons for $22.00 each. The fuel has been kept in the original container and I suspect that over the past year it has absorbed more and more moisture as the fuel level has decreased. That's my theory anyway and I won't hurt to change out for some fresh fuel.

I did lap the valves and tested them by pouring in some methyl alcohol upside down and it was still holding at the same level after about 8-10 minutes so I figured it was good.

When I first ran up the engine after the rebuild, I had a really bad airleak that I could hear coming from the airchamber box. I reattached it and the leak went away. Now that I think about it, though, I notice that after some runs there is very little if any pressure left in the tank. Other runs provide the hiss and small spray of fuel when I release the vent line. I will check everything over again. Does anyone know a good way to pressure test a YS? I would usually think of putting a soapy solution of water over everything and look for bubbles, but seems like that would be hard with the propeller going 9,000 rpms.

The last thing on my mind now is that the engine distinctly lacks compression compared to when I first got it. My standard starter has no trouble whatsoever spining the prop around-- no need for a running start like it took before. I had attributed this to the ring not being broken in yet. I have about 5 14oz tanks through it now and I don't see much difference. I know it usually takes at least a gallon or two before its really set, but I was expecting to see the idle start to smooth out by now.

I'm going to try these suggestions from you guys one by one until I run out of suggestions or find the problem--starting leaks, then with the fuel and then the valve clearances. Thanks again for the help fellas!

Tim Isaacs

AcroJo

My Feedback: (1)

i think that you will reach just as much compression/pressure when turning it over by hand, or with an electric starter with the prop off, for a soap test. its worth a try. good luck, joe