YS 110 Idle Problem
08-31-2007, 09:37 PM
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YS 110 Idle Problem
Please Help! I can not make my YS 110 on 15% fuel, APC 17X4 idle below 3,900. I bought it used on a Mayhem, which had a Hyde softmont. It idled around 3k - fast but manageable. I moved the whole setup to a new PA Laser, same fuel and prop. It ran like it did on the Mayhem but I did not like the excessive wobbles at idle so I changed to a solid mount. The idle now is around 4,000 and the plane can not be taxied in after landing.
I burned 2.5 tanks of fuel and adjusted the valve and both needles to no avail. The HS appears to make the most significant change when tweaked. The LS is turned in all the way (richest setting). The valve screw is flush with the body. Valve screw 5 turns out or bottomed out made little difference.
With 1/2 tank left I decided to fly the Laser. The accelleration and top end are incredibly good. I made two perfect landings but could not taxi it back so I took off again and again. I flew until it ran out of fuel and deadsticked it in the grass. Bent the gear but no other damage.
I burned 2.5 tanks of fuel and adjusted the valve and both needles to no avail. The HS appears to make the most significant change when tweaked. The LS is turned in all the way (richest setting). The valve screw is flush with the body. Valve screw 5 turns out or bottomed out made little difference.
With 1/2 tank left I decided to fly the Laser. The accelleration and top end are incredibly good. I made two perfect landings but could not taxi it back so I took off again and again. I flew until it ran out of fuel and deadsticked it in the grass. Bent the gear but no other damage.
09-01-2007, 11:05 PM
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RE: YS 110 Idle Problem
My first gallon was YS 20/20 fuel. The idle was in the 3000 range - fast but manageable meaning run after the Mayhem and grab its tail. Others have said that 5%, 10% or 15% run fine in their YS's. Motorman37, do you really know for a fact that the YS 110 won't idle on 15%? It does not sound logical to me. Higher nitro will allow the engine to idle without dying. Mine does not go below 4000rpm.
I did some reading last night from someone who services YS. My understanding is that the regulator will turn off the pressurized fuel feed at low speed. The fuel feed beccomes suction like a regular engine. No fuel should come out if I disconnect the line at idle. As a matter of fact, mine squirts fuel out.
I started to take the regulator apart to take a look. The membrane appeared to have a permanent bow in the inward direction. Other than that it flexed fine when I turned the engine over. I did not find but very very little trash inside. I ran out of time as I was called in to work. I believe my regulator is not turning off as it should to switch the fuel feed from pressurized to suction.
I did some reading last night from someone who services YS. My understanding is that the regulator will turn off the pressurized fuel feed at low speed. The fuel feed beccomes suction like a regular engine. No fuel should come out if I disconnect the line at idle. As a matter of fact, mine squirts fuel out.
I started to take the regulator apart to take a look. The membrane appeared to have a permanent bow in the inward direction. Other than that it flexed fine when I turned the engine over. I did not find but very very little trash inside. I ran out of time as I was called in to work. I believe my regulator is not turning off as it should to switch the fuel feed from pressurized to suction.
09-02-2007, 04:57 AM
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RE: YS 110 Idle Problem
I have 2 - .63's and a 1.40 and have run them all quite successfully on 15% fuel but they do run and idle better on 20%. But it does sound like your diaphram is suspect. Anyone I took apart was flat.
09-02-2007, 05:24 PM
#6
RE: YS 110 Idle Problem
Coronabob,
Use this as an example. If you buy a car designed to run on premium, and instead run it on cheap 87 octane and experience problems with it running. What is the first thing the dealer is going to tell you.
Sure it sounds like you might have a regulater issue, and yes you can probaly get it to run, but it will never idle, transition or have run like it was intended to. Plus the needles are going to alot more sensitive, and you are probaly not running 20% oil either are you? That is what the YS is designed to run on.
It is kinda like buying a Ferrari and trying to run it on 87 octane.
FUEL RECOMMENDATION:
YS 20/20. This fuel is made by several different fuel manufacturers. All are suitable. 30% heli fuel also works well for those desiring more power.
GLOW PLUG:
YS #4 or OS Type F.
PROP SIZE RECOMMENDATIONS:
YS 63 -- 11 x 7, 11 x 8, 12 x 6, 12 x 7, 13 x 5, 14 x 4.
YS 91/110 -- 13 x 12, 14 x 10, 14 x 12, 15 x 8, 16 x 6.
YS 140 Sport - 15 x 13, 16 x 12, 17 x 8, 17 x 10.
YS 140DZ -- 16 x 14, 17 x 12, 18 x 8.
Other prop sizes may be used as long as the engines run in the recommended RPM ranges. In hot weather and break-in of new engines, use the smaller prop sizes to lessen the load on the engine to help it run cooler.
RECOMMENDED RPM RANGES:
YS 63 -- 10,500 to 11,500
YS 91/110 -- 8,800 to 9,800
YS 140 Sport -- 8,000 to 9,000
YS 140DZ -- 8,000 to 8,500
Use this as an example. If you buy a car designed to run on premium, and instead run it on cheap 87 octane and experience problems with it running. What is the first thing the dealer is going to tell you.
Sure it sounds like you might have a regulater issue, and yes you can probaly get it to run, but it will never idle, transition or have run like it was intended to. Plus the needles are going to alot more sensitive, and you are probaly not running 20% oil either are you? That is what the YS is designed to run on.
It is kinda like buying a Ferrari and trying to run it on 87 octane.
FUEL RECOMMENDATION:
YS 20/20. This fuel is made by several different fuel manufacturers. All are suitable. 30% heli fuel also works well for those desiring more power.
GLOW PLUG:
YS #4 or OS Type F.
PROP SIZE RECOMMENDATIONS:
YS 63 -- 11 x 7, 11 x 8, 12 x 6, 12 x 7, 13 x 5, 14 x 4.
YS 91/110 -- 13 x 12, 14 x 10, 14 x 12, 15 x 8, 16 x 6.
YS 140 Sport - 15 x 13, 16 x 12, 17 x 8, 17 x 10.
YS 140DZ -- 16 x 14, 17 x 12, 18 x 8.
Other prop sizes may be used as long as the engines run in the recommended RPM ranges. In hot weather and break-in of new engines, use the smaller prop sizes to lessen the load on the engine to help it run cooler.
RECOMMENDED RPM RANGES:
YS 63 -- 10,500 to 11,500
YS 91/110 -- 8,800 to 9,800
YS 140 Sport -- 8,000 to 9,000
YS 140DZ -- 8,000 to 8,500
09-02-2007, 10:15 PM
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RE: YS 110 Idle Problem
Gents,
Thank you for your help and inputs. I reassembled the regulator and test ran in my back yard. I found the problem. The end of my Z bend hit the post of the servo arm preventing it from closing the throttle.
I mounted my micro servo HS81 about 4" from the throttle arm and it is very difficult to watch the 'barrel' rotate on the YS110 carb with the air chamber in the way.
My YS now idles as it should and the barrel can be closed off to kill it. Now that I have it hard mounted, I found that the YS110 is a real thumper. It shakes quite a bit. I use a Xoar 16X6, which is balanced and no spinner. After I regapped the rocker arms, it stopped making the rattling sound and did not throw the prop.
I tightened the prop nut so hard that it crushed my Xoar prop. I need a larger, stainless steel washer. Maybe I should put my Hyde softmounts back on? Is the shake at idle normal with the YS110FZ? I am going to the LHS to buy YS 20/20 before I fly my Laser.
Thank you for your help and inputs. I reassembled the regulator and test ran in my back yard. I found the problem. The end of my Z bend hit the post of the servo arm preventing it from closing the throttle.
I mounted my micro servo HS81 about 4" from the throttle arm and it is very difficult to watch the 'barrel' rotate on the YS110 carb with the air chamber in the way.
My YS now idles as it should and the barrel can be closed off to kill it. Now that I have it hard mounted, I found that the YS110 is a real thumper. It shakes quite a bit. I use a Xoar 16X6, which is balanced and no spinner. After I regapped the rocker arms, it stopped making the rattling sound and did not throw the prop.
I tightened the prop nut so hard that it crushed my Xoar prop. I need a larger, stainless steel washer. Maybe I should put my Hyde softmounts back on? Is the shake at idle normal with the YS110FZ? I am going to the LHS to buy YS 20/20 before I fly my Laser.
