YS user seeking sympathetic ears :(
#102
I've got a 19x11 but never mounted it. I saw one go once and it looked like it was struggling, and I still had the original Oxai legs on and even 18" diameter was pushing it clearance wise.
With the Falcon legs and 30% nitro it can't hurt to bolt it up and see what it does?
With the Falcon legs and 30% nitro it can't hurt to bolt it up and see what it does?
Regards
#103
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Yes, even with the 18.5x12WPN cut back to 18 inches it does load the motor a bit, but I was getting about 7,250rpm on 20% nitro and it seemed to suit my flying. I first ran it with a 17x13 but the speed was all over the place, however it was nice to sport fly with. I tried a couple of props, even modded an 18x11WPN to 17.5x12.25 and it liked that.
With the original Oxai gear and grass field I was sort of stuck at 18 inches, but now I've got some longer legs on it I can start experimenting again. With two votes in for the 19x11 sitting in my cupboard, there's no harm in trying it..
Flywilly, the Hanno is sitting in an Slingshot which is an Aussie design. The kit quality was a bit iffy and I'd dearly love to build one from scratch "properly". It'd make a fantastic electric design as well.
With the original Oxai gear and grass field I was sort of stuck at 18 inches, but now I've got some longer legs on it I can start experimenting again. With two votes in for the 19x11 sitting in my cupboard, there's no harm in trying it..
Flywilly, the Hanno is sitting in an Slingshot which is an Aussie design. The kit quality was a bit iffy and I'd dearly love to build one from scratch "properly". It'd make a fantastic electric design as well.
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#106
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Just a quick update on the 19x11.
Much noisier on the ground than my usual prop (18.5x12wpn cut back to 18"), however in the air it doesn't sound much different from my usual prop. The plane seems to be a bit more consistent in the yaw axis now, where with the other prop it did tend to wander left or right dependent on the power setting and attitude.
The wind is 30km/hr gusting to 40km/hr today it's hard to tell much, but it isn't struggling for speed pushing over into the wind.
So far the prop is definitely worth keeping on for a few more flights to give it a chance.
I checked my plug gap the other night, and I have it set to about 0.38mm (0.015" ).
Much noisier on the ground than my usual prop (18.5x12wpn cut back to 18"), however in the air it doesn't sound much different from my usual prop. The plane seems to be a bit more consistent in the yaw axis now, where with the other prop it did tend to wander left or right dependent on the power setting and attitude.
The wind is 30km/hr gusting to 40km/hr today it's hard to tell much, but it isn't struggling for speed pushing over into the wind.
So far the prop is definitely worth keeping on for a few more flights to give it a chance.
I checked my plug gap the other night, and I have it set to about 0.38mm (0.015" ).
#108
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10 thou would make life easy for the cdi unit..
Something I've realised in the last few weeks is that my valve clearances have been bordering on too tight for the 7 years I've been running it. Just prior to swapping to the 19x11, I cleaned the plane up, reduced the valve clearance a bit then put it away. The very next flight at the field (same prop, same fuel) it started a very small misfire about 4 minutes in that got worse but was still flyable. I reached for the screw driver to lean the regulator, but stopped, remembered what I'd changed from last flight then opened up the clearance again and it was back running without fault again.
For whatever reason, my engine is not happy with less than 0.05mm (0.002") valve clearance at TDC. The clearance on the exhaust side is all over the place and even with 0.05mm at TDC it gets tight at other points. I wonder if the cam grind is/was a bit iffy?
I'd read on the 'net about people running 20% oil without problems, something my engine has never run happily on. I'd seen the videos where on takeoff and different times you could see the individual puffs of smoke in the exhaust trail and wondered how they could run so rich because my engine could never be set like that and run properly. Even for the couple of years when it was "reliable" I had to have it set super lean (needle and regulator) to prevent misfiring, so lean that the high speed needle was often on the lean side of peak rpm. Being my first YS and no other YS's (cdi or otherwise) around my area I figured that's just how it was.
What a difference this engine is to run now.
Something I've realised in the last few weeks is that my valve clearances have been bordering on too tight for the 7 years I've been running it. Just prior to swapping to the 19x11, I cleaned the plane up, reduced the valve clearance a bit then put it away. The very next flight at the field (same prop, same fuel) it started a very small misfire about 4 minutes in that got worse but was still flyable. I reached for the screw driver to lean the regulator, but stopped, remembered what I'd changed from last flight then opened up the clearance again and it was back running without fault again.
For whatever reason, my engine is not happy with less than 0.05mm (0.002") valve clearance at TDC. The clearance on the exhaust side is all over the place and even with 0.05mm at TDC it gets tight at other points. I wonder if the cam grind is/was a bit iffy?
I'd read on the 'net about people running 20% oil without problems, something my engine has never run happily on. I'd seen the videos where on takeoff and different times you could see the individual puffs of smoke in the exhaust trail and wondered how they could run so rich because my engine could never be set like that and run properly. Even for the couple of years when it was "reliable" I had to have it set super lean (needle and regulator) to prevent misfiring, so lean that the high speed needle was often on the lean side of peak rpm. Being my first YS and no other YS's (cdi or otherwise) around my area I figured that's just how it was.
What a difference this engine is to run now.
Last edited by bjr_93tz; 04-10-2017 at 04:06 PM.
#109
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10 thou would make life easy for the cdi unit..
Something I've realised in the last few weeks is that my valve clearances have been bordering on too tight for the 7 years I've been running it. Just prior to swapping to the 19x11, I cleaned the plane up, reduced the valve clearance a bit then put it away. The very next flight at the field (same prop, same fuel) it started a very small misfire about 4 minutes in that got worse but was still flyable. I reached for the screw driver to lean the regulator, but stopped, remembered what I'd changed from last flight then opened up the clearance again and it was back running without fault again.
For whatever reason, my engine is not happy with less than 0.05mm (0.002") valve clearance at TDC. The clearance on the exhaust side is all over the place and even with 0.05mm at TDC it gets tight at other points. I wonder if the cam grind is/was a bit iffy?
I'd read on the 'net about people running 20% oil without problems, something my engine has never run happily on. I'd seen the videos where on takeoff and different times you could see the individual puffs of smoke in the exhaust trail and wondered how they could run so rich because my engine could never be set like that and run properly. Even for the couple of years when it was "reliable" I had to have it set super lean (needle and regulator) to prevent misfiring, so lean that the high speed needle was often on the lean side of peak rpm. Being my first YS and no other YS's (cdi or otherwise) around my area I figured that's just how it was.
What a difference this engine is to run now.
Something I've realised in the last few weeks is that my valve clearances have been bordering on too tight for the 7 years I've been running it. Just prior to swapping to the 19x11, I cleaned the plane up, reduced the valve clearance a bit then put it away. The very next flight at the field (same prop, same fuel) it started a very small misfire about 4 minutes in that got worse but was still flyable. I reached for the screw driver to lean the regulator, but stopped, remembered what I'd changed from last flight then opened up the clearance again and it was back running without fault again.
For whatever reason, my engine is not happy with less than 0.05mm (0.002") valve clearance at TDC. The clearance on the exhaust side is all over the place and even with 0.05mm at TDC it gets tight at other points. I wonder if the cam grind is/was a bit iffy?
I'd read on the 'net about people running 20% oil without problems, something my engine has never run happily on. I'd seen the videos where on takeoff and different times you could see the individual puffs of smoke in the exhaust trail and wondered how they could run so rich because my engine could never be set like that and run properly. Even for the couple of years when it was "reliable" I had to have it set super lean (needle and regulator) to prevent misfiring, so lean that the high speed needle was often on the lean side of peak rpm. Being my first YS and no other YS's (cdi or otherwise) around my area I figured that's just how it was.
What a difference this engine is to run now.
Sounds like you're starting to get a handle on it Brett. The cdi's are a different beast to run and tune. YS have changed the clearance settings over the years. Used to be a minimum of 2 thou, now for the 185 they say zero to 4 thou. I use a 1 1/2 thou feeler guage and set it so there is a slight amount of resistance as it slides through. I think setting to zero is asking for trouble.
I've seen different percentages of oil run up to 20% with no issues. I've run various brews from 9 -15 with mixture settings being the only change required. Now you have it running well, I think you will be to use less oil OK. Because it was so lean, I reckon it needed the extra oil to keep it cool enough. It does sound like over heating was the cause of the poor running, but there were other problems that was causing the over heating. If that makes sense.
Fly the pants off it now
#110
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That's the plan now Scott.
That valve clearance issue has been a bogey man hiding in the background for a long time now, which for the most part has been masked by oil content, needle and regulator settings. There's still something not right with my engine that requires I run it at the looser side of specifications, but I'm going to leave sleeping dogs lie for a while and might replace the cam at the next overhaul as it's about the only bit that's still original apart from the crank.
I'll probably drop back to 10% MV oil soon, but I'll put up a few more flights with the 19x11 before I change anything. It's still bedding in a new ring and I don't want too many things changing at the same time.
That valve clearance issue has been a bogey man hiding in the background for a long time now, which for the most part has been masked by oil content, needle and regulator settings. There's still something not right with my engine that requires I run it at the looser side of specifications, but I'm going to leave sleeping dogs lie for a while and might replace the cam at the next overhaul as it's about the only bit that's still original apart from the crank.
I'll probably drop back to 10% MV oil soon, but I'll put up a few more flights with the 19x11 before I change anything. It's still bedding in a new ring and I don't want too many things changing at the same time.
#111
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That's the plan now Scott.
That valve clearance issue has been a bogey man hiding in the background for a long time now, which for the most part has been masked by oil content, needle and regulator settings. There's still something not right with my engine that requires I run it at the looser side of specifications, but I'm going to leave sleeping dogs lie for a while and might replace the cam at the next overhaul as it's about the only bit that's still original apart from the crank.
I'll probably drop back to 10% MV oil soon, but I'll put up a few more flights with the 19x11 before I change anything. It's still bedding in a new ring and I don't want too many things changing at the same time.
That valve clearance issue has been a bogey man hiding in the background for a long time now, which for the most part has been masked by oil content, needle and regulator settings. There's still something not right with my engine that requires I run it at the looser side of specifications, but I'm going to leave sleeping dogs lie for a while and might replace the cam at the next overhaul as it's about the only bit that's still original apart from the crank.
I'll probably drop back to 10% MV oil soon, but I'll put up a few more flights with the 19x11 before I change anything. It's still bedding in a new ring and I don't want too many things changing at the same time.
Frazer Briggs was running the 19 x 11 on his 170 at the Trans Tasman in NZed last weekend and if flew the plane really well.
#112
If you plan on replacing the camshaft at some point, IMO, it would be prudent to also replace the lifters. But maybe that was already in your plan.
I'm glad you are getting a handle on the running issues. I know how frustrating they can be.
Ken
I'm glad you are getting a handle on the running issues. I know how frustrating they can be.
Ken
#113
I fly with 23% oil and 30% nitro, have ran it on all my YS engines, Glow or CDI, my engines run reaally smooth with it.
On the valves, that is why I suggested to check with the engine warm, valves tend to open when hot at a really close gap.
Regards
On the valves, that is why I suggested to check with the engine warm, valves tend to open when hot at a really close gap.
Regards
#114
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Being a bit lousy with my money, I mixed up batch of 25% nitro and 10% coolpower MV oil and I must say I was very surprised at the drop in performance. On the 19x11 I dropped from about 7.5K rpm to about 7.2K rpm, I was hitting full power much more often and the plane looked a little tired compared to how it had been running.
I only ran 3 tanks so the mixture could probably be tweaked a bit more, but it also seemed to be a bit thirstier as the tank had less left in it when the timer went off compared to the 30%15% brew. I'm at about 1500ft ASL
I'm happy to experiment a little now, as I'm enjoying the stick time although I don't remember this engine sucking down the fuel like this before. The 600cc tank is nearly disappearing in the same time as the 360cc tank I used to have fitted.
I only ran 3 tanks so the mixture could probably be tweaked a bit more, but it also seemed to be a bit thirstier as the tank had less left in it when the timer went off compared to the 30%15% brew. I'm at about 1500ft ASL
I'm happy to experiment a little now, as I'm enjoying the stick time although I don't remember this engine sucking down the fuel like this before. The 600cc tank is nearly disappearing in the same time as the 360cc tank I used to have fitted.
#115
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Being a bit lousy with my money, I mixed up batch of 25% nitro and 10% coolpower MV oil and I must say I was very surprised at the drop in performance. On the 19x11 I dropped from about 7.5K rpm to about 7.2K rpm, I was hitting full power much more often and the plane looked a little tired compared to how it had been running.
I only ran 3 tanks so the mixture could probably be tweaked a bit more, but it also seemed to be a bit thirstier as the tank had less left in it when the timer went off compared to the 30%15% brew. I'm at about 1500ft ASL
I'm happy to experiment a little now, as I'm enjoying the stick time although I don't remember this engine sucking down the fuel like this before. The 600cc tank is nearly disappearing in the same time as the 360cc tank I used to have fitted.
I only ran 3 tanks so the mixture could probably be tweaked a bit more, but it also seemed to be a bit thirstier as the tank had less left in it when the timer went off compared to the 30%15% brew. I'm at about 1500ft ASL
I'm happy to experiment a little now, as I'm enjoying the stick time although I don't remember this engine sucking down the fuel like this before. The 600cc tank is nearly disappearing in the same time as the 360cc tank I used to have fitted.
Dropping from 30 to 25 nitro would require the mixture to be leaned and going from 15 to 10 oil, would also require the mixture to be leaned out. Both on the reg and main needle. The reg makes a huge difference to fuel consumption if it's too rich. Much more so than the main needle.
I wouldn't be dropping nitro percentage at 1500ft.
My 185cdi swings a 21 x 10 at 6900 and uses 250cc's per flight.
#116
The extra fuel consumption is to be expected on less powerful fuel, as you will fly the engine at a higher power setting automatically as you are used to the aircraft speed, so if the engine is lacking power you will use more fuel to try to achieve what the more powerful fuel can do with less volume.
I can fly two sequences on 600cc and land with a little less of one third tank, running 30%nitro and 23% oil.
Regards
I can fly two sequences on 600cc and land with a little less of one third tank, running 30%nitro and 23% oil.
Regards
#117
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Yes Scott, I had to lean the reg about 1/8th turn and can't remember what I did with the needle as I just tweaked it with the tacho until it was just shy of peak rpm. It'll take a few more tanks to dial it in.
Apereria, you're right about having to flog it harder to get the same performance. It's the little things you notice like pushing/pulling into the wind at the top of an upline, with the extra grunt you could wait until you were halfway over before feeding in some extra power to accelerate a bit to keep that constant ground speed look, now I'm needing to use the last part of the upline to pick up a bit of extra speed before pushing over.
To be fair, I'm also used to flying the plane with the 360cc tank, the 600cc tank when full is very noticeable. Even with the 360cc tank, I never flew it full for a competition round, only for practice.
Apereria, you're right about having to flog it harder to get the same performance. It's the little things you notice like pushing/pulling into the wind at the top of an upline, with the extra grunt you could wait until you were halfway over before feeding in some extra power to accelerate a bit to keep that constant ground speed look, now I'm needing to use the last part of the upline to pick up a bit of extra speed before pushing over.
To be fair, I'm also used to flying the plane with the 360cc tank, the 600cc tank when full is very noticeable. Even with the 360cc tank, I never flew it full for a competition round, only for practice.
#120
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On a serious note, towards the end I was worried it was something I was doing wrong, and to some extent one of the issues was something I was doing but it wasn't necessarily wrong according to the manual. If I had purchased a brand new engine I would have run it for x hours, then tightened the valve clearance and may (or may not) have been back to square one with the same problem with a brand new engine.
I know that's what I did with this engine from new and mostly I've been able to tune around it not knowing any better. I had a fantastic run with it for a couple of years with the clearance being on the verge of too tight, but at a rebuild I set it a fraction too tight (but within spec) and the woes began shortly after. Every time I pulled the engine to swap parts it went back together with about 1 thou of valve clearance and I was having problems.
The penny finally dropped when I replaced the head assembly and left the clearances loose for two flights to bed it in and and it ran fine. The valves in the original head were leaking so the new head assembly "fixed" the problem or so I had thought, except the problem came back during the next trip to the field after I had re-set the clearances to 1 thou.
Now I've got the engine sorted I've bought myself a kite to play with. https://prismkites.com/product/hypnotist/
#124
Ha, if you go back to the first post I opened it up with.
I was already a year in and nearly everything replaced before I started this thread.
On a serious note, towards the end I was worried it was something I was doing wrong, and to some extent one of the issues was something I was doing but it wasn't necessarily wrong according to the manual. If I had purchased a brand new engine I would have run it for x hours, then tightened the valve clearance and may (or may not) have been back to square one with the same problem with a brand new engine.
I know that's what I did with this engine from new and mostly I've been able to tune around it not knowing any better. I had a fantastic run with it for a couple of years with the clearance being on the verge of too tight, but at a rebuild I set it a fraction too tight (but within spec) and the woes began shortly after. Every time I pulled the engine to swap parts it went back together with about 1 thou of valve clearance and I was having problems.
The penny finally dropped when I replaced the head assembly and left the clearances loose for two flights to bed it in and and it ran fine. The valves in the original head were leaking so the new head assembly "fixed" the problem or so I had thought, except the problem came back during the next trip to the field after I had re-set the clearances to 1 thou.
Now I've got the engine sorted I've bought myself a kite to play with. https://prismkites.com/product/hypnotist/
I was already a year in and nearly everything replaced before I started this thread.
On a serious note, towards the end I was worried it was something I was doing wrong, and to some extent one of the issues was something I was doing but it wasn't necessarily wrong according to the manual. If I had purchased a brand new engine I would have run it for x hours, then tightened the valve clearance and may (or may not) have been back to square one with the same problem with a brand new engine.
I know that's what I did with this engine from new and mostly I've been able to tune around it not knowing any better. I had a fantastic run with it for a couple of years with the clearance being on the verge of too tight, but at a rebuild I set it a fraction too tight (but within spec) and the woes began shortly after. Every time I pulled the engine to swap parts it went back together with about 1 thou of valve clearance and I was having problems.
The penny finally dropped when I replaced the head assembly and left the clearances loose for two flights to bed it in and and it ran fine. The valves in the original head were leaking so the new head assembly "fixed" the problem or so I had thought, except the problem came back during the next trip to the field after I had re-set the clearances to 1 thou.
Now I've got the engine sorted I've bought myself a kite to play with. https://prismkites.com/product/hypnotist/