Yamada YS 63
03-07-2003, 12:34 PM
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Yamada YS 63
YAMADA YS 63
Bore: 26.16 mm
Stroke: 19 mm
Displacement: .623 cubic inches
Compression Ratio: 9.5:1
Operating Range: 2,000 to 12,000 RPM
HP: 1.5 @ 11,000
Weight: 17.9 oz. 501g (including Silencer)
Distance between mounting holes (width): 44mm
Total length: 97mm
I needed a motor to replace my old Irvine 53, I wanted good throttling, power to turn a big prop, and most of all reliability in the air (don’t want much do I?).
I looked to the “Super Stars” to see what motors they use, and the YS came top of the list. With Father Christmas just about to arrive, the telephone number of Probuild and the part number were left in several places where my wife would find it!
At first glance the YS motors look like a normal four-stroke model aircraft engine. They have the usual rocker box on top, push rod tubes at the front, and a carb at the rear.
The first thing you notice that makes you realise this is no ordinary motor are the fuel pipes going into places, where pipes have never gone before. The fuel feed (for want of a name) to the Carb does not go to the tank, but to a nipple near the front of the motor. In the same area there are two other nipples that look similar to the pumps fitted to old OS four strokes. These nipples are not connected to a fuel pump as we know it, but one is effectively an air pump, the other is the “fuel in” feed to the fuel regulator.
By now you will start to realise that this is just a little more than your usual model engine. On closer inspection you start to notice that many other things are not what they seem. What looks like a Carburettor on the back of the motor does not have the usual straight flow through a barrel, and into the inlet; instead it uses a butterfly valve similar to “normal” carburettors seen on Cars and bikes.
The fuel-air mixture is taken into the back end of the motor before being forced into the inlet manifold. Yes I did say forced, the secret behind these amazing motors is that they are super-charged. Using the pistons down stroke, the mixture is compressed before being forced into the motor. This sound familiar? It should, as it’s basically the same process used by all two strokes.
This is not the only secret the YS hides, the reason for the complicated fuel system is that it has a very simple but effective fuel injection system. Some of the pressure from the crankcase is released via the pressure nipple on the front of the motor to the tank. This pipe has a one way valve that allows this pressure to be “stored” in the tank at between 6-9psi. The fuel in the tank is then forced out to feed the motor. Fuel feed to the motor is taken from the tank and into the remaining nipple at the front of the motor, where the fuel regulator only allows fuel to pass to the injector body when the motor is running over 2000 rpm. A needle controls the amount of fuel allowed into the motor in the same way as a usual carb, but is FAR more sensitive, with the correct setting being only one or two clicks either way. What is great about this system is that once set, you just leave it alone. Idle is set in the usual way, but must be done below 2000 rpm, and at this point the fuel system returns to the normal arrangement of sucking the fuel into the motor.
Using the YS 63
The first thing I was very happy to discover is that the YS63 uses exactly the same mounting as the Irvine 53 / OS 46 and a host of other 40 – 46 motors, so it was a 10-minuet job to get the motor in the model. Unfortunately the rest of the installation needs a bit more thought.
The throttle leaver is on the same side as the Irvine (Left looking from the front) and just required the servo connection shortened and modified a little (Bent with a big pair of pliers)
The fuel supply needs a total overhaul. The pipes to a YS can easily resemble ball of wool after a kitten has played with it!! So take your time and invest in some nice small cable ties. Coloured fuel pipes help with future maintenance.
First you need a supply pipe from the tank to the regulator, and this must be fitted with a fuel filter. Second pipe is fitted from the pump on the front of the motor to the vent of the tank, this has to have a one way valve (supplied with the motor) to keep the tank pressurised.
On each of these pipes a "T" piece has to be added to fill the tank. One in the Supply pipe is used to fill, and the second "T" is fitted to the pressure pipe to allow the tank to vent as it is filled. I chose to replace the "T" in the supply pipe with a fuelling valve (the type that you push in a special metal tube to fill the model). I already had a third pipe attached to the tank for filling the model, rather than blocking this off I used this as the vent.
As I mentioned earlier the fuel system is pressurised, YS say this is between 6 and 9 PSI. I decided to see if my tank (Dubro 10oz) would be OK with this pressure and also if the push on silicone pipes would stay in place. Using a bike pump and pressure gauge I fitted some dummy pipes and pressurised the tank to 15psi with no problems. As a precaution I have added a "sleeve" of silicone tubing over the actual tubing everywhere it is pushed onto a connection. This is a good precaution even on a "normal" fuel system.
One thing to be aware of, after the motor has been run the tank remains pressurised. When you come to refill the model be careful opening the vent pipe as you may get a face of fuel. (Don’t ask how I found out!!)
One of the big advantages of using a pumped or pressurised fuel system is that you can to move the tank over the C of G or at least much closer. With the tank over the C of G it allows you to trim the model with a full tank and once set you don’t need to adjust the trim as the fuel burns off. This is not a problem in your average trainer, but in models like Caps/ Extra etc, where they are set with the C of G pretty close to the limit the handling does change quite significantly.
The YS does need some getting used to and the starting procedure needs to be followed to avoid frustration!! With the glow clip removed; first close the throttle and spin the motor ten revolutions, this pressurises the tank. Then open the throttle to full and spin the motor for another ten revolutions to prime the motor. The starting technique as shown on the YS web suggests starting the motor at idle, but I found it needs the throttle to be opened just bellow a ¼ and then it starts easy. Apparently YS motors prefer to start using a starter motor. I found that as long as you followed the procedure, a reverse flick works well, but watch your fingers if it kicks back! YOU HAVE BEEN WARNED Under NO circumstances should a YS be started with the throttle at more than a ¼. As this motor is injected it may just keep running!!
The instructions tell you to open the main needle two turns, I tried this and the motor would not pick up and was far too rich. Once I closed the main needle to about 1 turns it picked up perfectly.
The instructions said to find the peak at full throttle on the main jet then wind it open 3-4 clicks. The only four-stroke plug I had available was an ASP version, with this plug it made the main needle setting incredibly hard to find, just one click either way would have the motor cut. The only plugs that work on this motor are YS’s own or the OS FS plugs. Once I changed to an OSFS the motor was far easier to set, so don’t try to skimp with cheap plugs.
One thing I have noticed on the YS is pre-ignition if the motor is too lean. I was trying to find the "sweet spot" on the main needle and noticed that you can go a long way lean before the motor looses a few RPM. The only tell tail is a rattle or pinking sound from the motor. I did a bit of homework (playing on the web) and discovered that this is the primary cause of damage to the bigger YS 1.40. At worst it is possible to destroy the motor completely, but even easier to burn out a valve. This is not covered in the YS manual or on the Pro-build web site. It is covered in detail on the YS USA web page www.ysperformance.com. Look at the Tech Tips link.
What concerned me was the "rattle" is not easy to notice, but its worth keeping an eye out (or should that be an ear out) for the tell tail rattle. It could cost you a fortune! If you follow the instructions of find the peak, then open the needle 3 clicks, it will seam rich, but will be fine in the air.
Running in a ringed motor is some what easier on the ears than an ABC motor, as it needs to be run fairly slow for the first few minutes, rather than full throttle of an ABC. I gave the motor 20min (1½ tanks) on the ground with the cowl removed varying between Idle, half and full throttle.
See Part two
.
Bore: 26.16 mm
Stroke: 19 mm
Displacement: .623 cubic inches
Compression Ratio: 9.5:1
Operating Range: 2,000 to 12,000 RPM
HP: 1.5 @ 11,000
Weight: 17.9 oz. 501g (including Silencer)
Distance between mounting holes (width): 44mm
Total length: 97mm
I needed a motor to replace my old Irvine 53, I wanted good throttling, power to turn a big prop, and most of all reliability in the air (don’t want much do I?).
I looked to the “Super Stars” to see what motors they use, and the YS came top of the list. With Father Christmas just about to arrive, the telephone number of Probuild and the part number were left in several places where my wife would find it!
At first glance the YS motors look like a normal four-stroke model aircraft engine. They have the usual rocker box on top, push rod tubes at the front, and a carb at the rear.
The first thing you notice that makes you realise this is no ordinary motor are the fuel pipes going into places, where pipes have never gone before. The fuel feed (for want of a name) to the Carb does not go to the tank, but to a nipple near the front of the motor. In the same area there are two other nipples that look similar to the pumps fitted to old OS four strokes. These nipples are not connected to a fuel pump as we know it, but one is effectively an air pump, the other is the “fuel in” feed to the fuel regulator.
By now you will start to realise that this is just a little more than your usual model engine. On closer inspection you start to notice that many other things are not what they seem. What looks like a Carburettor on the back of the motor does not have the usual straight flow through a barrel, and into the inlet; instead it uses a butterfly valve similar to “normal” carburettors seen on Cars and bikes.
The fuel-air mixture is taken into the back end of the motor before being forced into the inlet manifold. Yes I did say forced, the secret behind these amazing motors is that they are super-charged. Using the pistons down stroke, the mixture is compressed before being forced into the motor. This sound familiar? It should, as it’s basically the same process used by all two strokes.
This is not the only secret the YS hides, the reason for the complicated fuel system is that it has a very simple but effective fuel injection system. Some of the pressure from the crankcase is released via the pressure nipple on the front of the motor to the tank. This pipe has a one way valve that allows this pressure to be “stored” in the tank at between 6-9psi. The fuel in the tank is then forced out to feed the motor. Fuel feed to the motor is taken from the tank and into the remaining nipple at the front of the motor, where the fuel regulator only allows fuel to pass to the injector body when the motor is running over 2000 rpm. A needle controls the amount of fuel allowed into the motor in the same way as a usual carb, but is FAR more sensitive, with the correct setting being only one or two clicks either way. What is great about this system is that once set, you just leave it alone. Idle is set in the usual way, but must be done below 2000 rpm, and at this point the fuel system returns to the normal arrangement of sucking the fuel into the motor.
Using the YS 63
The first thing I was very happy to discover is that the YS63 uses exactly the same mounting as the Irvine 53 / OS 46 and a host of other 40 – 46 motors, so it was a 10-minuet job to get the motor in the model. Unfortunately the rest of the installation needs a bit more thought.
The throttle leaver is on the same side as the Irvine (Left looking from the front) and just required the servo connection shortened and modified a little (Bent with a big pair of pliers)
The fuel supply needs a total overhaul. The pipes to a YS can easily resemble ball of wool after a kitten has played with it!! So take your time and invest in some nice small cable ties. Coloured fuel pipes help with future maintenance.
First you need a supply pipe from the tank to the regulator, and this must be fitted with a fuel filter. Second pipe is fitted from the pump on the front of the motor to the vent of the tank, this has to have a one way valve (supplied with the motor) to keep the tank pressurised.
On each of these pipes a "T" piece has to be added to fill the tank. One in the Supply pipe is used to fill, and the second "T" is fitted to the pressure pipe to allow the tank to vent as it is filled. I chose to replace the "T" in the supply pipe with a fuelling valve (the type that you push in a special metal tube to fill the model). I already had a third pipe attached to the tank for filling the model, rather than blocking this off I used this as the vent.
As I mentioned earlier the fuel system is pressurised, YS say this is between 6 and 9 PSI. I decided to see if my tank (Dubro 10oz) would be OK with this pressure and also if the push on silicone pipes would stay in place. Using a bike pump and pressure gauge I fitted some dummy pipes and pressurised the tank to 15psi with no problems. As a precaution I have added a "sleeve" of silicone tubing over the actual tubing everywhere it is pushed onto a connection. This is a good precaution even on a "normal" fuel system.
One thing to be aware of, after the motor has been run the tank remains pressurised. When you come to refill the model be careful opening the vent pipe as you may get a face of fuel. (Don’t ask how I found out!!)
One of the big advantages of using a pumped or pressurised fuel system is that you can to move the tank over the C of G or at least much closer. With the tank over the C of G it allows you to trim the model with a full tank and once set you don’t need to adjust the trim as the fuel burns off. This is not a problem in your average trainer, but in models like Caps/ Extra etc, where they are set with the C of G pretty close to the limit the handling does change quite significantly.
The YS does need some getting used to and the starting procedure needs to be followed to avoid frustration!! With the glow clip removed; first close the throttle and spin the motor ten revolutions, this pressurises the tank. Then open the throttle to full and spin the motor for another ten revolutions to prime the motor. The starting technique as shown on the YS web suggests starting the motor at idle, but I found it needs the throttle to be opened just bellow a ¼ and then it starts easy. Apparently YS motors prefer to start using a starter motor. I found that as long as you followed the procedure, a reverse flick works well, but watch your fingers if it kicks back! YOU HAVE BEEN WARNED Under NO circumstances should a YS be started with the throttle at more than a ¼. As this motor is injected it may just keep running!!
The instructions tell you to open the main needle two turns, I tried this and the motor would not pick up and was far too rich. Once I closed the main needle to about 1 turns it picked up perfectly.
The instructions said to find the peak at full throttle on the main jet then wind it open 3-4 clicks. The only four-stroke plug I had available was an ASP version, with this plug it made the main needle setting incredibly hard to find, just one click either way would have the motor cut. The only plugs that work on this motor are YS’s own or the OS FS plugs. Once I changed to an OSFS the motor was far easier to set, so don’t try to skimp with cheap plugs.
One thing I have noticed on the YS is pre-ignition if the motor is too lean. I was trying to find the "sweet spot" on the main needle and noticed that you can go a long way lean before the motor looses a few RPM. The only tell tail is a rattle or pinking sound from the motor. I did a bit of homework (playing on the web) and discovered that this is the primary cause of damage to the bigger YS 1.40. At worst it is possible to destroy the motor completely, but even easier to burn out a valve. This is not covered in the YS manual or on the Pro-build web site. It is covered in detail on the YS USA web page www.ysperformance.com. Look at the Tech Tips link.
What concerned me was the "rattle" is not easy to notice, but its worth keeping an eye out (or should that be an ear out) for the tell tail rattle. It could cost you a fortune! If you follow the instructions of find the peak, then open the needle 3 clicks, it will seam rich, but will be fine in the air.
Running in a ringed motor is some what easier on the ears than an ABC motor, as it needs to be run fairly slow for the first few minutes, rather than full throttle of an ABC. I gave the motor 20min (1½ tanks) on the ground with the cowl removed varying between Idle, half and full throttle.
See Part two
.
03-07-2003, 01:00 PM
#2
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Thread Starter
Join Date: Dec 2002
Location: Wellingborough, UNITED KINGDOM
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Yamada YS 63 part two
The first flight was in my Glens 58” Cap and it showed the potential of the motor. Takeoff was as usual with wheels off in 15ft!! This model weighs about 5 3/4 lbs. I don’t know who is telling lies, as YS is supposed to be 100g heavier than the Irvine 53 it replaced, but the model only gained 1½ oz, is the YS light or is the Irvine heavy!!
The motor was fitted with the same APC 12 x 6 prop as the Irvine had used as I didn’t want to load it up for the first few runs of its life. With the 12 x 6 prop it did not have the vertical performance of the Irvine 53, but given that this motor likes to be loaded rather than revved it was not unexpected. I took the first flight fairly easy with only a couple of vertical climbs to see how it performed. The most impressive difference with the motor is its pick up. Apart from still being a bit rich, it was instantaneous, and the slow idle amazing.
For the next outing I changed the prop to a RAM 13 x 6 and what a difference it made. It had more power than the Irvine I that it could prop hang at ½ throttle and then accelerate vertically with just a blip of throttle.
Now comes the down side!! It is a very expensive motor to own. OK given it has the power of many 90 four-strokes and more than a few 60 two-strokes at £210 its not too bad. The expensive bit is feeding its hunger, not that its thirsty at under 1 oz per minuet, but it’s the type of fuel that’s the problem.
YS insist on fuel with at least 18% fully synthetic oil, and preferably with 20% nitro! This costs about £24 per gallon in a special mix from Model Technics, but you can use as low as 10% nitro.
For the flights I have done so far I have used my usual Coolpower 10% fuel, I am told this is sufficient, but the motor does work better with 20% nitro.
I now use the YS in a Zen 50 that weighs in at 6lbs 3oz using an APC 12 x 7 prop it has more than enough power to prop hang and still have power to climb away.
After 12 flights/2 hours I noticed the power had dropped off and the midrange was not as clear as I like. A quick note to YS support on here solved both.
The power was restored by checking and re-setting the Valve clearences. The YS seams to be quite sensertive to the valve settings, so keep an eye on them. Once they had been re-set, they did not change much after the nest hour of running.
The midrange problem seams to be a common situation with the 63 judging from the amounts of questions on here regarding the mid range. Again the YS support helped out with the following set up instructions.
1. Reset the idle screw to 1.5 turns open.
2. Reset the reg screw to flush with the casting. The best way of checking this is with a steal rule across the casting and screw the regulator out till it touches the rule.
3. Start the engine at just above idle and let it run for 30 seconds.
4. Go to full throttle and set the high end. The needle should be open about 2 turns to start and should be about 1.5 turns open when set correctly.
5. Go back to idle for 15 seconds and note which way the engine wants to go, lean or rich and adjust the idle accordingly.
6. Then advance the throttle and note the transition, too lean open the reg screw 1/4 turn at a time to richen. If too rich go in 1/4 at a time.
I followed these instructions and the motor is realy clean throughout the rev range.
This motor has the same feel as the petrol motors I have. Its throttle-ability is stunning as well as instant power on tap. One thing for sure, it has converted me, and look at four strokes in a totally different light.
The motor was fitted with the same APC 12 x 6 prop as the Irvine had used as I didn’t want to load it up for the first few runs of its life. With the 12 x 6 prop it did not have the vertical performance of the Irvine 53, but given that this motor likes to be loaded rather than revved it was not unexpected. I took the first flight fairly easy with only a couple of vertical climbs to see how it performed. The most impressive difference with the motor is its pick up. Apart from still being a bit rich, it was instantaneous, and the slow idle amazing.
For the next outing I changed the prop to a RAM 13 x 6 and what a difference it made. It had more power than the Irvine I that it could prop hang at ½ throttle and then accelerate vertically with just a blip of throttle.
Now comes the down side!! It is a very expensive motor to own. OK given it has the power of many 90 four-strokes and more than a few 60 two-strokes at £210 its not too bad. The expensive bit is feeding its hunger, not that its thirsty at under 1 oz per minuet, but it’s the type of fuel that’s the problem.
YS insist on fuel with at least 18% fully synthetic oil, and preferably with 20% nitro! This costs about £24 per gallon in a special mix from Model Technics, but you can use as low as 10% nitro.
For the flights I have done so far I have used my usual Coolpower 10% fuel, I am told this is sufficient, but the motor does work better with 20% nitro.
I now use the YS in a Zen 50 that weighs in at 6lbs 3oz using an APC 12 x 7 prop it has more than enough power to prop hang and still have power to climb away.
After 12 flights/2 hours I noticed the power had dropped off and the midrange was not as clear as I like. A quick note to YS support on here solved both.
The power was restored by checking and re-setting the Valve clearences. The YS seams to be quite sensertive to the valve settings, so keep an eye on them. Once they had been re-set, they did not change much after the nest hour of running.
The midrange problem seams to be a common situation with the 63 judging from the amounts of questions on here regarding the mid range. Again the YS support helped out with the following set up instructions.
1. Reset the idle screw to 1.5 turns open.
2. Reset the reg screw to flush with the casting. The best way of checking this is with a steal rule across the casting and screw the regulator out till it touches the rule.
3. Start the engine at just above idle and let it run for 30 seconds.
4. Go to full throttle and set the high end. The needle should be open about 2 turns to start and should be about 1.5 turns open when set correctly.
5. Go back to idle for 15 seconds and note which way the engine wants to go, lean or rich and adjust the idle accordingly.
6. Then advance the throttle and note the transition, too lean open the reg screw 1/4 turn at a time to richen. If too rich go in 1/4 at a time.
I followed these instructions and the motor is realy clean throughout the rev range.
This motor has the same feel as the petrol motors I have. Its throttle-ability is stunning as well as instant power on tap. One thing for sure, it has converted me, and look at four strokes in a totally different light.
