YS Engines
Me
under the impression that YS made a 1.2 Supercharged engine, which is
actually their Air Chamber engine that uses a rotary valve to pressurize the
intake tract. (Not really a mechanical supercharger, but close, and the
engine makes buku horsepower) They also made a number of 1.2 engines that do
not have the AC designation. I found one that the box says "Supercharged"
and "Pressurized Fuel System" but it does not have an Air Chamber. I take
it that these engines are not supercharged?
Thanks
Bill
Paul McIntosh
provide more than atmospheric pressure to the combustion chamber when the
intake valve opens. Also, they use a pressureized fuel tank system for fuel
delivery. You need to use high quality tanks and wrap them with filament
tape for safety.
--
Paul McIntosh
http://www.rc-bearings.com
"Me" <bhei...@iwon.com> wrote in message
news:ouedneBTvp0...@yvn.com...
Dr1Driver
>it that these engines are not supercharged?
Correct. All YS engines have a pressurized fuel delivery. They operate off a
vibrating reed valve. It is most effective in the lower half of the RPM range.
YS engines are extremely powerful but heavy. You also need some care for the
reed valve. If you don't fly but once every couple weeks, the valve tends to
gum up and must be cleaned. If you don't know this, tuning the engine is very
frustrating.
Dr.1 Driver
"There's a Hun in the sun!"
Bill
we have had a few guys use them, most of the time with some problems.
"Dr1Driver" <dr1d...@aol.com> wrote in message
news:20040324075844...@mb-m05.aol.com...
Courseyauto
"Dr1Driver" <dr1d...@aol.com> wrote in message
news:20040324075844...@mb-m05.aol.com...
> > I take
> >it that these engines are not supercharged?
>
> Correct. All YS engines have a pressurized fuel delivery. They operate
off a
> vibrating reed valve. It is most effective in the lower half of the RPM
range.
>
> YS engines are extremely powerful but heavy. You also need some care for
the
> reed valve. If you don't fly but once every couple weeks, the valve tends
to
> gum up and must be cleaned. If you don't know this, tuning the engine is
very
> frustrating.
>
>
> Dr.1 Driver
> "There's a Hun in the sun!"
Could you please tell me where this vibrating reed valve is located?
Greg
> >it that these engines are not supercharged?
>
> Correct. All YS engines have a pressurized fuel delivery. They operate
off a
> vibrating reed valve. It is most effective in the lower half of the RPM
range.
>
All YS strokes are "supercharged". Are you referring to the pump diaphragm
as a reed valve?
> YS engines are extremely powerful but heavy. You also need some care for
the
> reed valve. If you don't fly but once every couple weeks, the valve tends
to
> gum up and must be cleaned. If you don't know this, tuning the engine is
very
> frustrating.
>
While a lot of troubles tend to center around the pump diaphragm, good
quality clean fuel tends to eliminate that problem. I've had engines that
have set for over 6 months without problems. Most problems I've seen are a
result of people using the incorrect fuel/oil combinations and the cheapest
available.
Greg
All YS 4 stroke series are "supercharged"...from the .53 through the 1.40.
The air chamber was only included on the 1.20's for a short time. The only
engine in their series with it today is the .91/1.10 series.
If you're looking at a 1.20 AC, parts are getting hard to come by. The
1.20 AC was a short run (probably around 6 months) and then they came out
with the 1.20 SC. You'd have a hard time finding parts for the AC.
If you're looking for a version that's easiest to set (for sport flying),
try the 1.20 NC or FZ.
Follow the instructions, especially in the fuel recommendation section.
Here's a couple sites if you haven't seen them yet.
http://www.ysperformance.com/
http://www.probuild-uk.co.uk/factsheets/ys_engines.php
Greg
Dr1Driver
This applies to 2-strokes only, I've had no experience with YS 4-stroke
engines.
On the bottom of the crankshaft journal, under the carb, is an adjustable brass
screw. The valve/diaphragm is under it. The screw is used for adjusting fuel
pressure at lower speeds.
The other post(s) concerning clean vs. dirty fuel are correct. You must use
high quality fuel and filter it well.
Bill
I bought a 91AC at a swap meet on Saturday for next to nothing since it had
no compression. I took it apart and found the valves and lifters stuck open.
The intake valve was fairly easy to free up, but not so the exhaust valve.
Using a combination of penetrating oil and gentle persuasion, I did manage
to close it. I removed the keepers and worked the valve out of the head.
Lots of carbon. I think that this engine is salvageable by putting in a set
of gaskets and bearings, probably replace the ring while it's apart. If it
is, it will be the second 4-stroke I have brought back to life that someone
else gave up on. At this rate, the guys in the club won't be selling me any
more engines. ;>)
Bill
"Greg" <garn...@notsohotmail.com> wrote in message
news:10801523...@news.commspeed.net...
Bill
has milled slots for a spanner wrench, and in the parts breakdown it appears
to be threaded. Also, any particular trick to removing the bearings, besides
the usual "warm up the crankcase?"
Thanks
Bill
"Me" <bhei...@iwon.com> wrote in message
news:ouedneBTvp0...@yvn.com...
Paul McIntosh
blended 20/20 YS fuel. Using fuel with a lot of castor can lead to what you
saw in your engine.
Once set up, you will find that this engine is very powerful and reliable.
They are also easy to tune, contrary to others opinions. Most problems are
from failure to follow directions (like Fox "problems").
My oldest one is approaching 11 years old and it has had only minor
maintenance done in that time.
--
Paul McIntosh
http://www.rc-bearings.com
"Bill" <bheinso...@iwon.com (Remove the obvious)> wrote in message
news:HeidnSa0hKH...@yvn.com...
Paul McIntosh
the seal and O-ring from the crankcase first.
The liner isn't threaded. It just slides out.
--
Paul McIntosh
http://www.rc-bearings.com
"Bill" <bheinso...@iwon.com (Remove the obvious)> wrote in message
news:3fSdnXMjW_i...@yvn.com...
John Hawkins
(Remove the obvious)> wrote:
>Has anyone been into a YS 91? I am wondering about removing the sleeve. It
>has milled slots for a spanner wrench, and in the parts breakdown it appears
>to be threaded. Also, any particular trick to removing the bearings, besides
>the usual "warm up the crankcase?"
>Thanks
>Bill
>
>
The screw in liner and head used to be replaced as an
assembly. I believe it came with the rocker arm assembly installed as
well. This is one of the first iterations. While still called the AC
later versions reverted to a conventional liner. Not sure about parts
availability. Usual sources are YS Performance Specialties, Central
Hobbies, Radio South. The LHS has used Great Planes as a source. I
replaced the sleeve once quite a while back after striking the muffler
and breaking the head. This is real easy to do with the muffler that
sticks straight out.
For answers straight from the horse's mouth go to the engine
manufacturers forum on RCU and ask Dave Shadel.
John Hawkins - From Canada's Atlantic Coast
http://rcalbum.rchomepage.com/Home.html
Paul McIntosh
When did they change? Mine is 11 years old and has the slide in liner.
--
Paul McIntosh
http://www.rc-bearings.com
"John Hawkins" <joh...@hotmail.com> wrote in message
news:f04460tnnr48dr8gr...@4ax.com...
John Hawkins
<pa...@mcintoshcentral.com> wrote:
>John,
>
>When did they change? Mine is 11 years old and has the slide in liner.
I don't know how soon after introduction of the 91 that they
dropped the screw in liner but it seems it wasn't long. I ordered the
engine when they first came out and had to wait for stock so I presume
it was one of the first to be distributed. Dave Shadel has hinted
that he doesn't think much of them. Although he didn't say why I
suspect he would be candid if asked. Mine has been fine but it
doesn't have high time. I bought a second one of the same arrangement
from a friend and it is going strong. Ironically a FZ bought new was
the most problematic. Until they modified them some had problems with
excessive blow-by screwing up the regulator.
John Hawkins
> Could you please tell me where this vibrating reed valve is located?
There is none as you likely know..
The fuel tank is pressurized by timed crankcase pressure
pulses ported through the crank. The pulses pass through a chamber
and act on the top of a diaphragm in the regulator and then through a
check valve to the tank.. Fuel from the tank enters the bottom of the
regulator and passes through a port opened and closed by a plunger
operated by case pressure acting on the diaphragm mentioned above.
This is opposed by adjustable spring pressure. At idle the regulator
is inoperative and fuel flow is governed by venturi vacuum and an air
bleed. Similarly at wide open throttle the plunger is constantly open
and mixture is governed by the high speed needle. The regulator
governs fuel flow in between. Constant fuel pressure allows the
engine run consistently, independent of fuel head variations that come
tank location in the fuse or in manoeuver, or as fuel is consumed.
Courseyauto
I know theres no vibrating reedvalve,i just wanted to see what he had to say.
I know how the system works and it,s basicly the same on 4 strokes. The 91 and
80 helicopter motors now use crankcase pressure to pressurize the tank.
I have one of the 91 4 stroke motors with the screw in linner thats brand new
in the box,i got it from my brother who bought it when thet first came out.
They were quite expensive too a lot more than the new FZ 91 out now,
ibelieve he paid over $300 for it I have one of the 63 4 strokes that has
been a lot of problems, i sent it back twice to performance specialties but it
still doesnt run right. They now have a fix that involves putting gas ports
in the piston to help seal the ring which i'll send the piston to him so he
can do it. The new 63 has the reg moved because they say in the old position
it got to hot causing problems,i dont believe it because mine was totally open
to cooling and i still had problems. I have just about every YS made, a little
more complicated but probably the best engine made. DOUG
Bill
I just stripped the engine down to have everything cleaned. I removed the
intake valve and discovered that YS drilled four holes through the intake
port to the crankcase, under the intake valve spring. ???? This must be part
of their supercharged feature and explains why it is so important that the
engine be perfectly sealed. Over the last forty years, I have disassembled a
LOT of engines. (From Boss 429 Fords, down to Saito 50's) I have never seen
anyone do this.
After cleaning, what is the accepted way to lap in the valves? (Or, should
this even be done?) I have herd guy using anything from toothpaste to fine
lapping compound. Personally, I try to avoid having anything like this
inside an engine. No matter how well you clean it, there is always the
possibility of some of it being there when you start the engine
Thanks
Bill
"John Hawkins" <joh...@hotmail.com> wrote in message
news:f04460tnnr48dr8gr...@4ax.com...
Paul McIntosh
chamber.
I wouldn't lap the valves unless there is evidence that they weren't sealing
properly.
--
Paul McIntosh
http://www.rc-bearings.com
"Bill" <bheinso...@iwon.com (Remove the obvious)> wrote in message
news:YtadnZvM3fH...@yvn.com...
Boo
> engine in their series with it today is the .91/1.10 series.
I'm interested to know what is/was the point of the air chamber on these
engines ? And why they don't make them all with this feature ?
--
Boo
Bill
we talking about? How does this compare to the roots type blower that was on
the OS 1.20? Some of the YS 1.20 engines put out more power than others. I
suspect that it has to do with user friendliness. A 195 H.P. 302 is a lot
more forgiving and user friendly than a Boss 302.
One thing that I have noticed but have not had the time to completely
explore. Parts prices for YS engines seem to be less than Saito engines.
This would go a long way if a guy was thinking about switching brands.
"Boo" <boo@spam_me_no_spam.net> wrote in message
news:c3vacl$hbo$1...@newsg2.svr.pol.co.uk...
Mike
> I would be curious about that also. How much boost in the intake tract are
> we talking about? How does this compare to the roots type blower that was
on
> the OS 1.20? Some of the YS 1.20 engines put out more power than others.
I
> suspect that it has to do with user friendliness. A 195 H.P. 302 is a lot
> more forgiving and user friendly than a Boss 302.
> One thing that I have noticed but have not had the time to completely
> explore.
>Parts prices for YS engines seem to be less than Saito engines.
>This would go a long way if a guy was thinking about switching brands.
What you say about the Saito/YS parts price comparison is true. However,
please factor in the frequency of need for parts with each brand.
Happy Flying,
Mike
Greg
"Bill" <bheinso...@iwon.com (Remove the obvious)> wrote in message
news:YtadnZvM3fH...@yvn.com...
> John
> I just stripped the engine down to have everything cleaned. I removed the
> intake valve and discovered that YS drilled four holes through the intake
> port to the crankcase, under the intake valve spring. ???? This must be
part
> of their supercharged feature and explains why it is so important that the
> engine be perfectly sealed. Over the last forty years, I have disassembled
a
> LOT of engines. (From Boss 429 Fords, down to Saito 50's) I have never
seen
> anyone do this.
> After cleaning, what is the accepted way to lap in the valves? (Or, should
> this even be done?) I have herd guy using anything from toothpaste to fine
> lapping compound. Personally, I try to avoid having anything like this
> inside an engine. No matter how well you clean it, there is always the
> possibility of some of it being there when you start the engine
> Thanks
> Bill
>
Bill, we've used fine valve lapping compound with added oil for lapping the
valves when needed. Clean up with methanol....lots of it.
Greg
Greg
Evidently, they aren't necessary. Good question though. I know of a guy
that blocked off the air chamber on a .91 so it would only flow through to
as close as a straight shot as possible and it didn't make a difference in
performance.
Balancing impulses to just using the same castings are the range of answers
I've heard from people over the years. I'd really like an affirmative
answer myself.
Greg
John Hawkins
<garn...@notsohotmail.com> wrote:
>
>"Bill" <bheinso...@iwon.com (Remove the obvious)> wrote in message
>news:YtadnZvM3fH...@yvn.com...
>> After cleaning, what is the accepted way to lap in the valves? (Or, should
>> this even be done?) I have herd guy using anything from toothpaste to fine
>> lapping compound. Personally, I try to avoid having anything like this
>> inside an engine. No matter how well you clean it, there is always the
>> possibility of some of it being there when you start the engine
>> Thanks
>> Bill
>>
>snip
>
>Bill, we've used fine valve lapping compound with added oil for lapping the
>valves when needed. Clean up with methanol....lots of it.
>
>Greg
>
Clarence Lee cautions not to use auto valve grinding compound
for the reasons Bill Suggests. I can't remember what he suggests as
an alternative although I suspect it may be toothpaste. He suggests
that the abrasive will embed in the particular metals used in model
construction. Don't know myself - just pointing out his observation.
Greg
Too many brands & styles to choose from...
Simply White Advanced Whitening Toothpaste,
Colgate Total Plus Whitening,
Colgate Fresh Confidence,
Colgate 2in1 Icy Blast whitening,
Colgate Sparkling White with tartar control,
Colgate Sparkling White with baking soda & peroxide,
Colgate tartar control plus whitening gel cool mint gel,
Colgate tartar control plus whitening Crisp Mint paste,
Colgate Platinum whitening mild mint,
Colgate Platinum whitening winter mint,
Colgate 2in1 whitening,
Colgate 2in1 fresh mint,
Colgate Total Advanced Fresh 2in1,
Colgate Herbal White,
Colgate Sensitive Maximum Strength plus whitening,
Colgate Sparkling White with baking soda & peroxide,
Colgate baking soda & peroxide whitening with tartar control Brisk Mint
Paste,
Colgate baking soda & peroxide whitening with tartar control Frosty Mint
Striped Gel,
Colgate tartar control with baking soda & peroxide clean mint,
Colgate 2in1 Kids Toothpaste and Mouthwash,
Colgate Barbie* Sparkling Bubble Fruit toothpaste,
Colgate Looney Tunes* Bubble fruit,
WildMint and Berrylicious,
My First Colgate BABY LOONEY TUNES,
Mild Bubble Fruity toothpaste,
Masters of the Universe* Power BubbleT flavor toothpaste,
Colgate The Powerpuff Girls toothpaste, etc.
Personally, I'd lean toward the Masters of the Universe Power Bubble flavor
just for the cool pictures on the tube. I'm guessing a good all-around
anti-cavity plus tartar control would do the trick. :o)
Seriously though, was it possibly Semi-chrome polish Clarence suggested?
Have a good weekend....
Greg
Bill
think the key is finding a water soluble lapping compound. Clover brand
automotive/industrial lapping compound it silicone carbide, in oil. The very
last thing we need is silicone carbide floating around inside an engine.
"Greg" <garn...@notsohotmail.com> wrote in message
news:10803197...@news.commspeed.net...
Paul McIntosh
for crash repair. Any engine will last a long time if taken care of.
--
Paul McIntosh
http://www.rc-bearings.com
"Mike" <gla...@yahoo.com> wrote in message
news:1066m1b...@corp.supernews.com...
Bob
You have too much time on your hands!!! :-)
Thanks for the laughs,
Bob Scott
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Bob
lower nitro? If I bought a YS and ran it on "10/20" or "15/20" would it run
OK?
I'm starting to look at engines for a Dave Patrick Ultimate and would like
to try my first YS. I have four-cycles from Saito, O.S. and Magnum and they
run fine on whatever I feed 'em. Will a YS do the same? Right now I'd say
I'm a Saito fan and wouldn't have any problem buying a new 1.50 for the
Ultimate. I'd like to try the YS 1.40 though....
And is there a mail-order business known for the best prices on YS engines?
Thanks for any information,
Greg
the cutting and pasting frenzy on self-induced hypoglycemic shock syndrome
stemming from too many glazed doughnuts and multiple cups of coffee.
Sometimes, we just gotta' laugh. Life's to short.
Greg
"Bob" <desm...@capital.net> wrote in message
news:4064a...@corp.newsgroups.com...
Paul McIntosh
with plenty of oil as the lower end is lubed by the fuel mix rather than
blowby. What this means is the oil doesn't have the chance to accumulate
like regular four strokes.
--
Paul McIntosh
http://www.rc-bearings.com
"Bob" <desm...@capital.net> wrote in message
news:4064e...@corp.newsgroups.com...
pcoopy
this time but used 15% Omega for a long time with good results. YS's
are very powerful due to their supercharging system but they are also
quite heavy for their size. I also have a DPM Ultimate and find the
Saito 150 to be a good choice because it has a lot of midrange torque
and will swing a big low pitch prop, an advantage for the type of
flying you will want to do with the DPM Ultimate.
Phil AMA609
"Bob" <desm...@capital.net> wrote in message news:<4064e...@corp.newsgroups.com>...
Greg
> lower nitro? If I bought a YS and ran it on "10/20" or "15/20" would it
run
> OK?
>
> I'm starting to look at engines for a Dave Patrick Ultimate and would like
> to try my first YS. I have four-cycles from Saito, O.S. and Magnum and
they
> run fine on whatever I feed 'em. Will a YS do the same? Right now I'd
say
> I'm a Saito fan and wouldn't have any problem buying a new 1.50 for the
> Ultimate. I'd like to try the YS 1.40 though....
>
> And is there a mail-order business known for the best prices on YS
engines?
>
> Thanks for any information,
> Bob Scott
>
Here's a couple sites to check on prices....
http://www.centralhobbies.com/Engines/ys/index.htm
http://tinyurl.com/28sah
You might want to check with your LHS. Ours can normally beat these prices.
Just out of curiosity, are you leaning towards the 1.4 Sport or 1.4 DZ? The
DZ will be replaced in May with the 1.6. We have 2 of the 1.4DZ's running
now and they are VERY impressive! On a H9 100" Cub, it will hover around
1/3 throttle. No doubt expensive, but you get what you pay for.
Greg
Bob
> Here's a couple sites to check on prices....
>
> http://www.centralhobbies.com/Engines/ys/index.htm
> http://tinyurl.com/28sah
>
> You might want to check with your LHS. Ours can normally beat these
prices.
>
> Just out of curiosity, are you leaning towards the 1.4 Sport or 1.4 DZ?
The
> DZ will be replaced in May with the 1.6. We have 2 of the 1.4DZ's running
> now and they are VERY impressive! On a H9 100" Cub, it will hover around
> 1/3 throttle. No doubt expensive, but you get what you pay for.
Thanks for the leads, Greg.
I was interested in the Sport. (limited budget) Actually, I didn't really
feel the need for a 1.40 and would have been happy with a 1.20. Now, the
1.20 is a 1.40, soon to be a 1.60. Maybe the .91, now a 1.10, will soon be
a 1.20? =:-0
Good flying,
Greg
>
> "Greg" <garn...@notsohotmail.com> wrote in message
> news:10805500...@news.commspeed.net...
> > Here's a couple sites to check on prices....
> >
> > http://www.centralhobbies.com/Engines/ys/index.htm
> > http://tinyurl.com/28sah
> >
> > You might want to check with your LHS. Ours can normally beat these
> prices.
> >
> > Just out of curiosity, are you leaning towards the 1.4 Sport or 1.4 DZ?
> The
> > DZ will be replaced in May with the 1.6. We have 2 of the 1.4DZ's
running
> > now and they are VERY impressive! On a H9 100" Cub, it will hover
around
> > 1/3 throttle. No doubt expensive, but you get what you pay for.
>
> Thanks for the leads, Greg.
>
> I was interested in the Sport. (limited budget) Actually, I didn't
really
> feel the need for a 1.40 and would have been happy with a 1.20. Now, the
> 1.20 is a 1.40, soon to be a 1.60. Maybe the .91, now a 1.10, will soon
be
> a 1.20? =:-0
>
> Good flying,
> Bob Scott
Your welcome Bob.
A friend and I were having a similar conversation last weekend, wondering
where it was going to settle. It leaves a large gap between the 1.10 and
1.60, especially in the financial department so I'd guess they'll keep the
1.4 Sport to fill the void.
You're right about the changes at YS the past year or so. There's got to be
a ton of aluminum on the floor with all the case boring going on in that
plant. I know you were kidding about the .91 into a 1.20 (got a good
chuckle out of that one) but the 1.10 is probably the limit on that case.
Good luck on the quest. There's still 1.20's around so if you do look into
one, I'd go with the last version on the parts supply standpoint alone.
Greg
Elmshoot
>> Here's a couple sites to check on prices....
>>
>> http://www.centralhobbies.com/Engines/ys/index.htm
>> http://tinyurl.com/28sah
>>
>> You might want to check with your LHS. Ours can normally beat these
>prices.
I just picked up a case of Wildcat 20/20 for 17.95 gal from my LHS. I am glad
my LHS was there so that I could help them help me.
wingerit
you should use power master fuel or any other fuel specially formulates
for YS if you use something other that that you will have problems with
the regulator gumming up
--
wingerit
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yser
compression ratio is higher on air chambered engines (currently on the
1.15) compared to non-air chambered engines; comparing the YS 1.20AC vs
the 1.20SF. I'm not sure if this has anything to do with it. But I
think a non-air chambered engine would have a greater pressurized fuel
charge on intake than an AC engine (because of the volume of the AC). A
higher compression engine like the YS 1.15FZ would be prone to
detonation if it did not have the AC.
--
yser
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