tuwood

I am purchasing an OMP 48" Katana V2 46 ARF and was wondering what you guys would recommend for an engine & why.

What kind of RPM numbers are you guys getting on each?

**edit**
OK, I just added Saito 82 because several are recommending it.

Maudib

My Feedback: (51)

For an oz and a few $$$ more you can get the Saito 82 that is the same weight as the 63...

I've used the 72 on several aircraft and absolutely love it... both engines will prefer higher Nitro... the YS likes 20% and the Saito really shines on 30% Heli fuel.. purring like a kitten and idling awesome from the very first start.

I haven't had the best of luck with YS engines int he past... being finicky for me... I've even sent them in for "tuning" and paid good money to do it... only to have them come back throwing props...

I'm not baching them as lots ogf guys have great success with them... but for me a Saito 72/82 on 30% is a "lean to top end rpm and back off a couple clicks" and forget it engine.

Any of these engine will rock your profile...

drdrain

YS engines are capable of high rpm's per the cu. inch size. but, on the downside, they are unreliable (at best), on most days? unstartable. they are very picky about the kind of fuel they like and the wrong kind of fuel can actually damage them.

the real comparison is power to weight ratio. saito wins hands down against all competitors if you ignore the "cubic inch comparison" game and simply compare power to weight ratios. and saito is absolutely reliable. the first time, every time. and yes, the saito 82 is the way to go. more power for the same weight.

seanychen

My Feedback: (4)

Were those your YS, or just hearsay? The last YS that gave me trouble was in 1992 when it just came out. Every YS's I've own since 2000 has been dead reliable, more so than my Saitos I might add. I have YS 110, 120 NC, 140 DZ, Saito 72, 82, 91, 100, 180, and 220. I sold my Saito 82 because its excessive vibration was causing turbulent fuel tank on my profile Katana 46, leading to lean run. I am one of the best glow engine tuners in my club of over 100 members, and I sometime have problems with my own Saitos (72, & 82), as well as YS's (but only on the 110 because of the wrong diaphram screw setting).

I have this many Saitos only because YS don't make them in those sizes. I can personally attest that YS 4-strokes nowadays are not finicky to tune, once you know the proper setting. Some Saitos on the other hand have me chasing the 2 needles back and forth.

I haven't owned the YS 63, maybe it's the problematic one. For your Katana profile, I would recommend away from Saito 82 because of my exact vibration experience with identical setup. Saito 72 is more than enough thrust for that 4.25 lb. bird, and won't have the vibration induced fuel draw problem. It will swing APC 13x4W @ 11000 rpm, tested at 8 lb. static thrust, which is perfect. YS 63-s will get another 1000 rpm on this prop and pull about 9 lb. You really don't need another pound of thrust once you get 1.88:1 thrust to weight ratio.

tuwood

I've been digging around RCU & see some are saying the 82 vibrates too much for a profile. Any thoughts on that?
I have a Saito 1.25 & it vibrated a lot until I leaned it out.

tuwood

Thanks seanychen this is the kind of stuff I'm looking for. I have heard of YS's being problematic, but I also wonder it they used to be problematic but continue to have that reputation unjustly. I've never owned one, and I've only owned one Saito so I don't know much.

Richard L.

My Feedback: (24)

I've been running YS engines for the past three years and all of them purr like kittens, so I don't know what you are talking about. Check out my website for videos of YS engines in action. Do you see them hiccup? Below is a picture of my new YS 63S breaking in on the bench with a little more than half a tank of fuel through. Please do not spread unsubstantiated rumors. The wrong kind of fuel can damage them? Please. They can be run on any 15% or 20% fuel with or without castor oil.

djlyon

Well I have both those engines and have flown both in the exact same plane, a Pizazz, with the same prop and fuel. The YS63 turned a 13/6 APC on 15% powermaster about 300 to 400 RPM more than the Saito 72. In the air on the Pizazz I couldn't tell the difference between the 2 engines. I would go with the YS because it is prettier and that counts.

Denis

tuwood

Thanks for all the good discussion guys. I was somewhat concerned about the YS because of all the negative things to be found on RCU, but after reading your comments I have a feeling that they're not quite as bad as one might think. There were a bunch of pattern guys at my field on Sunday & guess what all of them were running? YS and they all loved them
So I went ahead and ordered the OMP Katana combo with the YS 63.

I should hopefully have the engine by the end of the week. I'll put it on my test stand & let you guys know what I think. I only have one Saito & 2 OS 46's so I'm not an engine expert by any means so if I can get it running & tuned in good then anybody can.

Zombie

tuwood,

I have 2 of the YS .63S engines - one is currently on a Katana V2. They both purr like kittens - and roar like tigers when I hammer the throttle. Never have had a dead stick or hiccup with either of them.

Both only had enough bench run break-in to insure I had a good/reliable low idle - which took a half a tank of fuel. Then I put them in the air and flew them. I don't believe in many-tanks-on-the-bench break-in. I break 'em in like I plan to fly them.

Transition slowed on both of them at about the 1 and 3 gallon mark. A slight tweak (1/4 to 3/8 turn in) on the regulator screw sweetened them right back up.

Before you install the engine, go over all the bolts and make sure they are tight. Most of mine needed a small, partial turn for snug.

Be sure and use a good fuel filter. It only takes a small spec of crude to mess up the diaphram in the regulator.

Be sure you have a bullet proof fuel system. The engine develops a lot of pressure in the tank - and the engine needs the pressure. So make everything tight and leak free. The check valve is a must. Be sure and install it in the proper direction. When you refuel, be sure and open the vent/pressure side line first or you'll get a fuel bath.

Don't use castor. It'll eventually gum up the regulator. And yes I know some guys like to run 10 and/or 15% fuel - but I've never understood why one would buy a performance engine and then skimp a few bucks on the fuel it needs to run at its best. Use YS 20/20 fuel and your engine will perform the way it was designed to. It'll keep it really clean inside also.

I recently had a radio hit on a Katana GS at takeoff. The plane nosed almost straight in, into the asphalt runway, from about 20 feet. Bent the crank shaft on one of my .63s. When I dis-assembled it I was amazed at how clean and shiny the inside was - even though the engine has 10 or 11 gallons of fuel through it. There was no build-up of any kind ... anywhere. None of the typical build up that I've come to expect when I open a castor fed 2-stroke. Gobs it was pretty inside! Just like new. There'll be nothing but YS 20/20 fed to my YS engines. The engine is all back together again with a new crank and front bearing. Runs wonderfully. Just like before.

Remember that the low-end screw works the reverse of most other engines. Clockwise is richer. Other than maybe checking to see where it's set at, by counting the clockwise turns to gently seat it, try using the factory low-end setting for your initial start up.

Here's one of the better tuning sheets for the YS engines. You might consider printing it and putting it in your field box.

[link=http://ysperformance.com/html/instructions.htm]YS Engines General Instructions[/link]

I like the APC 13 x 4 Wide on the .63 equipped Katana.

Maudib

My Feedback: (51)

A most excellent post Zombie! Thanks for taking the time to be so thorough... maybe I will have ne another go at a YS...

tuwood

Once again, thanks everyone for your help. My YS 63 showed up Friday & I finally fired it up on the test stand today.
I have limited 4 stroke experience & only have a Saito 1.25 to compare it to and well, it was every bit as easy to start & run's perfect.

Setup:
30% Coolpower Heli mix
APC 13x4W

I started at 2-1/2 turns out on the high side & left the low speed stock. It fired right up & purred like a kitten straight up. It transitioned real well even at this very rich state. The directions were a little vague on break in other than run it very rich for 20 minutes so I did the somewhat Saito esque break in by keeping it under 4500 RPM for the first 10 minutes & then short bursts of medium to full throttle for another 10 minutes (20 minutes total). Then I leaned the top end about a half a turn (2 turns out) & the RPM's got up to around 11,200 with lots of white smoke. It idled perfectly at 2200 RPM and transitions were smooth as silk. She's ready to go fly!
I'll leave it at 2 turns out until several flights & gradually lean it out for peak. Judging by the amount of smoke it's billowing I think there's quite a few RPM's still hiding in there.

So, in comparison to my Saito it actually went a little better because I did have to tweak the low end on my Saito quite a bit to get a good low idle, but both engines were extremely easy to set up & run great.

Thanks

Richard L.

My Feedback: (24)

Based on my past experience, I found tuning the low end on YS engines (even inverted) much easier than tuning the low end on Saito's. I have spent countless hours at the field trying to get inverted Saito's to idle reliably. Remember that to lean out the low end on the YS, you have to open the idle screw counter clockwise.

seanychen

My Feedback: (4)

Inverted Saitos do take a while to find the sweet spot. A bit too rich on the idle and it will load up and unable to maintain prolonged low idle; a bit too rich too lean it will quit when you juggle throttle quickly. We are talking margin of +/- 45 deg... not a lot of room for error.[&:]

JohnW

My Feedback: (6)

Tony, I'm sure you'll be happy with your decision to run a YS. Mine run super great. Flew for the first time since October two weekends ago. All three planes I flew, each with a YS (63FZ,110FZ,160DZ) instantly started at idle and ran like a beast in the air, even after sitting for six months. Running the same mixture setting from when I originally tuned the engine. No messing around… just start and fly.

Once you get used to the power and consistency of a YS, it's hard to pick any other 4-stroke. I ended up selling all my non-YS engines, they just pale in comparison. Yer right, just look at pattern flyers (myself included). We need power, consistent runs, good throttle response and reliable engines (not that any of that actually has helped my scores, but it is hard to score anything with a dead engine.) If we use a 4-stroke, it is aYS, and for a reason.

They aren't hard to set, but they are different than other engines due to the regulator. Yours should run pretty well by just tweaking the high/low needles. However, I have found that at our typical summer density altitude, the midrange sometimes goes a little fat, which requires like a 1/4 turn on the regulator to fix. If you do run into a tuning issue, I'd be more than happy to help, not far away. You can also contact the Omaha pattern folk, I'd suggest Claude or Ron, either could probably help if you should need it.

tuwood

Thanks John,
I do have one question about the regulator. Obviously I'm not going to touch it unless I need to, but what does adjusting it do? Does it just allow more fuel flow, or does it alter the pressure in the tank. The manual doesn't really say anything about it other than to leave it alone.

I need to get down to Lincoln one of these days. I live near Gretna, so it's not much further to lincoln than it is to get to Hawk field or Buds field.

Ladyflyer

My Feedback: (2)

Amazing what you gain by having an open mind. Most of the negatives are parroted by people with no PERSONAL experience with YS. The YS engines are different but very easy to operate. The throtlle transition is second to no other. Also bear in mind that the tank placement is not fussy at all. Locate the tank as close as possible to the CG and you can enjoy flights from start to finish without CG shift from the fuel burn. There is a learning curve to the YS , for those with a little mechanical ability it is no big deal. Congratulations for the excellent choice.

JohnW

My Feedback: (6)

Yes, don't change the regulator unless you need to. Always set low/high needles first. The regulator adjusts the duration of the fuel pulse to the needles/injector, i.e. basically it works just like one would think. Changing the reg is done mainly to fix midrange mixture issues, but since it will affect your other needles too, it is generally best to not mess with it unless you clearly have a midrange issue or cannot set high/low needles for some reason. Generally the regs are spot on or very close as set from the factory. However, depending upon fuel, prop, altitude, I believe they can be slightly off the ideal setting. I've never seen one factory set so far off that the engine wouldn't run. However, I've run into the situation where I am too fat (too rich) in the mid range, blowing way to much smoke, and response a little sluggish from mid throttle. A very slight tweak on the regulator, then resetting high/low needles due to the change in the regulator, seems to resolve. Nice bit is, as long as you don't change fuel/prop, once set, you will never need to touch it again. However, I wouldn't even worry about trying to figure out if the engine's midrange needs to be tweaked until you have at least a gallon thru it. If it seems strong, and responds well from midrange, it's fine. I honestly can't remember if I had to tweak the reg on my 63, but I know I had to on the 110FZ and 140L.

tuwood

Thanks for the info John!

I was able to take the Kat up over lunch today. Wow, what a sweet flying plane!!
The YS did great & seemed to hover it at a little over 1/4 throttle. I say seemed because I had it a few mistakes high & it's hard to tell if it's climbing or dropping.
Full throttle was pretty much un-necessary except for when I wanted to get a big smile on my face going straight up!
This is my first true 3D plane & I swear it's like flying a foamy the way it floats around & pulls out of a hover.

After the second flight I notice the idle had dropped a few hundred RPM's and was getting rough so I'm guessing it's part of the normal break in and I'll have to lean out the low end a touch to speed it back up. I had to get back to work so I couldn't adjust it at the field.
I'll play with it tonight.

So far, so good... I'm glad I picked the YS so far.

JohnW

My Feedback: (6)

Yes, the RPM change during the first gallon is normal. Every YS I've had required some minor adjustments as the engine brakes in. The power and response is nice... isn't it?