After searching the forum, I think I have finally decided. Local hobby can't order it, cause Morris has no engines, (Crazy, huh?), well they have a 91. Might be a tad heavy. I am going to order the Morris knife (ARF, of course) myself and put on a Saito 56. (Jeeez, 4 strokes cost big $$!)
There is a Magic flying at thr field with a saito72, and it floats like a feather. Just made my TT extra w/OS61 look like a buick.
I figure a 56 will be lighter and powerful enough. Ms. Santa says I've been a good boy this year and it will be under the tree!
If this engine aint' gonna work, tell me quick! If not, I'll post back when it flies.
Tom

How about the Saito .72?
A little more in the money department but well worth it for the performance it will give that plane.

Keep in mine that the Morris ARF's dont generally come out light since they are sheeted with lite-ply instead of balsa...

The 56 will not have enough power to pull it out with authority of a hover. A friend is flying his with a Saito 65, and it just barely has enough to give unlimited vertical with the right prop. If you have to go with a stroker go definitely with the Saito 72 if not I would go with the OS50SX or Irvine 53. Less $$ then the strokers and much better response. You will still have some $$ left for a nice Ultrathrust muffler
Keep in mind that those are the engines of choice in the profile brotherhood. www.the******************.com

I don't know. I see messages where guys say a 56 is plenty of power. If it is enough to easily hover and climb out I thought I'd save the weight.
And, I just hung up from ordering the knife from morris! (Billy Hell, this is all your fault!)
Tom

well, Billy is flying his with a Irvine 53 ! The 2 strokes are the lightest of the bunch also ! Your Knife ARF will be at least 5 lbs (if not more). The Saito 56 will not be enough if you intend to do all the 3D maneuvers.

Saito 56 : 410 g
Saito 72 : 470 g
Irvine 53 : 400 g
OS 50SX : 390 g

The throttle response is much much better on a 2 stroke, which is needed when hovering for example.
I tried it myself and therefore am running a Saito 100 on my Showflyer. I regret it already for not using a 2 stroke. Don't get me wrong, it is a very good running and reliable engine, but doesn't respond as well as my 2 strokes.
Oh well, just my $0.02

Isnt it funny how everyone has differing views on this subject..
I use 4 cycles in my profiles for the throttle response, low end power, bigger props and reliability..

Bottom line. Use what you like.

Not trying to start a war.
But I have knife ARf.
I just think the 52 fourstroke is gonna have the power to pull out of a hover w/ authority.

Now if you decide to build the kit, well thats a differant story.

I have a knfie ARF w/ standard BB radio gear. 1100mh batt pack. ST45moosecan, weights 5lb 3oz.

I had a kit build knife, standard BB radio gear 1100mh pack, weight was 4.5lbs. That 11oz lighter than the ARF.

Do you mean it does or doesn't have the authority


I'll have to second Wayne by saying "Use what you like" ! If you feel more comfortable with a stroker then I wouldn't listen to us and buy what you like. You are the one who has to fly the Knife and not us !
Let's don't let this become a discussion again between 2 and 4 stroke engines ! There have been so many.

Exactly...........

I fly my Knife with a TT .54 four stroke and it was severely lacking power. Do yourself a favor and get the .72, the Ys 63, the Irvine .53 ($118), TT Pro 46, or the old stand by the OS 46 FX.

I recently finished my Knife ARF with an OS46SF. It came in at 5lb even with the CG at 5 inches back. I added the ultrathrust muffler and use an APC 12.25x3.75 prop and it hovers at 1/2 throttle. Go with the 2 stroke and spend the balance $ on fuel and have a blast. Pete

Sorry I had a typo,
I don't think a Saito 56 is going to pull it out of a hover very well.
I say do what you like.

Also if your gonna spend the money on the Saito56, poney up a few more dollars and by the 72. with the saito72 yo have more options for planes.

Its better to pay a little more upfront and have more power than needed. Then spend $170 and not have enough power then have to turn around and buy another motor.

I agree w/ Wayne on the 4 stroke thing. Its all what you get used to.

I had a YS63 on my topcap. Flew great. I was having motor problems and put on a ST45 w/ moosecan.. It still flew good. but it flew a lot better w/ the YS63 on front swinging a 14x4prop.

Some people like 2strokes, some like 4strokes. But is boils down to what you like.

Okay, okay! I bought a Saito 72 on the way home (what a dangerous place to put a hobby shop!) I ordered the knife (should be here Thurs.) We get off from Mon thru Jan 6, so I should have lots of time to get it together and try it out. I wanted to go light, but the 52 doesn't sound like enough and the 65 actually weighed more. So I splurged for the 72. - $213 vs $173 for a 52 and $183 for 65)
I always wanted to try a four stroke, I love that sound. I watched that guy with his Magic and 72 and it just went click. I figure spend a little more if it is going to be a necessary performance advantage. (Got a 13x6 prop.)
Actually, my fiancee is buying me all this for Christmas! (And she already thought I had too many planes!)
Oh, she got me a Profile Brotherhood shirt, too! (Okay, I ordered it.)
Life is good!
Tom

There you go ! Now you have enough power to rock the sky.
I just wish my wife would buy me airplanes or airplane stuff for x-mas. Oh well, I guess I'll have to keep hiding the receipts from the Hobby Stores.
Life is still perrrfect

onrecess
Make sure you use an OS #F plug or your doomed to fustration . The 72 is the best choice , you should soon have a big smile on your face .
Maj. Crash

i agree w/ Mj.Crash, as soon as you take the Saito out of the box, take out the plug, and throw it as far as you can see. then put in an OS "F" plug.

there was a guy at my field w/ a pretty new Saito. He has a couple of flights on it. an he wasn't happy. He told me his needles were off. I asked him what plug he was using. he said the one that came w/ the motor. I told him to take it out and put in the OS "F" plug. he said it wouldn't run any better on an $8.00 plug. So i offered to let him have a new 1 of mine and try it. And if he liked it he can buy it. or if he didn't like it he could give it back. Needless to say, he bought my OS "F" plug.

Cool, I will. The guy told me to pull off the valve covers and drop in auto trans fluid, he said they ship dry. Is that right? Can't I just prime it?
Tom

I heard THAT! Good choice, I think you will be very happy that you splurged.

You wont be sorry.....

I use the supplied plug for break in. You have to run the motor so rich anyway for the first several tanks that your gonna mess the plug up anyway.
Break it in on the one that comes with it then get the "F" for when you start tweaking the needles..

what plug comes in the 72 mine has 5 gallons threw it and the factory plug , i never even thought about it.

you won't be dipleased with the saito 72 , best 4 stroke ever built. break it in right and i think they will run forever
Chad

The Saito 72 is the Chevy 350 of the RC world. I sent all the ProBro shirts to Morris and have been watching the site to see when they would sell them. What part of the site did you order it off of? I didn't see it.