I have an OS 120 FS in my Venus II. No you do not need to do anything to the firewall. You could use the mount that comes with the plane but I choose to use a Dubro 686 only because this is the mount I have been using for years with good luck. It shows the 120 mounted at an angle in the manual but I choose to mount mine fully inverted. This meant doing some surgery to lower the fuel tank and adding some exhaust pieces. All in all I am very happy and glad I went the extra mile to fully invert my engine, they look like C#@* hanging out the side, I posted some pics of my install earlier in the thread but here they are again.

If you wish to add the exhaust manifold & flex pipe they are available at Towers and I can give you the part #'s if you wish. Did you give up on the .91 ????

P.S. If you choose to invert it you almost have to install some kind of external connection for the glow driver or keep reaching under the plane to connect / disconnect the glow driver. This is a pain in the A#@ and very dangerous. There are several different kinds and are cheap.

At this point I'm not sure what engine I will use. Yes, the OS 120 4 stroke would be my choice but those are $319.98 compared to a NIB OS 91 surpass I have right here. Me, being more of a sport flyer, maybe I'll just try the 91 4-stroke and see how it pulls the venus around. I can always change it later.

charlie

As I said keep it light and I think you'll be alright. Will it have the vertical of the 120 - NO - but it will be close.

If it's the vertical that people are looking for using the 120 4 stroke I just might use the 91
4 stroke after all. I'm not into verticals, they make my neck sore. I got out of rockets a long time ago.

After 80 feet I stop watching other people do their verticals. Where they planning on landing? The moon?

I appreciate all the comments though.

When tower stopped accepting food stamps, I cancelled my order on the OS 120 4 stroke.

"hungryandbroke"

I don't really mean outa site verticals. I'm talkiing about flying this bird the way it was meant to be flown. Point rolls on the way up, humpty bumps, vertical snaps, etc., etc. You can't do these cleanly without power, my 120 struggles on a few. If I had to do it again I would go YS 110 or even a 140.

Good luck !

Ditto, I've got an O.S. .91 Surpass, and I knew right off the bat it wouldn't get the job done. Excellent vertical with a 6.5-lb airplane (Fliton Extra), but not on an 8.5-lb airplane. Big difference![:-]

Well, actually, this is my first pattern plane and I don't expect to be in any contests now or ever. I just liked the looks of the plane and all I wanna do is some knife edges, rolls, and whatever.

I just want an engine to get me airborne and at least hold a knife edge. I'd be pretty upset if I paid $320 for the OS 120 surpass and found out it doesn't actually run (with no problems) like my OS 91 surpasses do!

I'm sure the 120 would pull it better but I'm not entering into the world championships!

Maybe I should do a poll on the OS 120S-E surpass w/o pump and see if others have any problems with that engine.

charlie

I have a gaggle of YS's, a gaggle of Saito's and 1 OS, the 120. The YS's have the edge in power, the Saito's have the edge in weight but the OS 120 is flat out the most realiable and carefree of them all.

Anyway one of the best things about this hobby is that everyone is different and are free to do whatever they darn well please. I know I rarely listen to anyone else. Just ask my wife

Well, if you like knife edges, you're going to like it. It will do a knife edge loop, but I've got a long way to go to clean it up and make it round -- the second and fourth quarters of it are still quite ugly.

Nonetheless, fantastic knife edge characteristics. I have no mixes on mine and there is zero coupling for elevator and aileron. Very clean rolls, and very stable in the air. Stays right where you put her. Stall turns rotate on a dime and give you change. I did mix in a tiny bit of down elevator for low throttle downlines because it pulled to the canopy slightly. Hey, wings gotta have a little incidence.

Yep you can still have a lot of fun with it with a .91, but it just flies so doggone well that it begs for a bigger engine to extract more of its potential.

in reply to russell bear,how does the fuel effect the bounce on landing?

Good question, but I thought he meant Inspector Clouseau's "fuel" (fool) who was manning the transmitter sticks.

If that's not it, I'd be really interested to know how fuel makes an airplane bounce.

Was waiting on someone to catch that one. The problem was that I needed to burn more of it. The landings are right on the spot now.

i think thats my problem too. was it because it was too fast,too slow or what. every time i come in it's a 3 point followed bye a big bounce and then a few little ones. i've tried releasing the elevator at touchdown and i think that makes it worst.i have a hard time pushing that right stick so close to the ground.

The first few times there was zero wind and I was landing pretty hot, tried slower to the point of stalling it and it was bad then too. I guess it is just releasing the sticks at the exact time when the wheels touch that make it not bounce. So far so good.

It will also help to fine-tune your CG. Perfect is when flying inverted it takes just a touch of push to fly level, which for my Venus is around 6-3/4". If you typically land with about 30% of your fuel remaining, then you might want to balance it with that much fuel in the tank. This will guarantee the most optimal angle of attack when landing.

If you haven't tried the spoilerons yet, do so. They will make you a believer.

On that, I set mine up more like flaps, they move down with the switch. Should they move up instead for spoilerons?

Yes, they should move up for spoilerons. Start with about 3/4" up and maybe go up a little from there. Makes the final approach less floaty and the landing stick. But if you need to go around, still plenty of elevator and aileron control to take off and set up again, and just to see how the plane flies you can fly around easily with the spoilerons deployed and observe the stall characteristics up high.

You may need to mix in a little down elevator. Seems a bit counterintuitive at first, but you will see the nose pitch up a smidge with spoilerons...

Thanks, I'll give it a try...

Ok, Ok, Ok!

This is for all you professional (or wanna be) pattern flyers that are using the OS 120 2-stroke on the Venus ll.

I'd like to have these questions answered since I am just a sport flyer and never mounted any servos in the rear.

If I used the OS 120 2-stroke I need all the recomendations I can get! And all I have to use is a Futaba 4 channel YF with no low or high rates that came with standard 3004 servos.

Muffler or extentions, servo sizes and placements, tank size, and whatever tips I can get to get this silly thing in the air before I send it back to tower and order something that calls for nothing more than an .049 !!!

Please help!

charlie

Man your making this whole experience really hard on yourself.

#1 - this is not a "silly" plane. If you feel that way send it back.

#2 - the 120 2 - stroke would be an ideal engine for this plane - but then the .91 4 - stroke you talked about would be fine also.

#3 - I do not believe standand servos would be any good for this plane ( MAYBE on 6 volts ) except on the elev. and then only if you used 2.

#4 - IMHO opinion if you are not ready to up grade some of your equipment I would look at another plane, maybe the .40 size Venus.


P.S. If you already have the kit most of your questioned should be answered in the manual.

If I knew the OS 91 4-stroke would fly it alright for a sports flyer, that's what I would want to go with. I'm not a spead deamer and I'm not entering it into any contests. Just want to do some "silly" knife edges and maybe roll it around a bit! The 91 weighs a lot less than those larger engines!

I have a goldberg tiger 60 with 6 oz's of weight under the nose to balance it out and my OS 91 surpass 4 stroke pulls that thing around with no problem! I'll bet it weight 8 to 8 1/2 lbs.

"confused charlie"

but i'm not ruling out other engines just yet.....

Don, I am using standard (3001's) on everything except the rudder, where I'm using a 3050 digital just because I had it. I think the analog 3010 would have enough torque as well for the rudder. But I am running 6 volts (Lipo and a regulator), so I am able to use the full practical servo range (EPA's at 115%) for good resolution and still have adequate speed and better centering.

Charlie, it is possible to set this plane up with a 4 channel radio, but setting up dual elevator servos is going to be a challenge, so you might want to use one elevator servo with a split pushrod. In that case I think you could get away with a 3004 on each aileron, but you would definitely need two 3010's, one for the rudder and one for the elevator. If you use one 3004 for both elevator halves, or a 3004 on the rudder, your Venus will not be around for long. Figure out the balance by installing the engine, cowl, prop, spinner, throttle servo, fuel tank and landing gear first, then temporarily secure the receiver and battery with Velcro and lay the elevator and rudder servos on the horizontal stab to get a ballpark estimate. With the O.S. 1.20 4S (30.5 oz with muffler!), I mounted 3 servos in the tail and have the receiver and battery far back (I added a little battery shelf at the fuse former near the wing bolt receivers), yet still had to add 2 oz of lead to the tail to get the CG where I wanted it. The 1.20 AX w/muffler is not much lighter (29.9 oz) than the 4-stroker so you might expect a similar set-up.

I had a half a notion to send it back and just go with the little "puddle jumper" venus 40......but I'm not! I'm going BIG!

I'm keeping my Venus ll, buying a better radio than the standard futaba 4 YF I have now, better servos, larger engine, and whatever! If you're gonna do it, do it right! right?

But, I'm on a limited budget!

And after I read all the recomendations for what I need for me to do this I'll enter my Big Bad Venus ll into the "expert" pattern class! (They give out larger trophies than the beginner catagory and I ain't settling for 2nd place!)

I'll see ya all at the next contest!

Move over! Ole Charlie is ready for some real action!

Atta Boy Charlie. You go get 'em

I can fly these "goofy" planes better than some in here think!

I love flying a knife edge with my astro hog with an os 91 surpass on it full bore 5 feet off the ground. Or get it up high and put it into a spin and pull out about 10 feet from the ground! Yeah Baby! A real crowd pleaser!

Just the other day a guy was flying his great planes 300 which was nose heavy with a super tigre 75 on it about 100 feet off the ground full bore and the elevator stopped working. He said, "Here take it! I don't have any elevator!"

I took over and yep! NO Elevator! No problem!.......who landed the plane smoothe as ice?

"Charlie"

Remember......charlie won't settle for 2nd place! lol