Hi Venus 2 pilots !

I have an OS91fx (going to be ordering an untra thrust muffler for it) and am wondering what type of prop I should be running ?
13 x 6, 8 ??

Thanks,

Ziomarco

Hobbico reccomends 13x8, 13x9

I am using a 13x9 on a Lttle Tni right now and not sure i'm happy with that.

the manual calls for 14x8~10.

with a 14x10 APC I got 8500 rpm, a bit on the low side for that engine.

If i were doing it for the Venus i would start with 14x8 myself.

Clearance is not problem with a 14 inch prop as I am using a 15x10 on my Venus with no problems at all. (os ax120)

I just bought Venus II ARF from GP and I have a few questions:
I'm going to use O.S 120AX with a stock muffler, what prop should I use? 15x10? 16x8?
Where is the recommended CG point?
For elevator control, are you using two servos or just one? I'm afraid it won't balance well with two servos in the back.
Should I use the links that came with the kit?

Prop: I am using a OS 120 AX on the Venus with a 15x10 prop and it's perfect.

Muffler: What angle are you mounting your engine?
I reccomend horizontally. If you do you will be much better using the Bisson muffler:
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXMKK3&P=Z]Bisson 1.20 AX Pitts Muffler[/link]
If you are mounting engine angled then the stock muffler will work

CG should be right where great planes calls for 6 1/2 inches back from the flat part of wing leading edge.
That is the center section of the leading edge. Venus is a swept wing so be sure you are measuring from the center section.

Elevator servos: Use two elevator servos mounted in the back. The Venus balances perfectly without any added weight with a 120 AX up front if you mount 3 servos in the back (2 elevator and 1 rudder). Use the RX battery to fine tune the balance. I have not had to add lead weights to any of the 4 venus's that i have built.

Links: I use the supplied links for elevator and rudder. For the ailerons I use clevis at the horn and Dubro swivel ball link at the servo
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXD906&P=7]Dubro Swivel Ball Link2-56/4-40 rod[/link]

See my earlier posts for pictures of all of these items.
Also the Venus flys finer with the tank mounted over the CG, but either way should be good. With the servos in the back there is plenty room for the tank over the CG. It's your choice. I posted info on how to do this as well.

I have used the 17X6 APC and that gives great thrust..... Good for 3-d...... I am not sure how that would work on a pattern set up though....
Codfish,
Have you tried other props, and how did they work??

Justin

I have only used the 15x10 prop. I max out at about 9,000 RPM. It has given me such good performance i have not wanted to switch.
It's a master airscrew. I know an APC would give me a bit more thrust, but the master air scew weighs about 1 oz less, gives me all the thrust i could want and the balance is perfect. On takoff i can immediatly pull strait up and continue verticle untill i chicken out becasue the Venus becomes a small dot in the sky directly overhead.

If you decide to try another prop I would be very interested to hear how it works out for you. Let me know!

After the first season with this engine I can now get 2000 RPM totally reliable idle (the lowest idle i have ever got with a glow engine.) It never quits or dead sticks.

HAs anyone ever used a OS 120AX in a Venus II?

I have a YS110 in mine but it now has to go back for repair a 2nd time after less than 8 flights [:@] so I was going to swap it out for the 120AX I have in another plane.

Prediction........You will be glad you switched.
Treat your OS 1.20 right and you will love it.
Regards
JC

Friend of mine has an OS 120 AX in his and it flies very well. I have a YS 110 in mine and couldn't be happier with the way the YS has run so far.

There are many flyers that have an OS 120 AX in their Venus II. Just look back over the last 6 posts!
I have put an OS 120 AX in 4 venus's now at this point.

If you look back through this thread you will find pictures I have posted with the 120 AX installed, check them out at this link (2/3 down the page):
[link=http://www.rcuniverse.com/forum/m_3993257/mpage_27/key_/tm.htm]Venus II with OS 120 AX installed[/link]

This is the most relaible combination I have ever experienced in any RC plane (Venus II with OS 120 AX)

Mine has YS110 and the tank is right at the CG. This CG never changes during the flight which is great thing to have.

Have the YS110 for 2 years and never have an issue with it.

Yes I think we can all agree that YS , O.S are Fine running engines...!!!!!!!

All manufactures can have lemmons....... Unfortionately when YS engines have to go back for warrenty, it is ussually operator error that has caused it....
O.S. is more of a non-putsy engine.... Very simple to use and you have to work hard to screw it up....

Just put a YS 110S in my Venus replacing the OS 120 it was originally powered with. No issues with the OS, I just prefer YS'.

I moved the tank back to the CG and thanks to it's lower weight, removed the 2 oz. of lead needed in the tail to balance out the heavier OS engine. I haven't flown it yet though I did run it on a saftey stand. This thing is a BEAST!

I'll post pictures of the install later.

Sounds good. What prop are you using with the YS, by the way?

Pappy,

I had thought of trying a YS 140 sport in a Venus II.
Do you think that would be too much power?
Anybody have a sense what size 2 cycle would be equivelent to a YS 140 sport?

Yeah. That would be rediculous. I flew it three times today after struggling to get it running reliably (the engine's fine, I'm stupid - should have read Troy Newman's tuning instructions here BEFORE running it not after!!!).

There's only one word to describe the power of a poorly tuned YS110 in a Venus II - BEAST!!! I'm actually scared to find out how it runs when I tune it properly!!! Serioulsy, the 140 would be WAY overkill. With the 110, stock muffler, and three HITEC 5645M's in the tail, it balanced perfectly, right on 6.5", runs for over 12 minutes slobering rich on 16oz. fuel, and only weighs 8lbs 7.5oz.

Al Torres

Be careful not to lean out the YS110 too much as you run the risk of blowing the seals and its NOT covered under warranty!!

YS110 has prenty of power as the wing profile on VII is pretty thin. It could be a different story if a different plane (e.g., the showtime 3D 90).

I hit full throtle only in up lines. With 15X8 prop, it flies pretty fast.

YS140 is definitely an overkill. Besides, the firewall may not be strong enough.

If you already have the 1.40 and the plane I say,,, Go for it.....

You would have no issues with weight and just keep an eye on the structure of the airframe.....

That engine powers a 73" inch 11lb yak 54 with authority.... so be carefull with your throttle..

Watch out the prop clearance as well. 15" prop seems the largest that VII can take.

Not to mention throwing the prop and the spinner, along with the pre detonation that ruins the thrust washer. ( don't askme how I know )
If you hear a high pitched tinging noise it's too lean !!
Just follow Troy's instructions and then leave it alone once it's set!!
Eddie

agree.

A simple way to avoid lean run is never set the needle NO less than 1.25 turns out.

Nonstop that is pretty good advice but it doesn't work for everybody.

Needle valve settings will very a ton depending fuel, temp, elevation and so on.

I was in Alb New Mexico a few weeks ago and my HS needle on the 170DZ (glow) was at 7/8ths and it was actually a bit too rich. Albuquerque is about 5000ft elevation.

I also ran the Focus Sport out there and it has the YS 110S on it. It ran about 1-1/8th open.

We were running 30% Cool Power Heli fuel. If a guy was only running 15% nitro the needle would need to be set even leaner yet. There are just way way too many variables.
If you travel to high elevations you will be amazed that you have to dial in the HS needle say 1/2 turn or more from Muncie to Denver. Not sure you conditions in TX...but try going to the Lubbock contest when Ed Deaver gets back on his feet. You will learn what tuning a engine at High elevation is like. I think Lubbock is about 4k to 5k.

So you can't use a blanket setting that is too lean. It just doesn't work. Peak it slowly a click or two at a time, and back it off 300rpm. This is the proper way to set the HS needle.

instructions are here

www.patternflyer.com/troy

Troy Newman

Troy,

Others may set HS needle less than 1.25 turns out. But with my YS110, it is simply will not tolerate it. In one occasion, it throwed the prop out as sonn as the throttle reached full for 3 seconds. Luckly nobody was at front! The fuel used was YS20/20. If this can happen to my copy, it can happen to others and hence my post.

Talking about a piece of general advice, I would think that never set a lean setting on YS110 is a good one. That is the bottom line of last few posts, right?

Regards

Like I said your conditions, your engine and your fuel....yes that may be your limit.

its just a number of turns can't be specified to apply to all conditions. In fact if you take that same engine to high elevation it will likely be so rich that it won't hardly even run. So a blanket statement of numbers of turns just doesn't work. Its not that others can set their engines leaner...its just a fact that too many variables can play a role. The "too Lean" setting will be different depending on the conditions and the individual engine...These things are high tuned precision motors. Yes you should not run them lean. Any 4 stroke regardless of manufacturer will do this if you get it too lean.

For this very reason you should always use a double jam nut prop nut to prevent the prop from coming off it it backfires like you describe. If you use a double jam nut type this throwing the prop doesn't happen. Yes it will throw it loose but the prop doesn't come off. All YS 4 stroke engines always come with a double jam nut assembly. If you need one the Tru-turn 0814 is the one I use.

If you follow my suggestions on setting the engine by slowly finding the peak and backing it off 300rpm it will not be too lean.

Troy Newman
Team YS