Since the OS 46fx engine on my NexStar has been *issing me off, I decided it was time to step up and order my second airplane while troubleshooting the engine gremiln. After much research, I decided on a Big Stik 60! Just ordered it up from Tower Hobbies and should be here next week in time for the long holiday weekend over July 4th. Can't wait to get it.

Now, I need to buy an engine. I've now decided that though OS engines are nice, they aren't immune to their own issues. I'm thinking something in a 90 sized two stroke. I've heard lots of good reviews of SK engines and their .91 is only $108 shipped, which seems like a steal. Anyone think this would be a good match for my new STIK? I also looked at a ST G90, but I heard there can be carb problems and lots of tuning issues. Any other recommendations for engine brand and size? I live at a higher altitude and was thinking an engine larger than a .60 would be ideal.</p>

I read what you posted, however, I have a pair of OS .75 AX engines and they perform better than anything I've had in that engine range. Good starting, outstanding power, and great reliability. They have the power of a larger engine.

CGr

Iuse the SK .91s and love them. Ed Moorman in RC Report got me into them after he wrote an artical about them. Istill have his report and how to break them in. There was also a mistake in the instructions reguarding the prop size for this engine, anything smaller then about a 15X6 tends to make them run lean. Ihave used both the Brison Pitts muffler and now I'm using the stock muffler and there were no pressure problems at all with either one. To date Ihave never had a dead stick with mine!!
So far Ihave run them in 60 size pattern planes and a heavy 60 size Extra 260 and they pull like a tractor. Whenever Ineed another engine for a 60 size plane I just give Kangke SuperKraft a call, as much as I like OS Ilike SK better!!

Ihad a Big Stik 60. Ipowered it witha Thunder Tiger 91 4 stroke. I had a 15X6 prop on it. Ihad to mount 5 1/2"tires to swing the
15 in prop. It flew very well with the Thunder Tiger on it until the exhaust pipe broke. Itook the TTengine off and mounted YS91-FZ.
To keep the engine under control Iput a15X8 propon the YS.It would take off at half throttle and cruise around a couple clicks above
idle. Sadly, it met an unfortunate end this past January.

Ihave a Pulse XT60 thathas a OS91 AXmounted in it. The OSengine run perfectly untilIfed it some bad fuel and stalled. Itried to
doa dead stick landing. Ioverflew the runway and ran into a very large green tractor with a grater behind it. Sadly the rightwing broke in
half and the fuse broke behind theradio tray. The fuse has been repaired and the right wing is being repaired.

Ihave a test stand that Imount my engines in to get them into tune prior to mounting them into planes. It help the engine issues while at the flying feild.

James in CO

<span style="font-size: larger;"><span style="font-family: Comic Sans MS;">I think for relaxed flying the TT91 4C is nice, its a good engine. But if you want to invest in a nice engine then look at the Saito 100 for this baby. I did help a friend run in the new OS 110 ... oh man ... that baby is sooooooo sweet! Nice exhaust tone and the mechanical sound is not rough. That OS really made me think of going back to 4C engines.</span></span>

I'll ditto what CGR said. The new OS 75AX is a WINNER!!!!

I'll second the Saito 100, I have a Saito 82 on
my 40 size Stik and love it.


Bob

Didn't Saito drop the 100 and bring out the 1.15?? I don't know for sure but I no longer see it advertised but I do see the bigger engine.

Resist the urge to overpower your plane. Bigger engines weigh more, which adds stress to your airframe and increases your wing loading. A ball bearing .60-.70 engine propped right and tuned well will put the plane around just fine, and it will fly better without the added weight. If you feel the need for more power, you can go up to a higher nitro content in your fuel.

The 1.00 is still showing "in stock" at Horizon http://www.horizonhobby.com/Products...ProdID=SAIE100

It is $330. It may be worth it, probably is. But, if the original poster is looking at engines in the $100 range, getting an expensive four stroke might not be n option.

I prefer four strokes myself but have found the SKs such outstanding engines and for only a hundred bucks for the .91 you can buy three or four of them for the price of a four stroke. Such good running engines with so much torque.

I fly a big stik 60, it is my favorite plane, I am running a super tigre .75 on it and it is more then the plane needs by far. These planes have a huge control surface on the ailerons and are not made for speed. They have a tendency to flutter the ailerons. I can easily tool around at 70+ mph and have unlimited vertical with the .75 running a 13x7 prop.

I truly mean unlimited vertical, with the setup that I am using and some extremely high rates I can flat spin fat enough to climb. In my opinion a .91 2 stroke will just tear up your plane. Get a .75 and enjoy one of the best flying planes out there for a long time.

Just my opinion.

Since I live at an altitude of 5800 feet, I decided to go with the SK .91. Ordered it up from kangke today. I'm hopeful this will perform like PhoenixAngel's ST.75

OS AX 75, Fults 5 inch dual strut nose gear, Top Flite 4" spokes all around and a Jett Stream muffler.

It's a blast to fly!!!

since I'll need to swing a 15 inch prop, what modifications to the landing gear should I expect? I'm guessing with the small 2.5" wheels that come with the kit, a 15" prop may not have adequate ground clearance?

since I'll need to swing a 15 inch prop, what modifications to the landing gear should I expect? I'm guessing with the small 2.5" wheels that come with the kit, a 15" prop may not have adequate ground clearance?

I'm not familiar with the SK's but 15" seems like alot of propeller. I've had real good luck with the Top Flite wheels. They're about 4.5 " in dia. They're metric hubs so you need to "carefully" run a drill through them. The hubs are made of brass so they cut easy. The spokes kinda go with the World War One Eindecker/Stick and they don't catch alot of wind as they have a narrow profile and being spokes there isn't much of a side profile either.

The Fults tooling nose gear was one of the best things I've done for this model. It's super tough. I used the OS engine mount and cut out a piece of Plastic Delrin that mates to the stock fire wall blind nuts. If (When) I tear one up I can swap the whole front end in a jiffy....
I also went with real good hardware/horns/carbon pushrods/etc. that can be re-used and transfered over to the next victum.

One of the best things (I think) about the GP sticks are the replacement parts, much less exspensive than the Ultra stick parts. I tend to get "over confident" and buy extras. But that's how you learn right.

As a 60 size plane probably none at all. I try to get about one inch of clearence between prop and ground. My last build is a trike geared plane, my first one, I have always built tail draggers. I have about one inch of clearence and haven't had any prop strik problems so far but maybe using a Master Airscrew prop would be in order at first? I use MAS for trainers where I know there will be a lot of strikes and so far haven't broken any.
My plane was built from plans, a 60 size pattern plane and I bought the longest aftermarket frone LG as I could find but it just said 60 size on the package. Can't remember the make. The stick should be OK. Look up the specs on the plane and see what they have for clearence, you may need some bigger wheels/tires? Or you can use a three blade 14X7.

I don't understand the issue with clearance ... my Big Stick 40 is in EP and I have run a 14" prop without any real issues. There is a 1" clearance on that plane. So a 15" prop should be no issue on the Big Stick 60 ... However, most 91 2C engines are not very happy with a 15" prop. They run well with a 14x6 at the most.

Some of the other folks that have run a 15 inch prop on a big stik 60 needed to install longer gear or larger wheels so that the prop wouldn't hit rocks and dirt, etc. while taxing.

For the SK .91, it's recommended by a few folks to use a 15-6 prop as 14s tend to make the engine lean out.

a guy at our field uses a 55ax on his big stick 60 and it seems to fly beautifully. He said that little engine is more powerful than anything he used back in the days(not sure how long back) The biggest id go glow is a 75ax or 1154 stroke

Personally, I wouldn't use a 15 inch prop on that engine, although I would imagine one with a low pitch would turn ok, but the spin up time may be a tad slow due to the size... although I do use an APC 15-10 or 16-8 on my OS 1.20 AX's and turn them at about 9,500 RPM with no sweat.

The transition time with that engine is perfect with those size props, and you can imagine that it has pretty good vertical performance on both planes. (Venus II and Excelleron 90, both are pattern planes, about 9.5 pounds or so).

I use the OS .75 AX on my Skylark 70 and it too performs without any problems what-so-ever. I believe I'm turning a 14-8 or so on that plane.

CGr.

I have a Hangar 9 ultra stick .60, which is almost the same plane. I have a OS .61fx with some minor mods, and a 12*6 apc prop and this plane has loads of power. It will do anything you want it to. And it is still light and no clearance problems.

I am usually the guy with .25 size plane with a .46 in it, and the stick is not hurting for power.

I have the same plane and went with the supertigre 90. I do not like the ones that are made in China at all so it is the one made in Italy! No one seems to like the ones here that are made in China that I know of! You have to power up being up this high and going over is great! I moved the landing gear up and added a tail wheel to it and made a tail dragger! it is for sure going to be one of you favorit planes! Set the CG back a little and it is a fun airplane! Bob


Want to keep from crashing! Take off and land higher!

If you don't own an SK engine, you shouldn't give advice. they are a totally different design from the norm.

-They have smaller transfer ports and less advanced timing. This was specifically done, according to what the engineer at Kangke told me, to make a high torque, low rpm engine. The ports are not big enough to pass fuel for high rpm. The engine will lean out regardless of a rich needle setting.

-They are ringed engines, but have a tapered bore like an ABC engine. As such, they should never be run in a 4-cycle or rich except for short periods during break-in. If you run rich, the sleeve won't open up and the ring ends will be pinched together, causing excess wear.

- They have a very specific break-in procedure. It works great for the 3 SKs I have (2-90, 1-50). A 15-6 prop runs excellent on the 90. (It's really a .91 disp, but they call it a 90.)

-They are easy, 1-flip starting engines, have good torque. They pull an Ultra Sport 60 around great. I've had 2 SKs on 2 US60s.

As for bigger displacement engines being heavier, let's not jump to any "obvious" conclusions. Virtually all .91s and .75s are now made in a .61 crankcase. The OS .61FX & .91FX weigh the same. The Tower .61 & .75 weigh the same. The SK .70, .80 & .90 weight the same. The ST .61, .75 & .90 weigh the same. The GMS .61 & .76 weigh the same. The new OS .75AX is going to be right at the same weight.

As for 4-strokes, my Saito .91s weigh less than about any 2-stroke .61. I would imagine, but I haven't checked, that the Saito 1.00 4-stroke is pretty light, too. The 1.15, I know nothing about.

For a Big Stick 60, I can tell you that a buddy has one and has flown it with a ST .90 and a GMS .76. Both are great power for the Stick. A .61 2-stroke in my first US60 made it a nice little trainer. A .75 or .91 does it much better. You can always throttle back.

I have owned most of the engines I mentioned except for the OS .75 and the GMSs. I do have OS .55AX & OS 1.20AX, so I have the .75 bracketed. For a fairly new guy, the OS will be the easiest to start, tune and fly. Little or no break-in is needed. If you have the money, they are worth it. For the guy who wants to try something different, the SK carbs are excellent. I have used them on Tower and Evolution engines and they run better than the carb that came on the engine. Their mid range is nice and lean. I have bench tested and run half throttle for a timed 60 seconds, then oppped the throtle open and had the engine jump to full power, no rich blubber, no staggering, no quitting.