RE: 90 sized engine recommendation
 

I didn't catch that he was in Denver, which of course makes the engines less powerful. The problems with going too big are still there though. I have a .60 size stick that the former owner used a 100 Saito on. He said he couldn't get it to sit still at idle, couldn't land it without cutting the engine, and couldn't get it trimmed to fly right due to the weight and the torque issues. He had several wrecks that he blames on the big engine and wound up giving up on the plane.

RE: 90 sized engine recommendation
 

If you are a beginner then I recommend a .60 or .75 for a .60 sized sport trainer. A .91 four stroke would be good though. Power of a .60 but a bit better slow speed grunt.

RE: 90 sized engine recommendation
 

Get an O.S. Engine. You'll be glad you did.

If you want an engine that's harder to tune, get a brand other than OS.

If you want an engine that dead sticks on you in the air, get a brand other than OS.

If you want an engine that won't hold it's value if you ever want to sell it, get a brand other than OS.

If you want bad fuel economy, get a brand other than OS.

Just my 2 cents.

I really like it when I fire my OS engines up with 1 or 2 flicks of the prop and get my plane airborne and other are still fiddling on the ground trying to tune theirs with their cheap engines they have on them.

That's about like driving a rolls royce with a old beat up ford motor in it just cause you wanted to save money on the motor.

big dan

RE: 90 sized engine recommendation
 

S thunder tiger 91 2 stroke would give you the best bang for your buck, they have been compared to OS engines and although they have a slightly lower preformance spec, it isn't by much and the reliability is second to none, and as I said you can't beat the price

RE: 90 sized engine recommendation
 

Most dead sticks are caused by fuel line problems. O.S. is no more immune to this than any other brand.

I've over 34 non-os engines and there is no difference in the dead stick rates.

When I get a dead stick it is because of a fuel line problem, fuel depletion ( e.g. long downlines), mistuning, or as is usually the case that I'm merely let the tank get too low.

O.S. engines are more expensive up front to buy and more expensive to maintain because of the high cost of parts.
It is not that they "hold their value" better, but rather people seek more money when they go to sell them.

They get just as dirty as other engines, wear down at the same rate, etc.

Not that there is anything wrong with them.

I've purchased used O.S. engines then found that they were simply not worth renewing or repairing because of the high parts cost.

If you are getting different fuel economy, then you have a tuning problem. It has nothing to do with the brand name.

My OS .75AX burns exactly the same amount of fuel as my CHEAP Tower Hobbies .75 engine, and both pull the same plane in exactly the same manner.

The OS was MUCH easier to break in though. The T.H. didn't come into it's own until I had run about a gallon through it.

RE: 90 sized engine recommendation
 

The OS engines do seem to have better quality control and are designed well. They are the guaranteed performers. Other brands are trustworthy too though, even if there is the occasional one that needs some sealing done and takes a little more time to break in and get tuned right.

RE: 90 sized engine recommendation
 

None of his problems were the cause of the engine. These are 60 size planes I have built from kits or scratch. The Harley Extra 300 had the OS 1.20 FS but I went back to the YS 1.20, the yellow Extra is also another CG kit with a YS 1.40, the Hots is a midwest kit with a YS 1.10, the Daddy Rabbit is scratch and powered with the SK .91, it also flew with a SK 1.10, the 4*60 is powered with a Saito 100, the blue Extra 260 is running a SK 1.10 but went back to the .91 when I had to return the engine.
The Boeing bipe is scratch and had a OS 1.20 in it for years, I changed it out for a Brisn 40cc gas engine. None of them roll out or have any trouble with landing and all trim perfect. Low idle or tension on the wheels keeps them from rolling out. Building straight keeps the plane from doing odd things in the air that you can't trim out. The Boeing bipe is a giant though with a 68 inch wing, the 1.20 flew it but was really lacking when you wanted to show off and stunt it.

RE: 90 sized engine recommendation
 

the ST .90 is a great engine and is NOT hard to tune .

Hell i didn't even know that Denver still allowed fossils to be burned for a mere hobby :D

RE: 90 sized engine recommendation
 

Ditto on the ST-90...;)

I've had many, both G's and K's but I prefer the K model when I can find one, the G model is the replacement.

I use 15% Powermaster with a OS-F plug.

RE: 90 sized engine recommendation
 

I have the 60 size stik with the Super Tigre 90 even at this altitude it is great! I also turned it into a tail dragger! Every one needs to have just one of these in the hangar!

RE: 90 sized engine recommendation
 

Good points from both Carlos and Dan. I have been doing this for a few years now and the only Brand X :eek:engine I ever couldn't tune well were the MDS engines. Then it hit me, they were made for FAI fuel!!!! The engines ran better then but the castings were still crap and tended to break. If buying used though, here it comes, I only buy OS!!! I also only buy four strokes. I would also buy YS but you never seem to run into anyone selling them very often??? Why would that be???;)

RE: 90 sized engine recommendation
 

Grey beard , there are quite a few YS on the RCU market place , if your looking for used one,s and lots of OS too. Seems to be more as we get farther into winter , or picking up extra cash for X-mas?
I check it several times a day for kits, but can not resit looking at the 4s goodies.lol

RE: 90 sized engine recommendation
 

Thanks but I never buy on line, if I can't see it and check it out then I stay away. I like to go to club auctions, pretty good stuff and not much money!! I haven't done well finding engines but I have made a killing on kits! Like I'm the last builder left in the world or something, no one bids on them?

RE: 90 sized engine recommendation
 

O.S. 91 2 stroke would be my reccomendation. I've had about a half dozen of them and they have all ran perfect! Starts easily by hand. Turns a XOAR 14 x 8 at well over 10k

RE: 90 sized engine recommendation
 

Don't be afraid to buy here on RCU, 99% of our people are very trustworthy.
I used to buy and sell all the time for many years but for the last few I've gotten back into hot rods.

I never buy from a new member, some one with just a few posts to their name has no track record and could be a poacher.

I've never been burned and have never been asked for a refund, I've been disappointed a couple of times but that was my fault for not asking the right questions, communication is important and if you can talk to the seller even better.

RE: 90 sized engine recommendation
 

I have an ASP 1.08 2 stroke on the front of my U-can-do .60. The original carb was replaced with an O.S. carb... it hovers at a little over half throttle, will accelerate straight out of said hover nicely, knife edge loops (when I can manage to make my thumbs give the correct commands, anyways) and has been super reliable and easy to start.

RE: 90 sized engine recommendation
 

I've got a Webra .91 P-5 which i'm going to run on a Big Stick 60.

It should be a good match as it spins larger props than most other .91 2-strokes.

I've also got a 1.20AX in my Venus II and agree that itwould be way too much for a Big Stick.

RE: 90 sized engine recommendation
 

I had a goldberg ultimate 60 with that webra .91 on it...talk about an awesome combo, such a smooth running engine! It's getting hard to find parts for them now, right? I haven't found a needle valve for the carb yet, it got bent when I dumb thumbed it into the ground this summer ( belly towards me in knife edge about 15 feet off the ground and accidently snapped it over and didn't catch it)...I'm still sad.

RE: 90 sized engine recommendation
 

ST G90 for the price, the power, the ease of tune.
Just cant stand that ugly ass muffler.

http://www.youtube.com/watch?v=Y8-1i6Y4zYI

Seagull Exrta 300S 75/ST G90@14x4W APC 15% CoolPower MV

RE: 90 sized engine recommendation
 

Ditto,
And never buy a S.T.75 when you can buy a 90, their the same physical size.
The 90 is lighter and more powerful.

RE: 90 sized engine recommendation
 

I have a stik with a O.S. 60. It flys great with about 70 flights on the stik. of course you will need more than a 60 if u want vertical. the motor is from another plane and im aways able to hand flip just like my other 5 O.S. motors. and one of them is 10 years old. i never had any other brands, im sure there are other really great motors out there. but i have had zero problems. This is why i will stay loyal to O.S.
i have a 2ed stik thats not done, but i just got a O.S. 90 with a pitts that i will use next spring. anyone know of a good prop that i should start with?
thanks, tony

RE: 90 sized engine recommendation
 

Hello Hairy46,
I see you said u made yours a tail dragger thats what i want to do. did u use the same geer? also how far back from the firewall to the geer did u go? and last, how dos'e it handle on the ground now?
thanks for your help,
tony

RE: 90 sized engine recommendation
 

Tony from the front of the firewall to the front of the landing gear is 7 1/4 inch I beefed it up with ply and epoxy on the inside there before mounting the landing gear that came with it and used a Dubro 60 sized tail wheel assembly on it. it tracks very nice on the ground! Bob

RE: 90 sized engine recommendation
 

A good rule of thumb for a good handling taildragger is:

Have the main gear axle center line 2" ahead of the cg. As far as engines, my vote goes to the ST 90. Takes a bit more break in, but once it's broke in, it will last a long, long time. A Super Tigre engine is no more difficult to tune than any other engine, provided you know what you're doing and why you're doing it.

I refuse to buy an OS engine, the fact that they passed the buck and blamed the end users when their "wonderful" ABL cylinder liners peeled the plating doesn't speak too highly of their product support. That combined with the high cost of replacement parts leaves me feeling cold toward OS.

RE: 90 sized engine recommendation
 

DenverJayhawk

Let us know what engine you end up getting for your Big Stick 60.

big dan