I've got a friend who is planning to purchase a Sig 4 Star 60 ARF. He wants to put a 2 stroke engine in it. Which one do you think would be best? What about the Irvine .72? I haven't seen much written about it. Thanks for your help.

The Irvine .72 is one of the best kept secrets in this hobby. It runs much like a .91, only quiet and pretty.

I fly a OS91FX, at our field almost everyone flys a 91 2S or a 91FS, one guy just installed a 75 2S Tower it flys great after a slight break in headache.

Tell your friend if he looks carefully....the recommended engine size is shown on the box the model came in.

'Race

"I've got a friend who is planning to purchase a Sig 4 Star 60 ARF. He wants to put a 2 stroke engine in it. Which one do you think would be best? What about the Irvine .72? I haven't seen much written about it. Thanks for your help."

Race,

If you will CAREFULLY...........reread my original post, HOPEFULLY..........you will notice that I said that he is PLANNING to purchase this plane, so at this point he has no box to look at. Also, if you will look CAREFULLY..........HOPEFULLY....... you will notice that I did not specifically ask what SIZE engine to put in the plane. I have talked to people with a range of engines in them from .61-.91 and they all seemed to be happy with their choices. I just wanted a little CONSTRUCTIVE WISDOM and advice from the members of this forum. I have found the MAJORITY of them to be very friendly and helpful. I wasn't looking for or expecting SARCASM to what I think is a legitimate and reasonably intelligent question. I'm not sure what provoked this UNNECESSARY and TOTALLY WORTHLESS response from you, but in the future HOPEFULLY........... you will spend more time CAREFULLY............reading a post before replying to it.

DIRT DAUBER

P.S. Thank you to hobbsy and Checklst for your LEGITIMATE AND APPRECIATED responses.

My YS91AC was awesome but a little too much for the 4*60, but my TT Pro .61 is OK but possibly a little weak. It flies OK with the TT 61.

Any reliable 60 size 2 stroke engine will provide excellent power for the 4-60 as will any reliable 91 4 stroke.

I had a 61FX on mine running a 12X6 prop on 15% Nitro - this combination gave me unlimited verticle which was fine for my needs. The Irvine 72 will likely offer more power.

I have something a little different in my 4*60 with a Fox 74.
It took awhile to break in but it now has great power and
reliability.
Just another option but I also like the idea of the Irvine 72.

Sam

Gee whiz Dauber...

I did read your post.

Note that the Four-Star's come in (3) sizes....40, 60 and 120.

Therein lies the answer to your question.

Here in the computer age...information is SO easy to get.

Irvine .72? Probably a fine choice. As would be any decent 60-75 sized 2C engine or perhaps up to a .91 Four stroke.

You can go larger of course, but then the model turns into a home sick manhole cover at low power.

I am plenty familiar with this plane. A Saito .80 for example does a fine job with it.



'Race

SDM, I have a Fox .74 on my FourStar 60 converted to Diesel.

The Irvine is a good choice, but any .61 is plenty of power as well.

If all you want to do is fly around the field without a lot of vertical maneuvering, then a two-stroke 60 will be fine. However, something like the Tower .75 being basically a bored out .60, you get significantly more power for less weight than the standard .60. I had a Tower .75 on my 60 size Easysport, and it was great to pull 150' diameter loops, or make a low & slow pass and accelerate up at a steep climb angle, do outta sight stall turns, etc. I have flown a friend's 60 size 4* on a Saito .91. I love the chug-chug of the Saito, and it was adequately powered, no complaints, but did not have the zip of my Tower .75. I liked my Sr Kadet with a Saito .80, and I'm sure that would be a good choice if your friend is just moving up from a high-wing trainer. Tower .75 is great value, plenty of power, and of course you don't have to fly at full throttle all the time. Only quibble on the Tower .75 is the muffler attachment screws require a snub-nosed allen wrench and half an hour to put on/take off.

Thanks to all for your help. I've learned that it never hurts to get the advise and opinions of people with more experience when you can.

Race...... :thumbup: ........That's what I was looking for. Thanks.

Dirt Dauber

Hello; I know you might want a two stroke opinion, but my experience is with flur strokes. My 4 star 60 has an OS 90 in it, the old one with the pushrods up the back. Flies great, big prop, The other one in our area had an OS 91 Surpass in it. He could hover and hang on the prop with that set up. I suppose a 2 stroke could pull the plane around too.

I went a bit nuts and put a supertiger .90 in mine. Originally had a .75 but I wanted more verticle. This plane is a blast with a .90 Verticle till you can't see it then snap till your 20 ft from the ground. Now that's my type of flying. Plus the .75 and 90 have the same crankcase.



Neo

I have a Four Star 60 with an OS .61 in it. It flies great, but on our hot summer days, and with our altitude here in Idaho, there are times when I really wish it had more power. The OS .90 is the same size and weight as the OS .61, and would be a great choice. I wish I had gone that route, and probably will in the future. If he is buying a new engine specifically for that model, why not spend a little more, and have a MUCH more versatile engine? Feel free to e-mail me with any questions regarding the Four Star 60, or the OS .61 I have in mine. I'll be glad to help!

Hey Dauber:

I fly the 4 Star 60 with the Irvine .72 for power --- I can tell you that it is a fantastic combination --- vertical is almost unlimited --- the engine puts out the power of a 90 with the size of a 60 !

You won't be disappointed with combination !

P.S. the tank that comes with the ARF is terrible --- either replace the stopper or by a DuBro replacement tank

Hope this helps,

HAL

But the OS .90 IS a .91, with the weight of a .61......and they start SO easy, and idle SO nice!
I've had many gallons of fuel through my 4Star 60, never had any complaints or problems with the tank or stopper. Maybe they've made a change in the last year???? Mine is an ARF...........
I would advise going to a fiberglass landing gear, as well as a better quality tail wheel assembly than what comes with them.

Dear Donkey Doctor:

The PIPE here yet AGAIN...and at http://www.rcuniverse.com/showthread...13&forumid=107 in the Kit Building forum I've got a thread going about kitbashing a Four Star 60 into a sort-of "Agri-Batic" CROPDUSTER, with an all-new fuselage and MOONEY private plane shaped tail surfaces!

And I'm going to be using the same EXACT engine you've got on yours-an early 1980s vintage OS FS-90 REAR camshaft motor, that's in need of NEW bearings to replace the old, worn out, varnished-up ones...and the new bearings just came in the mail TODAY from Boca Bearings in Florida!

Just check that thread out...and if you've ever wanted to know, the FS-90 has the same EXACT exhaust port threading as the currently produced FS-91 Surpass does (found THAT to be true last Saturday, courtesy of my LHS) so if you DO ever happen to lose the muffler on your FS-90, an FS-91 Surpass unit WILL thread into your engine's exhaust port JUST FINE!

Hope you can give that thread a look...when you've got the time!

Yours Sincerely,

The PIPE! )

I have a YS 91FZ on my 4*60 with an APC 15x6 and it is the perfect combination. I have flown others 4*60 with a saito 61 which was fine, but lacked significantly in the powerband. The YS may be a little too much, but throttle control is no big deal. With this motor, I can hover, knife edge, waterfall, etc... I also modified the rudder and added 1 inch extra to the rudder and elevators. Dual servos on the elevator also, with a pull-pull rudder set up. A Saito 91, 100 or OS 91 will also fly these fine. But all these are 4 strokes and you mentioned a 2 stroke. So any powerful 2 stroke above a 60 should fly the plane fine, but I would still recommend considering a 4 stroke.