Just purchased a Sig four-star 60, also a Saito four stroke 91s.
Was this a good choice for the sig 4star 60? The kit is still in the
box, any changes or ideas to make the arf better? Any info
would be appreciated. New to the hobby (two years)

oops - voted CG is a problem. It will not be. Mod fix my vote?

The tail wheel, although it's not as nice is as a Sullivan, will do fine if you manage to solder it properly.

great plane (well the kit is - haven't seen an ARF in action).

The poll's math seems a little off for check-box style.

Adam,
The 91 will work fine. See you at the field this weekend?

You'll love the combination. I have the same set-up. It has plenty of power & it's easy to balance with no extra weight.

my four star 60 fly with a os.91 surpass (same style of engine)
you will love it

mine has the thundertiger 91 4st. I love this plane, always end up flying it the most often. used a sullivan tail wheel assembly, instead of stock. no problems.

Went with a Magnum 91.

Replaced the tailwheel with a sullivan.

Didn't like the rudder and elevator pushrods.
I experienced trim issues when flying in
different weather condiditons.
Went with 4-40 rods. The sleeve for the 4-40 rods
fits right inside the existing pushrod sleeves.
Have not had to retrim with this setup.

No real CG issues. Have the battery up underneath
the fuel tank.

I really like the plane.

Mark

Flying a Saito 90 - had to add ~8 oz to the nose for CG.
Replaced tail wheel with Sullivan. Replaced push rods as well.

Wing had twist that required a little strategic reshrinking to straighten.

Love the plane.

Should have asked in previous post:
What are others experiencing relative to fuel tank size? The Saito 90 is my first 4S. After 10 minute flight, the tank is close to empty. Have not run dry yet.... Don't remember tank capacity as I write this. Just saying you may want to look at it. On this board some are of the opinion that Saito's gas mileage is inferior to others. Any thoughts?

Your going to love this plane after 22 years of building kits this was one of my first ARF's, and it was vary well built .

I did tinker a bit (just an old habit) like BGI I did not like the tail wheel and used a Sullivan(great engineered product)not cheep but anything good never is. I also took a 3/4x1/16 aluminum bar stock and reinforced the aluminum landing gear I thought the stock gear was a little soft.

Pay close attention to the Fire Wall I have noticed most arf,s are not gluing the fire wall vary well(well not up to my standards anyway) put some epoxy and triangle stock on the back side. Please use epoxy or dope to do a better job on fuel proofing the fire wall ( I use 3 coats of dope)and make sure you get the seams sealed.

Good luck!

Thanks to all that answered my questions on the sig four star
60. This has to be one of the best sites ever for info on all
kinds of problems and fixes. Adam Tapps

I recently purchased a 4*60 ARF (second plane after a Hangar 9 Ultra Easy/MDS 40) and put a Saito 80 in it. I'm not quite finished with it yet, but have mounted an run the engine, which seems fine. It seems easy to start after the MDS, which after 5-6 tanks of fuel still is finicky. It certainly looks beautiful in the engine bay.

I did notice from the engine manual that the 80 weighs 20 more grams than the 91, which was surprising. Is the power and weight penalty likely to be noticeable?. Would I have been better off with the 91?

I have a Saito 90 in mine but I fly at part throttle most of the time so I would suspect that an 80 will be OK. It won't be overpowered but should be sufficient.

Mine needed a half ounce of tail weight with the TT 91 FS. It's a heavy engine so yours may balance just right as is.

Congratulations on your purchase.
I have had a 4-star 40 and I consider it one of the best aircraft I have owned.
As for modifications, there aren't many.
I strengthened the rear fuselage by gluing in som strands of carbon fibre behind the rear wing mount because I had heard that this was a weak area. I don't now if this action was necessary.
Also, I used a DuBro (or was it Sullivan?) tail wheel bracket, instead fixing the tailwheel directly to the rudder.
One thing you might consider is to shorten the wingspan by one bay each side, by mounting the ribs proportionally closer to each other. Apart from reducing the wing span somewhat, the plane becomes a little bit more lively in the roll and the landings become easier (with the big wing it will glide forever).
Also, when you get some experience with the flying characteristics, consider moving the C.G. around a little bit.
With some tweaking you should be able to get the aircraft to fly straight and level both inverted and right way up without any trim change. This is the only aircraft I have had that could do this.
The only flying characteristic I didn't like was the rather strong nose-down pitching tendency with rudder application. It seems to be a characteristic of all 4-stars and if you are aware of it will not cause any problems.

/Red B.
Sweden

Red,

Thanks for your helpful and informative reply. I flew my 4* 60 for the first time yesterday, after many long nights finishing it up. I ran out of time and only flew it once (I also wanted to take it home in one piece after the first flight), but it flew magnificiently. Despite my relative building inexperience, it needed very few electronic trim adjustments to fly straight and level. Takeoff was easier than my high wing trainer (Hangar 9 Xtra Easy), and the landing was exceptionally docile. Even though the touchdown was very gentle, it did seem to want to keep flying, after 2-3 gentle bounces. To me it seemed easier to fly than my trainer, and I thought it could easily have been a first airplane.

I may do the modifications you suggested to the tail, and possibly the wing after I gain more experience with it. It does seem a little weak behind the wing. Even though there is a small plastic E.T. (at the request of my daughter) serving as pilot, I'm somewhat puzzled as to why I had to add 6 ounces to the nose to balance it, since it has a relatively heavy (540g) Saito 80 4-stroke mounted. But, that means I can both strengthen the tail signficantly, and get rid of some of the lead. Right now, it weighs exactly 8 lbs, which is at the outer limit of the Sig's predicted flight weight. However, it's certainly not underpowered.

Thanks again,

Clay