Ok this is cut and dry. Either a Saito 100 or a O.S .91FX. I just want your opinion on which would fly this plane better. All around Performance.

No substitutes. Either Saito 100 or 91fx.

I had an OS 1.08 in mine in it was awesome. (plenty of power)

cut and dry 1.08

chadwickz71,

All around performance!! I have a Saito 100 and the OS 1.08. The OS is on my Ultimate. I thought about putting the 100 on there but I do not want any less power. If I was forced to make your choice I'd go with the 91FX just for the power but in the back of my mind I'd be wanting to put a Saito 150 on it. I think if you use the 100 it will fly and fly fine just different from the OS 91. I see my two strokes flying faster and my four strokes having a constant but slower speed. There are lots of people with these planes, maybe they will chime in with their thoughts.

Saito 1.00 no question. The two engines arn't really that close.

david

I have a YS 120 on mine and it is really a great performer. I have also reinforced a number of parts on the plane to keep it from coming apart.

Pat

I have an OS 120 surpass III on mine and would not want any less power. I tried it with a TT 91 4 stroke which puts out the same kind of power as the Saito and while it flew the plane ok It didn't have enough vertical performance for me. The 120 size is just right. From the two engines that you have I would use the 91 FX if it is a reliable engine.

Rick

David,

I'm curious why you say these two engines are not even close. I'm not saying they are. I would just like to hear your opinion.

Hi, name's Ken(Starfighter). My vote is neither of those. Mine flew AWESOME w/a ST .75 w/Pitts muffler. ALL the power you'll need, plus lighter than either of the others you are contemplating. A friend has it now, was gonna put the .91FX on it until his first flight w/the ST .75, and he was convinced that the ST was MORE than enough to get the plane to perform. If I had to choose between the engines you list, my vote goes to the .91FX w/Pitts muffler(Slimline will fit the best. Get the 70deg. exhaust outlets version. The Bisson muffler is too massive in design to fit well in this application.) That's my 2cents worth. Good luck!

well thanks guys but its about 50/50 right now.

Don't you just hate it when you say "No substitutes" and you still get a bunch of different engines? Oh, by the way...I fly mine with a Saito 150.

I have had several of the planes with different engines. I've had 90 to 120 ys. Ifound the 90 to be weak in the vert. The 120 made the plane heavy on the landins. My choice would be for the top power the new 110 ys( ihave one in the Cermark Pitts) or the Saito 100. Dennis

My.02 on the difference. I really should have ask how your going to fly it. If your going to do pattern/sport style flying. Then either engine would be a good choice. However for instant acceleration and torque the Saito 1.00 is the way to go. Swinging a 15x4W APC prop on 15% fuel that thing would be awsum. The .91 will swing a 14x4W or a 14x6MA but the difference in the way the it pulls the plane will be noticable. It's just hard to beat the instant power and ease of tuning and starting of a modern four stroke. As a bonus the stock Saito muffler can be turned to be barley noticeable. That will save you $50. for a pitts to fit the .91.
Neither of these engines will give it unlimited verticle, but for my style of flying the 1.00 would suit me best.

David

A guy at my field runs a YS 120 in his... can you say VERTICAL ????????

Saito 100 with 15x6 APC with Red Max 30% nitro, 19% all synth oil with OS F plug turning 9600 RPM. Plenty of power.

does anyone have a price for the arf and kit and how does the kit build up.thanks

The Saito, will give you great performance and likely scale performace.
Mine lands tailwheel first. Aerobatics do not require a great amount of speed.
Knife edge loop will require a little more power.
I swaped to the YS 1.20 with a Graupner 14x7 3 blade and it's just right.
this was the older YS ...non- air chamber.

I have the Saito 100 in my Blue Hawk running a 15x6, plenty of power to hover, and I think it is the perfect app. for this plane, not over powered but also not underpowered, just right for all your aerobatic needs!

os 91 fx apc 15/6 rpm 10,600 it turns a little more than the satio will but runs on 15% nitro

I fly my CG Ultimate with 91FX, 15x6, sea level, 10% nitro 18% oil, fuel pumped, I have tested 13x8, 14x8 & 15x5; so far I like 15x6 the best; rich engine, ultimate aluminum spinner, slim pitts muffler.

I believe the secret to enjoy this particular plane is to keep it light, I have seen it flying with 120 4-s and with 75 2-s I like my combo better so far.

I do have a SAITO 100 ready to intall in a finished MIdwest mini CAP232, however being my Ultimate close to general maintanace day I may try the SAito 100!

If you go with the FX and bigger prop, you need to open your cowling more than normal and have your engine on the rich side, so no over heating happens o.k.

Keep it light and put the OS in it would be my choice.. I had one built light years back with an old SuperTigre .90 in it. Bare in mind this engine went through heck in a P47 previously, and the carb was glued in place with JB Weld.... A good OS 91fx would be VERY nice IMO. I could knife-edge loop the ultimate with that tired ST90.

I have a Moki 135 running an APC 16 x 8 in mine - er....."adequate" describes it!

I've had 4 or 5 now just keep putting my old O.S. 91 in them and it flies great. Were at 3900 ft. here that 91 pulls it just fine with 15% Cool Power and a APC 14-6 prop. The plane needs no extra weight ,I agree with the "keep it light" posts.-Mike