Firstly, thanks to all those who responded to my request for instructions in a previous post of mine. It never ceases to amaze me at how helpful and kind nearly all folk are in this hobby. There are so many willing to share their knowledge and help with others.....what a great hobby this is

So now I am seeking your input on what would be a suitable power plant for the CG Ultimate. I would like a four stroke but to be honest that is out of my price range. Should I be looking at say a 90 size two stroke? I had a new GMS 47 a while back and was impressed with it, how are their larger engines?

I have been flying my Sig Hog Bipe for a few years now and have greatly enjoyed it and am really looking forward to getting this Ultimate in the air as I have read many great things about its flying abilities.

I appreciate any comments or thoughts.

Cheers

Mike

I am building one now. What I will be using is the OS 120 4 stroke. The 4 stroke is out of my price range also, new that is, I bought the OS here on RCU as a used motor about a year ago and got a great deal on it. The motor has run perfectly. And I didn't have to bother with the break in process.

So far I have taken advantage of 3 used motors here on RCU, I have been happy with all of them.

I have seen this airplane fly with a Super Tiger 90 2 stoke. Great motor with more than enough power.

hope this helps.

tonyc

I fly my Ultimate with a ST2300 and a quiet tuned pipe. 16x8 apc prop. This combo will pull the Ultimate out of a hover with authority!

I also have another Ultimate with an OS160, slimeline smoke muffler, TME smoke pump, 16x8 apc prop. It will be finished in a week or two.

I also had an Ultimate with a ST90, 14x6 MS prop, it could hover but would not pull out vertical.

Go with a 140, 160 2-stroke!

I think it really depends on how you intend on flying the plane. I'm flying one with a Saito 120 right now, but I also had one with an OS FS91. The flight characteristics are completely different. A bigger, heavier, engine will feel more like a hot-rod. A smaller, lighter, engine will be a better all-rounder. In my opinion, the sweetest handling will be found with an engine weighing 24 ounces or less. This will limit your choices quite a bit. If you're also on a tight budget, you really only have two choices. A very strong 60 or a light 90. If I were buying a 90 2C, I would look very carefully at engine weight with muffler and probably choose the lightest one. The MVVS looks good. You may also wish to side mount the engine and use a Bisson muffler. This will save you a couple ounces but cost $40. In all honesty, I think the Saito 100 is a perfect match for this airplane. It will give you everything short of 3D performance. If you're going to do hoverbatics, you'll need more power. A TT120 two stroke would be a monster for little money.

BTW, my current flying style is more IMAC oriented. I use the power of the Saito 120 to draw long vertical lines. I only hit full power 10% of my flight regime. It lands like a brick with parachute deployed. My airplane is 8.75 lb.

YS 91

I did a little research. If you're really on a tight budget, the Magnum 1.08 looks pretty good. It's rated at 24 oz with muffler. Street price is under $150. The Bisson muffler is $46 (you can use the stock muffler, but it will require a large ugly hole in the cowling). I think you would be quite happy with this combo. I can't vouch for the reliability or durability of Magnums though.

All the 90's I looked at were quite heavy except the MVVS. Unfortunately, it will cost about $230. You may or may not need a different muffler for this engine. The ST90 was interesting because of the swivel muffler. This would work well in an Ultimate cowling. Unfortunately, the power/weight on this engine doesn't look too good.

I was very close to trying the YS91. I changed my mind at the last minute for two reasons: 1) I got an excellent deal on the Saito, 2) there is a very large Saito experience base in my club. It turns out that the Saito 120 is a very sweet running, user friendly engine. Highly recommended.

Thanks for all of your replies. Thanks for your research ilikeplanes

How about the OS 91FX, it is rated at 2.8hp and only weighs in at 19.3oz, just a hair lighter than its smaller brother the 61FX! There seems to be some good buys around here on RCU, looks like it might be a good match?

Thanks again

Mike

My Ultimate is nine years old, and I have an ASP 108 in it, with a Slimline Pitts style muffler, 10% fuel, and I use a 14x10 APC prop. With this set-up, it is a nice flying airplane with scale like performance. A buddy has one with a 108 OS, and we propped it with a 15x8 to slow it down a little for him.

I think the Magnum 108 would be an excellent choice. It is a "nicer" version of the ASP I believe.

My Ultimate weighs in at 9 3/4 lb on honest scales.

Clair

Canada Goose:

I fly my CG Ultimate with an OS 91 FX, 15x6 .
It flys so nice and landings are not that fast, aerobatics are gooood !!, with this combo, you need to really open the cowling otherwise the engine will heat-up; The plane fly just like it had a 4-s.