In the late spring I'm thinking of getting a cub to put on a floats, either the Goldberg ARF or the Hanger 9, or GP, haven't decided which one yet. I'm wondering if a four stroke would be better because it has more torque but I wonder if the two stroke would be less of a hassle because of less parts. I want to make the cub STOL capable so I want to consider that as well. Any thoughts?

4 stroke for the torque and the sound....

If you want STOL abilities go to a oversized 2 stroke. I do this 2X the rated C. I. size on every plane I have.

Build the plane. Get all your rc in place & woking. Mount the fuel tank. Install the floats. Mark COG to balance point on the wing with tape. Put a piece of Balsa under each C O G point on each wing...To prevent digging dents into the wing when you do the next step.
Start adding weight on the engine mounts. Keep adding weight till the plane balances. That is the weight of the engine your plane needs to fly in ANY wind and it WILL STOL.

You should be able to hold the plane vertically and have it fly straight up & out of sight.
The plane will normally fly on 1/8 to 1/3 of throttle & sound perfect.
I Have found only 1 slight problem. Idle speed can be a little to high. 1 plane. a Spitfire must be flown to 6" of the ground and I stop the engine to slow down for a tail wheel landing.

Overpowered plane is a joy to fly.

definitely 4 stroke......your neighbors will appreciate it too!

I have a lot of overpowered airplanes, but in the past couple of years, I have been changing out all my seaplanes to 4-strokes. My old Sig Fazer on floats started with a Tower .46 and I flew it that way for 4 years before replacing it with a Saito .72. I liked the plane much better. The torque of the 4-stroke seemed to get it off the water very well and it pulled well in the air.

I don't know if it's the fornt vs. rear carb, but a little splash seems to kill the 2-strokes a lot easier than the 4-strokes. Personally, I'd go with a 4-stroke on the Cub seaplane. Save the 2-strokes for land planes.

If the engine winds up in the water, a 2-stroke is MUCH easier to clean out. Run the 2 stroke for 5 minutes at high throttle and the water is gone. With a 4-stroke, you have to take it apart to get the water out of the crankcase, cam housing and rocker boxes. If you don't, you will be taking it apart to replace the bearings in a week or two anyway.

So there you go. 4-strokes for the guys who never crash or land hard, and 2-strokes for the reat of us.

Jim

I don't agree. 2 or 4 stroke, after getting the plane out of the water prime the snot out of it and start it by hand. Be carefull with an electric starter as it may be hydro locked. When it starts fly it. after the flight all the water will be gone. If you can't fly it at least start it and run it for a few minutes.

I've been doing this since the mid 70's and haven't taken one apart yet nor had to replace bearing or anything else. In fact while doing two tours on Guam I flew alot on salt water and after flying I would do a fresh water rinse and start them up to dry them out. Never a problem.

Only Thing I would add is to first remove the glow / sparkplugs & use a electric starter to blow the water out that way first. Then put in a dry plug and start it up as usual. Run it four a couple of minutes to really heat up and dry it out.

4 strokes do not like being submerged. Same for full sized outboard engines.

Rich

Hi Fellow: From all that I have read, the answer to this question is simply a personal one. Choose the engine you love, and live with any mechanical, or operational difficulties if any. I prefer the two stroke for its simplicity. As a retired aircraft mechanic, nothing would please me more than toying with the inners of a 4-stroke, but the two strokes give me just enough fun to keep me happy. In dealing with a widow's husbands hobby inventory, there were many new Saito 4 strokes. The 150 Blacknight was a prize to hold physcially, but priced near $400.- it was something to expensive for me to purchase, and then dare to put it into the air.

Xtratorque: Have fun choosing you engine.

AERORICH

I'll probably go with an O.S. or Saito 4 stroke. I have a Saito 125 that I'm going to put in my Cessna, but I'm not gonna put that on floats. Thanks for all the help.

Hi I guess its a matter of choice, but I went with a 4 stroke on my floater, using a YS91 on my bitzer (mixed heritage parts) 79" ws. plenty torque, sounds great and very reliable