Model 5 Continental Performance

[Steve-TX]

I fly a 80 hp 912 ul on amphib floats with an IVO IFA prop, and it works great. In many regards it is a little hotrod. But it's under 800 lbs on the floats. Keeping the weight down is a huge advantage with the smaller wing area of the Kitfox, which is the primary reason the 4 is easier to make work on floats.

However, I can't see any reason that an 0-200 Model 5 won't work as a floatplane. It will probably never perform like the 100 hp 912 model (much lighter) but it should still make for a fun floatplane.

But, 2350 floats are way too large for a Kitfox. 2350's are for a Husky or Glastar. 2350's would be large even for a 150 hp SuperCub. With a Kitfox in the 850 range empty weight (on wheels) I would suggest a 1550 to 1650 lb float (buoyancy being typically higher than number on float). Paul L's IO-240 Kitfox flew on Murphy 1800 amphibs if I remember correctly. And those were probably a bit larger than he really needed, but he did get them to work.

With that said, once you have properly sized floats on the plane, you should set the prop pitch so that you know you will overspeed the engine with wide open throttle when straight and level. Yes, it's going to be set really flat. And yes, you are going to lose cruise speed. But it's a floatplane so you won't really care with all the fun you are going to be having

You need all the takeoff power you can get. Floatplanes take a lot more power than a landplane. They have to plow through the water to get on the step, and then have to break the suction of the water in order to leave the surface. Land planes have none of that to deal with, so getting a floatplane set up properly can be difficult by comparison. But I can assure you after waterflying for more than 3 decades, it's worth the effort!

Av8rps, thank you for that information and renewed motivation. Yes, I can easily sacrifice speed with floats. Many, many apologies as my Lotus floats are 1450’s; not 2350’s as I mistakenly wrote. Only a 900 lb error! A previous owner said he couldn’t get it on step and thought he had the right help with rigging. I’m not totally convinced my heavier Continental O-200 is performing as it should be yet but I’m playing with prop setting to see if adjusting it helps. I’m not an A&P and I’m fairly new to plane ownership - 1 year. I’ve had a conversation with Kitfox and the nice lady I chatted with did say the Rotax 912 engine weighs in 80 lbs lighter and if I could start over knowing what I know now, that would be my engine for that very reason. If I can get my plane safely in the air with no amphibious gear, I’d be a very happy Kitfox camper!