Model 5 Continental Performance

[Steve-TX]

I thought the recommended static RPM for an O200 was somewhere around 2300? Your 2700 static and Steve's 2500 seem a bit high to me considering that the max RPM is 2750. Might be something to check into.

I like that idea too. I’ve been meaning to get more familiar with manually adjusting the prop pitch anyways.

[Steve-TX]

A follow-up. I changed my WD prop drive to 11 degrees. It measured 8 degrees before I changed it. A static runup resulted in about 2250 rpm, after the change. I flew it and although takeoff performance was noticeably less I gained about 10-15 knots in cruise. WOT during flight got about 2400 rpm. I plan to change the pitch to 10 degrees to get the static rpm to 2300.

Back to the float idea. I think my plane may get off the water once I install the Full Lotus 2350 floats with the amphibious gear removed. I should try it on a cool fall/winter day versus in the heat of the summer for best success chances. I’d like to get some advice and help making sure the rigging is right. Not a lot of float planes and pilots in TX. I will get the factory manuals but and follow them to the best of my ability. If any of you feel up to the challenge of helping me with this project via phone/Skype or even in-person, please let me know. I can’t imagine I’d be the first Model 5 with an O-200 on floats, or am I?

Once I install the floats, I may have to reduce the blade pitch again.

[airlina]

You should be able to get to rated RPM (on my continental IO-240 it is 2800RPM) so the 2400 RPM you are seeing with full power level flight is too low, you should be seeing more like 2750 which I believe is the rated limit on the O-200. Keep playing with the pitch till you can achieve this. My full power static RPM is about 2350 RPM and rated RPM of 2800 is achievable at full power level flight. I have a Sensenich wood prop . Bruce N199CL

[av8rps]

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!

[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!

[Maverick]

My last KF5 had an 0200-A with a 70" three blade Ivo-Prop. I set the pitch according to the RPM. Initially, I had the pitch too high and was getting 2450 RPM and 125 MPH. I flattened the prop so max RPM was 2750. My speed came down to 115 but my climb improved significantly. I generally cruised at 2550 RPM @ 110 MPH. My flying buddies were running 912ULS and could out-climb and out-run me so with this build, I'm using the 912ULS.

[mr bill]

To get more power from an O-200A, install pistons from the O-200D. They raise compression from 7:1 to 8.5:1, you will get a real 100hp.

[Steve-TX]

My last KF5 had an 0200-A with a 70" three blade Ivo-Prop. I set the pitch according to the RPM. Initially, I had the pitch too high and was getting 2450 RPM and 125 MPH. I flattened the prop so max RPM was 2750. My speed came down to 115 but my climb improved significantly. I generally cruised at 2550 RPM @ 110 MPH. My flying buddies were running 912ULS and could out-climb and out-run me so with this build, I'm using the 912ULS.

Hi, Maverick. I seem to be following your path and right now I’v got too much prop pitch. I’ll back it off some by reducing pitch to get better numbers. Your experience with O-200 vs 912ULS makes me think that if I am not successful getting off the water like the previous owner then I may have to make a drastic change and consider swapping engines and/or floats.