Classic Model 4 1200 vs Model 5

[NewFlyer18]

Hello,
I’m new to flying and in the market for a kitfox but would like to know the difference between the model 4 and the model 5? I’ve seen a lot of model 4’s for sale and not so many 5’s. What research I’ve done looks like they are really close?
Thanks

[PapuaPilot]

The short reply is that the model 5, 6 and 7 are all very similar, and different than the model 4. The later models have a larger fuselage, higher gross weight and was made to use larger engines than the model 1-4.

The link for history is no longer working at the Kitfox website.

[Slyfox]

The short reply is that the model 5, 6 and 7 are all very similar, and different than the model 4. The later models have a larger fuselage, higher gross weight and was made to use larger engines than the model 1-4.

The link for history is no longer working at the Kitfox website.

wow! I think I'm offended. I have a 4. I love it. It feels very personal to me. meaning it fits me. I have one of those big engines. yup the 912uls the same one that is standard for the model 7. Now I play big time with my plane, I have big tires. I feel the advantage of the 5 thru 7 is it's for the big person. yup, I'm a small guy 5'6 or there abouts and 175. so I fit perfect in the 4. It's like the 2000 Silverado, my truck, fits me real nice. I get in the newer chevy's and they seem so big. they are made for the BIG guy. sure I can drive them, but I love the feel of mine. same with the kitfox's the higher number fox's are bigger. more robust. have a higher payload. I guess you can go for whatever you want, but if you fit in a 4, that's a plane to have. it can give you some fun factor. just my 2 cents worth.

[jrthomas]

My personal opinion is that the Model 4/1200 in in a class by itself. Outward appearance is similar to the Models 1 thru 3 but otherwise it's a totally different airplane. The controls are different, they fly different and they perform better. The 4 has a totally different airfoil than the earlier models. The vertical is much larger and the control rigging is much improved. The Model 4 with an equal Rotax 912 will outperform the 5 thru 7's in about every area. The Models 5 thru 7 moves the engine forward so heavier engines work better on these than the model 4. They also can carry much more weight in the baggage area without getting into an aft CG problem. Kitfox made a giant leap forward with the Model 4/1200. The 5 thru 7 are more refined. All are good. I love my 4 with 912, Grove gear and fat tires. I'm sure I'd be equally happy with a later model. You can't go wrong with either.

[NewFlyer18]

I really appreciate all the feedback. I’ve found a model 4 that I really like and plan to take a better look at it. Thanks again it was very helpful.

[av8rps]

The Model 5 though 7 are really great airplanes, and because of their slightly increased cabin size, baggage area, and strengthening allowing for a 29% gross weight increase, that all makes for a pretty versatile airplane for the average guy.

But those nice improvements increase the average empty weight about 25%. And considering that the newer Kitfoxes and the model 4 use the same wing and tail, performance is going to be less on the newer models with the same power as the wing and engine has to haul more weight. Unless you are willing to go all out and spend the big $$ on a 915is and a STI wing, the Model 4 with a 100 hp Rotax is going to outperform the newer models pretty significantly. I would speculate that a 912ULS powered 4 with a standard wing will perform on par with that 915 powered Model 7 STI, but that is speculation because I have never flown a 915is STI. The 4 for sure would be faster in cruise.

Now I'm not knocking the new Kitfoxes, as I personally really like them and have many times contemplated upgrading. But I fit in my Model 4 really well (at 6 ft 1" and 190 lbs), and even with only a 80 hp 912ul and a 250 lb set of amphibs hanging underneath it, it still performs great. And of course, I have significantly less money in it than I would have to pay for a newer model.

And yes, you can typically buy a Model 4 for much less than a Model 5, 6, or 7. That doesn't mean the 4 is that much less of an airplane. The price difference is more reflected in what the original builder spent building it back in the early 90's as opposed to what it costs today (eg, a new 912 was under 10 grand back in the early 90's and the kit was 12 grand). So back in the 90's you could put together a nice Model 4 for 25 to 30 grand. Today, a Model 7 SS will cost 65 to 75 grand. That really is the primary reason why there is such a price difference. It isn't that the 4 is half the airplane. In fact, I would say the 4 is 90 percent of what the new ones are in overall usefulness, and 125% in performance.

But again, they are all great airplanes. The cool thing with the Kitfox design is whatever your taste and budget, you can have it your way.

You can't go wrong with any Kitfox in my opinion...

[GMKman]

wow! I think I'm offended. I have a 4. I love it. It feels very personal to me. meaning it fits me. I have one of those big engines. yup the 912uls the same one that is standard for the model 7. Now I play big time with my plane, I have big tires. I feel the advantage of the 5 thru 7 is it's for the big person. yup, I'm a small guy 5'6 or there abouts and 175. so I fit perfect in the 4. It's like the 2000 Silverado, my truck, fits me real nice. I get in the newer chevy's and they seem so big. they are made for the BIG guy. sure I can drive them, but I love the feel of mine. same with the kitfox's the higher number fox's are bigger. more robust. have a higher payload. I guess you can go for whatever you want, but if you fit in a 4, that's a plane to have. it can give you some fun factor. just my 2 cents worth.

I think the big engines Phil is referring to are the Lycoming, Continental, and 914 turbo engines that are an option in the 5,6,7 not trying to offend anyone.
I have the Continental and I can cruise at the 140 mph vne of the higher Kitfoxes (not that I would). I think the model 4 has a vne of only 125mph. I could be wrong on that.

[jrthomas]

The Model 4 Speedster has a VNE of 140 according to my build manual.

[GMKman]

Nice!! I like that.

[Hockeystud87]

Hey my grandpa kept his model 4 at Wattsonville as well! Did all his test flying out there.

I remember years ago asking a Rotax rep about the results they obtained after flying their testbed Model IV Kitfox Speedster that they had put a 914 on. He said the Speedster with the new engine would hit 140 in a mild climb. Unfortunately they felt the Speedster was so overpowered that they weren't going to promote that engine in that airframe. Funny, I didn't know you could overpower a plane until talking with him...

Alright I'm gonna bite. So I was under the impression the 4 wasn't able to fit the larger motors on them. I assume this would require a custom firewall/mount and aft balance adjustments?

Also if you're pulling 140 in a climb that would make me think you'd have to lug it just to stay under VNE in cruise. IDK how good of a setup that would be. Maybe if you had a adjustable prop you could play with pitch to not have to lug the motor in cruise. The pitch it more for fast climb?! IDK how that would work. I had a RC plane that I did a similar thing like this to. So big a motor up front I literally put lead in the back for balance. I could hover it at about 1/2 throttle and climb away fast at full throttle. I only cruised around 1/4 throttle. I think at some point your engine is so much power you're just not able to run it appropriately or how it was designed.

Just spit-balling cause you peaked my interest. Now someone needs to try it! Little off topic.