Kitfox 4 XL

[Abgreen]

I'm looking at a XL it's equip twitch a 503 from factory and as far as I can tell it was manufactured with a smaller tail then the classic 4. My question is how would the control be affected if 80hp Rotax 618 or 912 was hung on the front. Will gear support it motor mount needs to be changed obviously any other changes needed to make it right thanks. Avery

[avidflyer]

Just looked in an older LEAF catalog, and the bare 618 engine is actually 1 pound lighter than the 503. Of course you would gain weight from the radiator and coolant with the 618 but not very much really. 5-10 lbs?? I think the same motor mount might work for both as well if you used the bottom mounting bolts. The 912 is a different ball game though, different mount and a good bit more weight. Jim Chuk

[DesertFox4]

Avery- first welcome.

Many of the early Kitfox models had less tail (vertical stabilizer and rudder) than the model 4-1200's or the Classic model 4's. My first Kitfox was a model 3 (1050 lbs gross weight) and it had a 912 80 hp. Rotax . It was a great performer. Having a larger tail/rudder is better for crosswind conditions and recovers from spins with a little more authority.
There weren't many XL's sold that I know of. They sounded like fun aircraft though.

[Av8r3400]

Wow. I can honestly say I've never heard of a IV-XL before.

How do these differ from the Lite²?

[t j]

In 1994 I saw an article in a magazine about the new Kitfox XL. A complete Kit, everything, as in all the pieces to build a complete airplane, powered by the 52 horse power 503, maximum gross weight of 1050, and was $14,995. I wanted one! Flew over to the factory to take a ride in their XL demonstrator. I was really disappointed when they told me they had shipped the XL demonstrator to France and were no longer producing the XL Kits.

But....the XL was actually just a stripped down model 4 and they were bringing back the model 4 renamed the Classic 4 and would sell me one with a 503 engine for the same price as the XL. Patrick Rediker gave me a ride in that famous florescent greenish yellow and red Model 4 speedster...it was quite impressive.

I built my Classic 4 with the 503. With that engine there is a power limitation on the maximum gross weight of 1050. I've since heard hearsay that the XL was actually a model 3 fuselage with the rest of the components being model 4. I don't know what the true story is, as I have never seen an XL in person to check.

I have no doubt you could put a 912 on the XL but the question I have never had answered is...was the max gross weight of 1050 on the XL a power or airframe limitation??

[t j]

Here it is, Sport pilot September 1993.

[HighWing]

TJ got it right. Attached are the pages from a 1993 Sales Brochure. Sorry about the orientation - tried to correct it.

[t j]

Thanks for posting those Lowell. I printed it out for my kitfox files. It lists the XL max gross weight as 950. I can't remember where I got the 1050 max for the XL...probably thought that because the factory guy told me the classic 4 was exactly the same as the XL. The Classic 4 has the power limitation on Gross weight of 1050 with the 503 engine.

Looking at the prices I guess I got a fair deal of a complete package for $14,995. It included everything including instruments, and poly fibre materials through Polyspray. I had to buy the polytone was all.

Abgreen, max gross weight of 950 would be a deal breaker for a 912 in my mind. You probably should check the paperwork on that XL for sale to see what it actually is.

[Av8r3400]

How do these differ from the Lite²?

maybe the "XL" was a light version of the IV-1050? The light version of the IV-1200 was the Lite².

Love to know he whole story.

[SkyPirate]

Just evolution of our favorite flying machine :)

[av8rps]

Yeah, I remember the XL. Both Avid Aircraft and Kitfox were attempting to "Go back to the future" with inexpensive, lightweight 503 powered versions of their Model 4's.

Unfortunately neither the Avid Bandit or the Kitfox XL ever really went anywhere success-wise, as most that priced them out just decided to spend a bit more and get the regular Model 4, or Mark 4.

I think Larry is right in thinking the XL was essentially just a remade Model 4-1050. They were drastically trying to get the empty weight down so it would fly well with the less expensive, but lower powered Rotax 503. So in my opinion, I believe the gross weight being derated from 1050 to 950 was only due to the lower powered engine not being able to handle the higher gross weight as well.

However, I'm pretty certain that at the time if you called Kitfox and asked them if it was ok to up the gross on your XL to 1050, they would probably agree as long as you were using a 582 vs a 503.

[tommg13780]

I have an XL that was manufactured in 1997. The original factory invoice describes this one as a classic 4-1200. It has the old style header fuel tank forward of the instrument panel with no wing tanks. The builder used it as an ultralight trainer but only flew it about 100 hours until 2002. As I understand it the XL later was renamed Lite squared in hopes of getting better sales. I put about 50 hours on this airplane and the 503 engine just doesn't have enough suds to do much more pattern work at 538# empty weight. If anyone's interested it needs a new home.

[t j]

When I was building my Classic 4 with a 503 engine I got a lot of caustic remarks from other members on the old kitfox List. One old Fantom Fighter pilot said it wouldn't have enough power to even fly.

It is low powered. Max gross weight is 1050 due to the power limitation. I don't take fat boys...or girls...as passengers on hot days but it has taught me how to fly, not just push in the throttle and hang on.;) The best feature is that it is affordable for me to fly.:)

[SkyPirate]

That's what counts TJ 👍. My very first , my own was an MX quicksilver with a 377 on it, that was back in the 1900's. :) 30 planes later I'm in a Kitfox again but a 5 outback, my last Kitfox was a model 2

[HighWing]

maybe the "XL" was a light version of the IV-1050? The light version of the IV-1200 was the Lite².

Love to know he whole story.

Attached is a photo of a Kitfox Lite taken in 2003 at the fly-in I used to host. I recall the talk back then how Kitfox wanted to have a typically configured "Legal" Ultralight. Talk then was regarding weight and how many ultralight aircraft at that time were strictly legal as to all aspects of the regulation. This one was.

A lot of the models were directed by market forces - fitting a niche. The Lite satisfied the requirements of an ultralight aircraft, but there didn't seem to be enough trained pilots who wanted or needed the Lite concept.


There arose the issue of training. Being single place, this airplane (Ultralight) was not capable of being used for training. As I recall, this was the reason for the development of the Lite 2. Someone with experience in ultralights needs to chime in here, but my understanding is that there were provisions for training ultralights that exceeded some of the regulation's specifications for single place Ultralights. The Lite 2 was to fit this need.


I have a neighbor with a lite 2 with a Jabaru 2200. He didn't build it, so don't know what he knows about the history, but I will talk to him and report back if there is anything specific to the question.

[mr bill]

Lite 2 is a Kitfox lV-1200 with provision for nosewheel or tailwheel and a 503 cc engine according to John Mc B.

[av8rps]

TJ,

I'm sure by now you've learned not to let the naysayers get to you too much. I think a 503 Kitfox would be a super fun, super simple, and yet a practical recreational airplane. And ask any of the ultralight crowd, they regarded the 503 as one of Rotaxes best engines. So it should make for a really nice airframe/engine combination.

I never had a chance to fly the Kitfox 503 XL, but I did fly Avid's 503 Bandit. It was a hoot to fly, only weighing 425 lbs empty. In fact, at the 1993 Avid Fly in it won the takeoff contest, but the factory removed it from the competition so a builder/owner could win the award instead.

Ironically, when Avid put their 503 Bandit, their 912ul Mark 4, and their 0320 lycoming powered Magnum all on floats and flew them to Seattle for a weekend of seaplane fun (and a great magazine article), everyone in the group was fighting over who got to fly the 503 Bandit as it was the most spritely and fun to fly on floats. So for those that think a 503 powered Kitfox (or Avid) is so underpowered it can hardly fly, they obviously know little to nothing about these airplanes.

Another tidbit...weren't the first Kitfoxes all 503 powered? Seems to me they set the stage for the Kitfox to be known as an amazing STOL airplane at the time. So they were hardly underpowered.

And the original Avid Prototype (grandfather of all of our modern versions we enjoy today) with only a stinkin' little 40+ hp Cuyuna 430cc 2 stroke (from a Scorpion snowmobile) will take off shorter and outclimb many of it's more modern Avid and Kitfox derivatives. They advertised it at 1460 fpm solo, and it would do AT LEAST that for climb on a standard day. It also made an EXCELLENT floatplane, with performance very comparable to a Super Cub, even with two people. I can say all that as I flew that particular airplane for about 700 hours, with 300 of those hours on a set of straight floats. And I still own that airplane today. It truly is a great performing airplane. What was it's secret? Lightweight...360 lbs empty. No electric, 72 inch 2 blade prop with a 3 to 1 reduction, etc. Best description...no frills.

I know an XL is a bit heavier than the early airplanes described above, but if built bare - bones they could be kept in the low 400 lb EW range, and consequently would perform very well. Unfortunately many ended up being built much heavier due to adding options like bigger fuel tanks, electric starters, full panels, carpeting, pretty paint, etc, etc. So to get the performance needed they needed more power, so airplanes that should have been 503 XL's ended up being 582 Model 4's. So the XL part just faded away :(


When I was building my Classic 4 with a 503 engine I got a lot of caustic remarks from other members on the old kitfox List. One old Fantom Fighter pilot said it wouldn't have enough power to even fly.

It is low powered. Max gross weight is 1050 due to the power limitation. I don't take fat boys...or girls...as passengers on hot days but it has taught me how to fly, not just push in the throttle and hang on.;) The best feature is that it is affordable for me to fly.:)

[Abgreen]

Wow guys looks like I stsrted good conversation topic here so I thank you all for your time and added information. Since I started this thread I have run across a model-2 forsale and find myself in similar situation some people say stay away from any model prior to the model 4 due to supposedly unstable airframe and known squirleness ground characteristics. So I. Just trying to find out what exactly makes a classic 4 better in the air /ground. Is it wing placement tail size etc. it is windy where I live but I have lots of tail wheel time and wind doesn't bother me I'm just trying to get educated on the short Cummings of these early kits. Thanks in advance for all the forth cumming advice. Abgreen

[Dr. Dave]

I have an XL that was manufactured in 1997. The original factory invoice describes this one as a classic 4-1200. It has the old style header fuel tank forward of the instrument panel with no wing tanks. The builder used it as an ultralight trainer but only flew it about 100 hours until 2002. As I understand it the XL later was renamed Lite squared in hopes of getting better sales. I put about 50 hours on this airplane and the 503 engine just doesn't have enough suds to do much more pattern work at 538# empty weight. If anyone's interested it needs a new home.

I've been shopping for just such a plane. I found one on Barnstormer's that I plan to pick up this weekend. I'm curious how much you would ask for yours. I'm also curious about what kind of performance I should expect from it (stall speeds, climb rate, ground roll, fuel burn, etc.). I've been flying with the 503 on Challengers and Quicksilvers for years, but I now need a folding wing I can hangar in a trailer. Any info. you can give me on this plane would be greatly appreciated. Thanks in advance.