tcj

Did you put a stand on the scale to raise the tail to level?  if so did you subtract tha weight from the tail wheel weight?
 
I would carefully remeasure all 3 wheel arms.  I seem to remember some 4s with grove gear having a negative main wheel arm.  For what its worth, my classic 4 tail wheel arm is 158.5 inches.
 
If you still have an aft cg problem then start removing items unnecessary for flight one by one.  Throw them up in the air and if they come back down, dot not put them back on the plane.  Seriously, there has to be one heavy kitfox. 

Strut fairing is the one add on that gained me more performance than it's weight penalty cost me.  I haven't timed the climb rate to be sure but it does seem to have increased.  The cruise speed at 5800 rpm went from 75 to 85 mph and the power off glide improved significantly too.

Weight gets added one ounce at a time throughout the building and then the "Improving it" phases.
 
The original kitfox classic 4 sales brochure lists the empty weights as 580 with a 912, 560 with a 582, and 495 with a 503.
 
The 495 with the 503 required no polyspray, no wing tanks, no strut fairing, no false ribs, etc.  I built mine pretty bare bones but did install, two wing tanks, top and bottom false ribs.  I put three cross coats of polyspray on the top surfaces but  only two cross coats on the bottom of the fuselage and bottoms of the wings.  It weighed in empty at 547.
 
Seven years later it weighs 573.  26 pounds gained one ounce at a time.  Actually, 12 pounds was all at once when I added PVC wing strut fairing.

Take off
http://vimeo.com/21117189
 
Landing
http://vimeo.com/12693781

Mine seems to like 6000 best for cruise at 85 mph true airspeed.  It is a Classic 4 kitfox with a 503.  I get a lot of caustic comments about my 503 but I love it.  The installation was just plug and play.  It hits 6700 wide open straight and level.  6250 full power climb at 60 mph 800 feet per minute solo.  The airplane is very sensitive to weight and density altitude, but the best feature is it is affordable for me.

Wheel seal part numbers.  I've kept my old part boxes.
the originals that came with the kit   CR services 8763
 
I have replaced over the years with
National 471633  it has the dementions on the box  0.875 x 1.577 x 0.250
Car quest  471633
SKF 8763 
 
Note from the Moderator...When you moved your mouse down to start typing in the box you accidently clicked the little S icon with the line through it. It's just another type of font you can do. I've done it a time or two myself.

I don't know why my reply has a line through all of it.  Can you read it?
 
Wheel seal part numbers from old boxes I have.
 
Originals that came with my kit  CR services 8763
I have replaced over the years with
National 471633  it has the dementions on the box  0.875 x 1.577 x 0.250
Car Quest 471633
SKF 8763

Another check to check wings level to slip/skid bubble centered (or off a bit).  Stretch a string from wing tip to wing tip above the wings.  Jack one wheel up a little or let air out of one tire to level that string.  Where the bubble is now is wings level flight. 

A couple pictures attached.

I ordered a couple snap vents a while back and the 2" hole instructions looked too small so I tried it in a scrap piece of Lexan.  I tried hard enough to fit one in that hole that it was about to become a broke snap vent.  I finally gave up and sent them back and exchanged them for Vista vents.

If you fog the engine and use the extension tube on the spray nozzel, hold on to it.  I didn't like being that close to the spinning prop so fogged mine with the engine not running.  That little red tube shot right into the carb and down into the crankcase.  I could see it but when I touched it with the end of my needle nose pliers it fell down underneath the crankshaft.  Had to remove the cylinder to get it out.

I have the Jacober sparrow needles on a dual carb 503. At full counter clock wise and 4000 RPM ststic the mixture is very rich. My engine smooths out a little on the first turn clock wise. I most often leave it at three turns clockwise where the engine is real smooth and EGTs are about 1150.

Starting from full open (Full counter clock wise) you should see the engine smooth out and EGTs rise with each turn clock wise. I seem to only need to adjust them different from three turns when the air temperature changes with the seasons. I don't think I have ever needed more than one turn either way from three.

At 6000 in level curise my egts run 1175-1200. If I load the prop just a little the EGts drop. Thus, dropping RPM to 5500 and maintaing level flight the EGTs drop.

Ed, in answer to your question. The super-constellation was a lockheed L-1049. There was a military version of the constellation labeled Lockheed C-69. Dc-9, thats a Douglass aircraft Jet.

Ed, yes the flaperons are included in the wing square footage published by kitfox.

In 2001 I ordered materials from skystar to build a new wing for a Classic IV. This note was included with the instructions.

"In September 1997 Skystar started supplying longer stronger spar incerts for the wings on the model 3, 4-1050, 4-1200, XL, Speedster, Classic IV, and 1200 lb gross weight Vixens (pre serries 5)"

It cautioned you to mark your original builder's manual spar incert instructions with an X and use new instructions included for installing the heavier incerts.

I don't know for sure but suspect the heavier incert was part of the increase to 1550 lb maximum gross on the later "Big" Kitfoxes.

tree top, my kitfox kit turned out like your photos show. One front spar attach hole is about 1/4 inch behind the center line. I fold and trailer for each flight and it doens't seem to be a problem. I had to run a reamer through it with the spar in place over the carry through tube lug to get the pin to slide in, because the hole in the reinforcement was drilled before installation and perpindicular to the attach fotting. Did that make any since?

The lugs on the carry through tube were spaced exactly to the correct distance ao I called the factory...the old skystar now defunct factory not the current one...and the guy told me to drill the spar where it is. That was bad information. After I drilled the first front spar I measured the spar ends and they were spaced a 1/4 inch to wide.

Then I placed the number one rid in position and it was a 1/4 too short. I could easily hold the spars tight to the ends of that rib with very little pressure. I checked the other wing and it did the same thing so I Put the number one rib in place and put a bungee around the spars to hold them tight to the rib before I drilled that one.

Just make sure when you epoxy the number one rib to the spars that you force a solid bead of epoxy into the space between the rib and spar. If there is any in your case that is. I epoxied the number one ribs to the spars with the wings installed on the fuselage and let them set up before removing them so as not to force the spars out of alignment with the fuselage lugs.

There used to be a guy on the matronics kitfox list that had no electric starter, just a rope pull starter on his kitfox. He had the gear box clutch too. The rope starter handle was routed out the left side of the coweling. He had to start it standing outside the plane. If he was held up wating for his turn too long at the runway he would shut it off. When his turn came he would get out and pull the rope.

I have a 503 in my Classic four kitfox. With only 52 HP my rate of climb is very sensitive to weight am always considering removing the electric starter and battery and installing a rope pull.

If your inspector asks why no electric starter tell them light weight is important with these planes.

The Kitfox factory ones are .090 in.

I saw one that was made by making the 90 degree bends in a sheet of lexan with a sheet metal brake.

My Kitfox Classic 4 manual from 1994 says: Use 220 grit or Red Scotch Bright to rough up a 1.5 inch band where the structural adhesive will contact the spars when the ribs are glued in place.

I used 240 grit emeroy cloth, I think because I couldn't find any 220 grit.