Allen Sutphin

The Polini 303 engine that I tried to use was just too light for the CG. Just bought a rebuilt 503 to install. May be old tech, but still reliable as can be.

From what I am told, the 3203 (65) is a little overrated and the 3202 (55) is a little underrated on horsepower. The Gen 4 Jabiru 2200 (new) is also an option along with a couple more 4 strokes.

Hirth is close to pricing themselves out of the market. They have went up a few thousand dollars in the last couple years.

Hirth engines are pretty good. The big difference is that there is more info out there on Rotax and how to run them, than there is for the Hirth. Call Matt Dandar at recpower.com and talk to him.

Jim, the model 4 kit you have that I'd built was 9850 back in the day. With cowling and everything minus engine and prop. I think '91.

Getting a replacement AWC is pretty easy if it's legally registered already.

Not an older model, it's the "classic" model. All Model 1. 2 and 3's are classic's along with the Avid series.

The days of the 10-15K Avid/Foxes are over for now! When I started (yes, they had airplanes back then) it was $50 per horsepower and $5K per seat. Now its over $200 per horsepower and almost $20K a seat.

Because most only plan to build once and are not too concerned about replacement or just don't think ahead. Repeat offenders, oops, I mean repeat builders know the little tips and tricks of the game. 

Glad you got it out. I've got the same problem except mine was welded in. Probably 3 days of cussing, 2 boxes of band-aides, and maybe!

Looking for a Hirth F-23 engine. Prefer pull start, carbs and redrive. But will consider any F-23. Thanks!

Might take a little bit to find one. A full swivel one like the RV series and several others is easy to make and requires less modifications and weight.  It can be built into the engine mount fairly easy. A little backyard engineering and a few materials and you have it. Diff braking is a must.

Weighed mine today, minus engine and prop. Came in at 164 lbs, including engine mount and inst panel. Leaves me 90 lbs for engine and prop. The Hirth F-23 supposed to weigh 74 lbs with redrive and exhaust so it will be close or a couple pounds over the 254 limit. But around here the FAA isn't hiding in the bushes and I fly out of a hayfield. 

Almost the same bird, and nice looking. Getting hard to find now. About all the 2nd seat was good for was extra storage. I think I'll be very close to Pt 103 wt. 

Thanks!

Well, bird got its new skin the other day. Not too bad for the hillbilly "skunk works". Now, time to start thinking about the FWF.

Make a new sling, buy some Wally world chair cushions or lounge chair cushions. As for the sling, get a small canvas tarp and a grommet kit. Anything can be made. In those "immortal words", "around here, if you want something, you gotta build it". Never truer in out of production aircraft.

I talked to Dave Snell, engineer for Kitfox, about the thrust line on my Fox. He told me to just center the thrust line and then use rudder or a trim tab. It really messes things up in a full cowling when you offset the thrust line 4 or 5 degrees L or R depending on engine.

Don't have a hillbilly clue just yet. Would like to use a Hirth F-23 if weight will allow it. Still going to try Pt 103. Did register it as a Mountain Cat and was issued a N number and registration card. So the adventure begins!

Did finally get the painting done after covering. Now start planning on locating an engine.

Unless one is familar with aircraft construction in general and methods used, I always steer one towards a kit that is still in business and producing kits. The older Avid/Foxes are great aircraft and fairly easy building, and this group is a truckload of knowledge. The new Kitplanes buyer's guide will tell you the general spec's on current kits that are available. There are a few Avid/Fox kits out there that are not completed or finished, but you have to make sure all parts are there and some paperwork is included. Before you decide on a certain kit, #1 is to decide what you want to do with that aircraft. Cross country, STOL flying, local flying, etc. Then find a kit that meets your goal. And don't look for one that does everything, it doesn't exist! 

If more than 10-15 degrees is needed for trim then something is wrong. Rigging is off, CG is off, etc.  My Kitfox had no published deflection limits for the trim tab, just the elevator.

After studying the fuselage for a while, It's pretty darn close to a single seat Avid Flyer. Mine has more room, head and leg, than my Kitfox did. I know there was one or two that were going to make their Avid/Fox a single seater. Since they were all grown from the same seed, it stands to reason that they would be close.

Just learned that a guy named Al Large owns Skyraider. He said he does have a few parts for sale. Would like to see all of the old classics revived. Somewhere in the northwest US.

I would also check the shock mounts between the engine and plate. My Fox vibrated pretty bad with a Hirth 3202 until I replaced the rubber mounts. This can be done after checking what Jim said. Normally with bad mounts, the vibrations will increase with RPM. Mine was so bad you couldn't read the gages.