1. I have an OS.91 4-stroke in mine. I cut into the tank area and lowered its floor to allow the fuel tank lines to center on the carb's intake. I had to recut a hole in the firewall, which allows the tank's neck to stick through below the stock hole. No problems with fuel spurting out, but I try to keep the throttle closed while fueling and only open it after putting the glow driver on and spinning with the "Sullivan".


2. Depends on your flying style, but if the servo can put out an honest 50 ounces they might be OK. I have Futaba coreless BB's, (non-metal gear).....putting out about 60 ounces. It's probably more important to upgrade to 4-40 push rods all the way around.

3. I tried to reinforce my firewall with some more glue and whereever I could get some triangle stock in. I added carbon fiber stripes to the top and bottom of the stabilizer's trailing edge, which really stiffens things up. I also glued in some triangle stock on the underneath side of the stabs.

4. Yes, I removed the covering in the front area from the gear block to the firewall and placed a layer of fiberglass cloth from the firewall around the gear block and back to the firewall on the other side. If you overlap the cloth over the front of the firewall you will also greatly reinforce that area too.

5. I have a Futaba 9C with an 8 channel receiver so I don’t use reversers.

6. Great Planes CA hinges work fine, just make sure you drill a hole in the center of each slot to allow THIN CA glue to flow in. I read recently where someone pushes several pins along the top and bottom of a CA hinge into the wing and control surface to create the glue channels. They removed the pins before gluing. It is also important to draw a line where the hinge will bend with a crayon or a grease pencil to keep glue out of that area. Only use enough glue to get adhesion. Don’t drench it.

7. I use a fuel Dot to aid in the fueling process.

Seems like a lot to do to get an ARF ready to fly, but I like you didn’t want any problems at the field! BTW, I forgot about a low growing tree near our field and flew the UCD through the top branches, breaking the prop and dropping it about 8-10 feet on its landing gear. The only damage was a slightly bent main gear, a small area of torn covering out at one tip, and a belly pan that popped off.