This is a responce I provided some months ago.

Roy gave you an outstanding responce RC. I desided to respond also because of some significant differences between what Roy did and experienced and what I did and experienced. I did experience a lot of what Roy did.
I built 2 of these, one with the original Kyosho color schemes and one brietling, so there was quite a bit of time between the production of the planes. I powered one with a ST.45 ABC (pits muffler) and one with a webra.40 (pits muffler). They both perform the same. Flight characteristics are good, they have no ugly tendicies and don't snap under any conditions unless told to. They are extremely nice to land and takeoff. Both airplanes came out with the CGs at 3 and 3/8s without adding any lead and with the battery packs just over the front of the wing. 3&3/8s is the aft limit per the addendum as I recall. I have about a 150 flights on the first one and just a few on the second
Building:
Build per the addendum, especially control throws.
I used almost all the hardware that came with the plane even though it was of poor quality. I haven't had a failure of it in 150 flights but I would still recommend throwing it away. I'm just not smart enough to do that. I did throw away the shrink sleaving for the control rods and instead used flat cord and ca. I also chucked the bolts intended for the axels and replaced them with dubro axels. Threaded bolts in bending is a fundamental no no.
I hate the vacumn formed plastic for the wheel pants and cowl. Don't put the wheel pants on untill you have a good solid feel for the plane and can grease it in every time. Even then they probably won't last long. I used 9 screws to attach the cowl. 3 on top, 2 on each side and 2 on the bottom. The cowl is still cracking out at the attachments after only 150 flights.
The engines are completely enclosed in the cowl so I cut a one inch on a side triangle out of the cheek behind the engine head about .5 inch forward of the trailing enge of the cowl. I don't have any heat problems but I have heard of others who had but had not made this change.
Both planes came out between 5.25 and 5.5 lbs.
Landing gear mounting to the fuselage has not been a problem.
I a got good quality covering job on both. I mounted the canopy with 4 wood screws.
Flight:
I have just slightly more control throw than the addendum calls for and I'm very happy the way it flies. I haven't been able to get it to do tumble maneuvers as yet but that may be me. Flat spins aren't quite as flat as I would like. It will spin in either direction from upright or inverted without the need for aileron input. I like that. I also like the fact that it will stop snap maneuvers the instant I neutralize the controls. I don't have use a big handful of rudder to stop the rotation. This I'm sure is do to the very light wing.
On my first flights I had about 2 inches of rudder throw instead of the called for 1.25 inches. This was a mistake. The rudder will start stalling at about 1.5 inches. This results in pitching to the gear and in spins with aileron it will actually cause rotation in the oposite direction. I could actually roll the plane inverted, apply full rudder only and do an outside loop. The heading changed of course but it would complete the loop. Knife edge maneuvers are good with only a little rudder input.
Hope this helps.