On closer inspection of your motor picture, it appears to be more of a 32 sized motor - 4250 or so I imagine. What really surprises me is that it redlines at 700W if it can take 6s! That is quite unusual for outrunners. With a low KV it can be done evidently.

On these birds with trike gear, we are usually aiming at high rpm on smaller props compared to the typical electric wisdom. The idea is to use higher KV motors that will get a smaller prop up to speed and produce good power. An identical motor with a higher KV of say around 800 would have delivered the extra Watts one might be looking for and get it into the ~900W range. 150 W/lb or more is nice on a classic for excellent performance. So you'd be aiming for 750-800W at full throttle. Your setup will be similar to the performance of a typical early 80's 40 size engine like a K&B 40 rather than a modern 46.

That said, your model will fly just fine, it just won't be quite the performer that it could be. If you decide to retrofit another motor later for more performance, you might also want to consider mounting the motor with the typical X-mount to the firewall. This is generally a more solid solution on these power ratings and it will also keep the lines of the plane cleaner. The prop adapter mounts to the can of the motor rather than using the shaft off the back. Some simple 3/8" hardwood dowels or aluminum standoffs can put the motor at the desired distance from the FW.

Enjoy!

David