Hi
I am well along with a flat top Max project for which I had a Global engine but I have since sold that engine to get the money to buy an N-3 Pup, but I might have enough left over to buy a 447 for the flat top Max.  I have not ventured into two cycle land and other than knowing that the 447 is one of the preferred engines for Maxes, I know nothing.  Could you folks enlighten me as to what gear box is most commonly used with Maxes and prop info too would be appreciated.  Thank you very much for your help.
Kim Brown
New Hampshire

Generally a "B" gearbox is used for the 447.....
If you buy an engine without a gearbox, you really need to check to see if it's a "-8" engine.
It will have 8 holes in the crankcase for mounting the gearbox, surrounding the crankshaft.
There should be a picture around here somewhere.

Some have used belt redrives, but you still need a way of mounting the redrive.

You need a 2.58 to 1 ratio gearbox....B type is most common.  https://www.leadingedgeairfoil.....x-type-b-2-58-1.html

You may find some old engines with A type gearboxes but you should avoid them:  http://www.ultralightnews.ca/gearboxes/rotax-adrive.html

A 62x34 prop will work well.  Other choices are shown here:  http://www.tn-prop.com/PropRecommend.html

Yes, Charlie is correct.  As for the engine, 503, or 447 is a pretty good choice. Even a 377, as it can be converted to 447.

The demon prop over here is a hand made to order 60X42 Newton. It is a beautiful prop on a 447 with lots of go.

Quoted from PUFF

Yes, Charlie is correct.  As for the engine, 503, or 447 is a pretty good choice. Even a 377, as it can be converted to 447.

How do you do this? Just put the bigger jugs and pistons on it?

The difference between 377 and 447 is bore/piston size.

I converted  my 377 Prov 8 to 447 Prov 8.  Then sold it.