I have an opportunity to buy a Lycoming 0-145-62, a 4-cylinder rated for 65 HP, and I'm wondering if this could go on a V-Max?  I'm guessing not, as it probably can't be bolted directly to the firewall, but for $500 minus carbs, seems like it would be a good deal if it worked. If not, I'm also considering a Rotax 582 or 532, instead of a VW.

It's 165 lbs. I'm not sure what the upper weight limit on the V-Max engine is.

Isn't that about what a VW weighs, or am I misinformed?

According to Great Plains (VW conversion specialists), VW conversions weigh 145 - 190 lbs. If I'm not mistaken, I'm pretty sure the V-Max is designed for a basic VW conversion (no starter), so it probably uses an engine on the lighter end of the scale.

Maybe someone on this forum who has a set of V-Max plans can check on the weight limits.

Another thing to consider is how you are going to mount the O-145. If a special mounting bracket is needed (which it probably is), then that's additional weight.

I got a Full VW down to 120# once. I removed everything that wasn't absolutely necessary, cut the flywheel down to just the center piece, and could have re-made that from aluminum for even lighter. Using stock jugs. BTW, I have a Stainless prop hub if anybody wants it. AND a couple half VW heads that aren't complete.