18 Seacraft 150 VMax question

[Gaffer]

I’m going to look at a 1987 18 Seacraft that has a 2002 Yamaha 150 VMax 2 Stroke. Specs say that the VMax weighs 418 pounds. Is that engine too heavy for the hull? Transom looks to be original 20”. I’d be looking to keep on a mooring. Any idea of what mpg I would be getting at cruise. I’ve read that the vmax is a bit thirsty but a very solid engine. Thoughts?