Can't remember the title, but a gang of boys get into various misadventures. They build a flying saucer and fly it over the town. And they also build a lake monster. Can't remember much else about it. It was likely printed in the early 70's.

Thanks,
John

Adirondack Kids??

Sorry, that doesn't look like the one I remember. As far as I know there was only one book by this author, because I wanted to read more of the same but there wasn't any.

Thanks for replying though,
John

I believe I found it today with the assistance of some Barnes and Noble employees. It's called The Mad Scientists' Club:

Mad Scientists' Club: The Official Website