Hello SDcottm355

As far as I can tell, Tecumseh did what Briggs did at the time.
[Brigg's 6 series was made to be 2, 2 1/4 and 2 1/2 hp.]

They used the same short block, but changed governor and carburetor settings.
They also changed things like fuel tank size.

The Kirby Mechanics Handbook (second link) supports this view.

https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/84697/re-kirby-hk25-and-hk30-engines.html
https://www.outdoorking-forum.com.au/forum/u...y-4-stroke-mechanics-handbook-c1963.html

From parts lists I can't say I have found any substantive difference in
these models. Today, parts seem to be treated as interchangeable.

Cheers
--------------------------
Jack