They were a good engine - at their time. The only reason I would want one on a SB is for originality. I have 2 on old Alroh edgers which I need to get around to. Since they are more of a display/classic piece than an everyday use item, it makes sense to keep original. Unfortunately, the heft of these make them somewhat unsuitable for our edges - I prefer to scoot around with a little Weedeater 26cc edger.
The issue is the peripherals. I know an old guy who bought an Ings edger brand new - hk25. Still uses it - or at least tries to. He found a NOS gasket set, cleaned it all up, with new governor seals. Then he had carby issues - stuffed needle and seat. Dripped fuel over the entire lawn and now has 'dollar spots' over half the lawn around the edges before he saw it. Solved that and now it has no spark.
For the price, a 127cc Briggs OHV is unbeatable on these - easy to start, parts availability and easy on the rails. For national pride, I simply couldn't put one of those little NX150 chinese engines on a SB45
By all means keep the old engine, but not something I would want to use. Problem for you is many others will feel the same way - I figure you are talking 500 set minimum order?
