Saved this from the scrap guy, wondering what size and years will it fit on. All I have is the shroud and a couple small pieces. Would like to swap it out with a newer engine if possible. I believe it's a 3hp from 1959
I'm no expert but I've yet to come across one of these that isn't interchangeable among the small 1.75 & 3.5hp blocks - like the 6BS, 8B, and and later cousins like 60100s and 80100s. Don't know about the 90 thousands. Don't know about 5hp blocks.
On the other hand, this spec sheet indicates the cylinder bore for the six and eight are the same, whereas the 9 has the same size cylinder as the 13. Or maybe it's the stroke length that might be an indicator. Notice the stroke doesn't change significantly UNTIL the 13, at 2.438".
So I went out to check my stash of tillers and snow blowers and it turns out I've got a working tiller with a 4hp,a much newer motor though looks like it came from an edger. My wife and I stop by alot of garage sales and I buy every running tiller and snow blower that's cheap and stick them in my barn. Every one has been 25 bucks or maybe just a little more. If they don't run I usually don't buy them unless it's an hs40 or hs50. Got 5 running tiller and 2 non running snow blower. I'll go out one day after work this week and see if it will fit.