[Gompers]

I don't think you can tell just from that. Best tell from that photo is the air cleaner. Most of the round ones I've seen are on series IIs, and most of the series I's I've seen have square ones.

I currently own 2 series IIs with square ones, and 1 series II with a round one. Have a series I lined up with a square one.

Best way to know for sure, aside from the serial/spec number of the engine, is to look for the block off plate for the oil filter on the front right of the engine (technically it's the left rear as the engine is mounted backwards in CCs). It will be behind the PTO. That's not really definitive either, but it's about as good as you can get without digging deep.

With the KT-17, it's all about maintenance. A well maintained one should go 1200-1400 hours, or maybe even more.

If it's been abused, it can poop out at any time I guess.