A friend's brother has one of these as a home backup generator and cannot find any information on it. It's a propane/NG model with serial number E4499A/002. Does anyone know what model engine would be installed in one of these, just as a starting point?
It is a strange Isuzu engine made by Isuzu Hindustan and nothing like it was made in the USA. Caterpillar had parts last time I worked on one but they were never popular. One broke a timing belt and lunched the top end, the other one ran a zillion hours and the owner sold and moved away, I assume the new owners put something better in.
I was able to find some information on that 4ZB1 after my initial post. It sounds like they'll try to get it going in the interim (whole-house solar system failed) and replace it with a Generac or Onan eventually. Dealing with oddball orphan equipment like that long-term isn't worth the effort for a mediocre genset. At this point I'm just hoping to find a parts manual for him.
Generac or Onan don't make anything worth considering. Kohler is where it is at if you want air cooled small but if you want something comparable, be prepared to shell out over $20k nowadays. Diesels are easier to find.