295cc needs replaced or repaired looking for recommendations?

[ezgorg1]

I am new to golf carts and we bought a 2003 EZGO TXT with a 295cc motor. We got it out this spring and did not check the oil before it was ran around town. Wife was about to go again and it started making a funny noise and then stopped. Had a local mechanic that has tuned golf carts stop by and he believe the cam is not locked up however the motor will no longer turn over. I am on the fence about trying to repair it as it sounds like this engine is getting harder and harder to get parts for. I am looking at replacements however what I am seeing it is a huge step up in CC and I am not looking for that as we are getting an ATV to accomplish the off trail fun.
Has anyone had a locked motor and rebuilt it and had no issues for years after?
Is there a non-big block replacement options?