On any other engine I'd agree, but on that engine I've seen at least 3 of them run without the chain for a long time before they were repaired or blew up. These are tough little engines. The recon i bought had an oil pump failure and ran for a month before it died. The PO that had it noticed it rattling loudly 4 weeks before it exploded the piston, but he was a kid and just drove it till it died. I know of two other stories similar. You're not doing the cylinder any favors that way, but they can run dry for a good bit it seems. Not many engines can pull that off. You may lose a little compression if you do it for a day, but it'll run for years if you fix the pump. No need to do an expensive rebuild if the pump fails and it still runs. One of the three i mentioned that lost their chain and rode it for a week fixed it and it still runs a year laterThat sucks. I would think the chain couldn't possibly have been off very long. Without the oil pump running the top end would lock up within seconds. Seems very odd it was still running.