could be several things here for sure - and a bit more info would be helpful
- like is this a raw water cooled engine and were you in sal****er? if so a
small head gasket leak that fouled a plug left to set for 3 days with salt
water in a cylinder can cause one hell of a problem! and was it knocking or
just missing?

"ram limn" wrote in message
news
motor seems to be locked after running with a miss...shut motor off three
days later starter will turn motor over...removed plugs and still will not
budge..removed starter and can not turn flywheel on front of engine