Ok i bought an 85 searay with a 407 Mercruiser in it the guy said the he had they boat for 4 years and ran it monthly but the last time he put it out it started fine but had a strange nose in it and it stalled he started it right back up started fine but still had that nose it stalled out agin now the motor is locked down! my question is this can something in the stern drive or that stuff back there cause the motor to not turn? I grew up in an auto repair shop so i know my way around a motor but the out drive is something i know NOTHING about everything on the motor looks fine pulled plugs checked oil checked anti freez it all looks really good! Went to drain the lube in the outdrive and it is black stink like its burnt but no water the magnent on the drain plug was coverd in metal shavings! can i get some advice!!!!!!