Looked at a SEA FOX walk around (2000 21' volvo) with a neighbor. The engine looks to be a 4 cyl. (3.0?).The boat is setting on a decent trailer(2002). We checked oil and it looked clean. Hooked up some water and turned over the engine. The engine started after a few turns but shook pretty bad. It appears that only one mount exists on the front of the engine. Is this usual? Do mounts go bad or need replacing often? Anything in particular to look for with these engines? Would anyone have any opinions on the power or under power for this boat with this engine? Thanks in advance.