wot boggs out- merc 850 serial # 4369341 what year is this please

[captin 420]

Wot my mere boggs out. I checked the fuel lines and rebuilt the carbs and fuel pump. Mechanic said exhaust sucking air causing air mixture to change? I don't know but he said the seal is bad on the lower crank causing this. What can I do?

 

[The Marine Doctor]

Re: wot boggs out- merc 850 serial # 4369341 what year is this please

If you have done carbs ect...run the engine at 25:1 see if this makes a difference...if it cleans it up...then engine has a leaking seal or is worn out <br /><br />Not the greatest news, but you came here for answers.<br /><br />OR check the timing.<br /><br />TMD

 

[captin 420]

Re: wot boggs out- merc 850 serial # 4369341 what year is this please

so does this mean I need to rebuild the top end. The motor runs fine on the dyno but has a problem in the ocean. I'm going to leave it hooked up to my trailer and in the water to see if it produces the same effect as the dyno. When it's on the dyno it gets up to 5500 rpms. So if it produces the same effect I guess the seal is bad. I rebuilt everything else and took it to a mechanic, and that is what he said. So if the seal is bad what should I do? And is it worth to rebuild? Do you also know of any good merc mechanics in the San Diego, California- North county-Oceanside,vista, escondido,etc...