Merc 402 giving me fits of rage

[busterb]

Hey guys, X-mercboy here. (I lost my password and have a different email address!) Here is my dilemma. My 1977 merc 402 (40 hp) has had everything electrical and fuel related replaced twice, and still only fires on 1 cylinder. (Stator, switch box, trigger, plugs, wires, coils, wiring harness, stop switch, fuel pump, carb rebuild, hoses, etc.) My mechanic ( a personal buddy) thinks it may be the flywheel magnets to blame. Could this be true? If so, does anyone have a used flywheel for this motor? It seems to be pretty rare. Thanks!

 

[steelespike]

Re: Merc 402 giving me fits of rage

Are you working from a manual? Have you checked<br />compression?Have you tried switching coils etc from one cylinder to the other? (including plugs)<br />I doubt if it is magnets I had an old 15 merc that had one bad magnet It idled poorly and only<br />ran about 3/4 speed but ran on both cylinders.<br />You should be able to check magnets by simply putting a screwdriver on them they are pretty strong and should be equal.Is one plug wet,Does it<br />have spark Is there a timing adjust on your motor.<br />Have you tried squirting fuel mix into sparkplug holes and cranking?Run this by the guys at Johns Old Mercury Web Site at:www.pfs-ware.com They are always messing with Mercs someone must have some ideas. Im still not clear if no spark on one cylinder or just not burning the fuel.<br /> Keep trying.