Johnson 150 BANGs

[eandkatthebeach]

Hi - I've got a 2001 Johnson 150 Ocean Pro, it was running great at the start of the season with new plugs in it, however on the way home from a fishing trip, the engine began to bang every so often, it looked as if I was hitting something or a cylinder was occasionally misfiring. It happened more often at higher rpms and also seemed to be a harder "miss" at higher rpms as well. I limped home for an hour at 8-9 mphs, toward the end of the trip I increased speed slowly and it ran fine - up to 4400 rpms / 24mph. I pulled the plugs and the port side lower plug was pretty well fouled(black wet soot) but there was a gap on the plug, so I replaced it. The others looked fine. Haven't restarted it - my question . Do you think that was the problem??? , and more importantly what do you think caused it? I don't have a fuel/water separator - no room under the deck - could that be it??

 

[oldgradywhite]

Re: Johnson 150 BANGs

knocking is never good. Do your hear any thing under the flywheel hitting. If your plug is that black and fouled first do a compression check then if thats good check your spark make sure its strong on that cylinder. If thats good you are flooding in that cylinder and you need are carb rebuild. If knocking persists after replacing that plug and you can't find reason for it any where else beside the block stop running the motor before you throw a rod.

 

[Chris1956]

Re: Johnson 150 BANGs

Is that banging when the motor pops out of gear? If so, that indicates an issue in the gearcase,