bri460

hey need some help having 2 problems 1, every once in a while after longer periods of time running the motor, it will just die out .i have to let it cool down after about a half hour it will fire back up but running real bad almost like its running on 7 cylinders. there closed cooling systems so there running about 165 max,i have replaced the plugs ,caps wires rotor.second problem is today i was out there and the motor died so spent about half hour , trying to get it running and i get it fired up, but first runs like above and i hear a loud banging noise, shut that motor down and just run the other back to the dock, start it up and hear the noise again hard to pin point where its comming from. so i raise the out drive up and it stops at the time it was in neutral.now is it possible that the starter gear stayed engaged because i did crank it over for a long period and after a while you hear it miss the flywheel or is it in the trans maybe misaligned motor to the trans or the u joint going to the trans? also took the boat for a ride afer all this and did not hear the noise again forgot to mention that there 1996 454/330 and trs outdrives

Chris Sunkin

On the motor problem, you need to look at the plugs and do at least a compression test. If it's been a while, I would replace the basic ignition parts- plugs, wires, cap & rotor. Just dying and then running rough on startup could be fuel contamination. If you have separatrors, check them for water. Water in carbs usually won't find its own way out so I'd at least open them up and clean them out- remove the needle and seat- junk can collect there & cause problems.

On your drives, I'd be a little concerned about the u-joints if they haven't been replaced in a while. But that's probably not your problem. Unless something came loose on the mounts, neither is misalignment. If your starter hung up, you'd know it- it would make all sorts of racket and eventually either destroy the starter or the ring gear- or both. Your only real choice is to check everything, then try to make it happen again if you don't find it. Internal engine noises NEVER go away- they just get worse. On idea- cracked flexplates can make one hell of a racket- sometimes just like a bad rod, sometimes more high-pitched.

Boats need inspection and maintenance more like airplanes and less like automobiles.