5.7 Liter running Rough

[bbook83]

It is an inboard Competition Ski with a carburetor, engine serial # OK146780. This weekend I installed a new impeller. At start up, all was well with the impeller/water pump install, but the engine ran rough. I installed new plug wires, which I had on hand since last season when I installed new plugs and a distributor cap. While installing the wires, I noticed that plug #3 was loose in the hole, so I removed it and saw that the electrode was missing I replaced the plug, but it still runs rough, with a rhythmic hissing sound near #3, but no leakage detected at the plug threads. Is it possible that the missing pieces from the old plug have created problems with a valve at #3? Any other ideas?

 

[Scott Danforth]

do a compression test. also, you dont state what motor you are working on, other than a 5.7 in a ski boat. so that could be anything from the 70's to the 2000's

 

[alldodge]

Thanks for the serial number, a 1997 with TB5 ignition

It is possible the piece of the plug caused damage. Agree do a compression test

 

[bbook83]

Thanks for the thoughts. I will do a compression test. I was hoping to avoid it, as it will likely be even more challenging than the difficult replacement of all of the plugs, given the tight confines in this v-drive configuration, which basically requires me to stand on my head in the engine compartment. I know I am “preaching to the choir” on that point.

 

[Scott Danforth]

boats are sold on how shiny the decals are, how many cup holders, and how loud the stereo is, not on their ease of service.

many boats, you need to pull the motor to do routine maintenance.