PCM 351 Dies and will not start after short runs on water

[JayhawkTs6m85]

Have a 1985 TS6m Comp with a PCM 351. I have struggled to get this boat to run since I bought it. previous owner didn't seem to have these problems. First weekend out engine would lose power as if fuel pump/filter was bad. Engine would start and idle and move at low RPMs but would bog down and die at high RMPs. After replacing both the fuel pump and filter the following weekend's run was worse. Engine stalled and would not restart. Stater would not turn and the only thing making noise was the solenoid. I have two batteries working in parallel and both checked out. Even tried hooking up to newer fully charged batteries to attempt to start with no result. After getting the boat on the trailer and returning home I was able to get the engine to turn and finally start with some effort. I replaced the solenoid with the hope that it would fix the problem and found once I did the boat started and ran while hooked to water hose and running in neutral without any problem. This brings us to this last weekend where the same problem occurred after a short run under power, the engine faltered, died and would not restart. No movement from starter and not sound from solenoid, I have yet to get it started again, the noise that was coming from the solenoid the first time is gone this time. There is only a light click followed by nothing. After it died the final time the only other change I noticed with the cowling was a light swizzling sound coming from the area of the starter and solenoid. Also main cable were quite hot to the touch. Batteries still show good. I would appreciate any help with this matter and thanks for taking the time read my lengthy post.

[BadgerW34]

Have a 1985 TS6m Comp with a PCM 351. I have struggled to get this boat to run since I bought it. previous owner didn't seem to have these problems. First weekend out engine would lose power as if fuel pump/filter was bad. Engine would start and idle and move at low RPMs but would bog down and die at high RMPs. After replacing both the fuel pump and filter the following weekend's run was worse. Engine stalled and would not restart. Stater would not turn and the only thing making noise was the solenoid. I have two batteries working in parallel and both checked out. Even tried hooking up to newer fully charged batteries to attempt to start with no result. After getting the boat on the trailer and returning home I was able to get the engine to turn and finally start with some effort. I replaced the solenoid with the hope that it would fix the problem and found once I did the boat started and ran while hooked to water hose and running in neutral without any problem. This brings us to this last weekend where the same problem occurred after a short run under power, the engine faltered, died and would not restart. No movement from starter and not sound from solenoid, I have yet to get it started again, the noise that was coming from the solenoid the first time is gone this time. There is only a light click followed by nothing. After it died the final time the only other change I noticed with the cowling was a light swizzling sound coming from the area of the starter and solenoid. Also main cable were quite hot to the touch. Batteries still show good. I would appreciate any help with this matter and thanks for taking the time read my lengthy post.

Did you by any chance throw a timing light on it? Backfiring at all? I would start there. Another simple check would be to pull the valve covers off and check the rocker assemblies for a cracked spring. It could be a carburetor issue also. Pull some plugs out and see if you are loading a cylinder up with fuel. Just some things that aren't too time consuming to look at. Hope these tips help.


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[michael hunter]

You probably have corroded battery cables . They can look fine on the outside but be corroded inside . You could do a voltage drop test or use a set of car jumpers to temporarily give a good ground and hot from battery to engine . You new guys need to put a city and state in your log in information help could be next door and nobody would know.

[JayhawkTs6m85]

Thanks for replying, I will look into those suggestions. There has been no back firing and I have not tried a timing light. I can only hope it is just a corrdoed cable . I will update my info as well. Thanks