Johnson works on land but not sea

[akukulya]

I have an 81 35hp johnson seahorse which starts up on land and runs smooth in and out of gear. However, once in the water she starts but then chokes and sputters out. i can restart her several times and it dies quicker each time. It's not an overheating issue since the impeller and thermostat have just been replaced. My battery did lose juice quicker then it should which may or may not be related. any ideas? perhaps it needs to be tested under a load prop? i'd greatly appreciate any and all help. Thanks.

 

[JB]

Re: Johnson works on land but not sea

Hi, Pescadora.<br /><br />An outboard with no load on it is an amazingly good faker. Your engine can start and sound fine on one cylinder with no load. It can also seem fine using only a fraction of the fuel required to do useful work.<br /><br />Also, outboards often behave differently with no exhaust back pressure from being in the water.<br /><br />I suspect that your engine starves for fuel when under load and/or when there is back pressure on the exhaust.<br /><br />I would investigate the fuel system for air leaks, tank venting, weak fuel pump and partially plugged jets in the carb.<br /><br />Good luck.

 

[akukulya]

Re: Johnson works on land but not sea

Thanks JB,<br /><br />I have put in a new fuel pump, and have investigated the tank and and valve connections from the tank to the engine and all are ok. maybe gummed up carb...i guess that is next unless there is something I am missing. Thanks again and I'll check in when i get somewhere.