2000 Honda 40 runs perfectly for 20 minutes and then shuts off.

[Really?]

My 2000 Honda 40 runs perfectly for 20 minutes and then shuts off. No sputtering, just like "the lights go out". I had the carbs cleaned professionally last year and have replaced the impeller and the pulser coil. It seems like an electrical problem as it is not getting hot and the engine appears to be getting the appropriate mix of oxygen and fuel. Any help will be greatly appreciated.

 

[Sea Rider]

Welcome to Iboats,

Is the engine missing each 20 min as per clock metered ? At which throttle is doing so idle, medium, wot ? Your's is a 14 year oldie. Has the engine been well flushed after each outing ? Could be a CD, Ignition Coil related issue, heats up, shorts and engine drops dead ? Cools down and will re start back then and so on...

Happy Boating

 

[pvanv]

Could even be inadequate venting. You need to diagnose the problem while it is happening; IE, let it quit, and then check for fuel and spark.