Hello Y'all!!
Since This is my First post, Here Goes... I have Twin 350's and the starboard engine sputtered and shut down cruising at 2900 rpms. prior to this, (it did not registerwith me.) when moving it off the trailerand loading it into the water, the rpms seemed sluggish in neutral, compared to the port engine. I am going Back up this weekend and so far i am armed with the following knowledge:
1.) check the return line to the fuel pump, make sure it has no fuel going back to it. i learned supposenly that this indicates a bad pump.
2.) swap trhe igintion coil if number one proves nothing...

currently the engine has 260 hours on it and when trying to start the motor, it cranks, but doesn't catch. (even if the throttle is on full. Is there anything else i should check?
I appreciate your response.....
Happy labor day weekend Folks!!

Check your kill switch
Check for spark
Make sure the distributor is not loose
I am sure that I can think of some more.

Jon

Check for spark first, most likely culpret. If no spark, could be the distributor module located in the bottom, backside of the distributor under the rotor. Happened to mine, same symptoms. Costs about 60 bucks for new Merc unit. New units have been revised. They are now sealed. Old ones had exposed terminations that corrode due to condensation in the bottom of the distributor. Easy fix.