runs fine but when cut off--won't crank

[rightsideup]

Boat-1996 Proline w/454 Mercruiser <br /><br />My problem is-boat runs good as long as motor is kept running but when cut off--like to fish or to rest won't crank does not sound unusual just does not crank. right before starting we turn the blowers on- open unit to motor-nothing but when it is towed (happened 2 times) and wenched onto the boat trailer it will start once on the trailer. both times I tried to start right before loading onto the trailer and it would not crank.<br /><br />Anybody have any ideas

 

[Wart T]

Re: runs fine but when cut off--won't crank

Any clicking sounds?<br /><br />All connections including grounds should be checked first. Not just at the battery. Check the ground on the engine by unbolting it and looking at it. Check all connections at the starter. <br /><br />There is a big ol wire going from the battery to the starter. There is also a smaller wire going to the starter. Next time it doesnt start, take the little handy dandy test light you thoughtfully brought with you and see if that smaller wire lights up when the key is turned to start. Make sure you don't get yourself tangled up in any moving parts if it does start.<br />If the light lights up and it doesnt start, move the test light to the big ol wire on the starter and try again. If the light stays lit all nice and bright you have a bad starter or solenoid. If the small wire does not light up the starter is not getting the "Hey it's time to wake up" call from the key switch. If the Big 'ol wire goes very dim then you have a bad battery or bad connection, or a short to ground inside the starter.<br />Make SURE the starter has continuity to ground. Testing is meaningless if the starter isnt grounding for some weird reason.<br /><br />You can have the starter repaired at any automotive rebuilder. They'll understand it is marine.

 

[hoot]

Re: runs fine but when cut off--won't crank

based on your description, check for fuel at the carb. when it doesn't crank, pull spark arrestor and hit throttle. does fuel spray into the carb? check fuel filters, igniton parts, basic things before going back out.