Ignition Problem

[bianchija]

Hi Everyone,

I'm helping my brother work on his 1993 Sea Ray overnighter. The boat has a 4.3 liter Mercruiser package, and the starter went out.

I helped him change the starter and we're now having some issues. First and foremost the ignition fuse blows rather frequently when cranking. It's never done this before. You can crank the engine about 5 times before the fuse will blow.

Second, before the fuse blows and while it's cranking it appears to make a knocking noise with each full crank of the engine. This has never been heard before either.

I can't think of how these two issues could be related, but who knows. My thought is to start by validating the wiring to fix the fues issue, and then see if that would correct the knocking as well? My concern is that we did our best to re-wire everything the same as it was before, so I'm not sure what could be wrong.

Has anyone ever heard of anything like this, or do you have any ideas as to what could have gone wrong?

Thanks a bunch,

Joe

 

[calwldlif]

Re: Ignition Problem

I HOPE IT IS A MARINE STARTER?
Sounds like the new starter is binding?
Did you get a rebuilt one?
rebuilt yours?
It is a good idea to get any starter checked
before installing. The auto parts stores often
have equip to measure amp draw on a starter.
There are specs for the normal range of amp
draw on aparticular starter.
Remove starter and get it checked, look for
signs of dragging, rubbing, scoring.
Thats my WAG

 

[bianchija]

Re: Ignition Problem

Yeah, it's a starter from a local marine store.

I'll pull it back out and check for the rubbing, scoring, etc. Thanks for the help!

 

[bruceb58]

Re: Ignition Problem

Do you have the wire that eventually goes to the coil on the correct terminal of the start solenoid?

 

[Chris1956]

Re: Ignition Problem

Joe, That knock sounds like premature firing of the cylinder, or you have bent a valve. You might like to remove the spark plugs and turn the motor over with a socket and breaker bar to see if something is hitting.

That still shouldn't blow the ignition fuse. When you say fuse you mean the circuit breaker mounted on the front of the motor? on mine that is a 50A breaker for the starter solenoid. If that is popping, the starter (master) solenoir and/or the slave solenoid is bad. If you have access to a heavy duty (~500A) ammeter, you could test the current of the starter, as well.