Mercruiser 4.3 will not turn over

97rinker

Recruit
Joined
Oct 8, 2015
Messages
3
Hello,
I have a 1997 Rinker with a Mercruiser 4.3 the other day I started the boat on the muffs to prepare to winterize, it was running for about 10 - 15 min (I was waiting for the thermostat to open) when the engine died, acted like it ran out of gas. I tried restarting and it would start and then stall. After each time it would stall I could hear the fuel pump running. After about 4 or 5 times or trying to restart I went to turn the key and the 20A fuse near the battery blew. I verified that all connections were tight, I even changed to another good battery and when I turn the key to start I heard the starter click like it does to engage, but the fuse blew. So I proceeded to disconnect the alternator and fuel pump and oil pressure sender, and elec choke, one at a time to rule out individual components. Each time I would try to start the fuse would blow. So then I tried jumping the starter at the both solenoids primary (at the starter) and secondary (near the circuit breaker) I get spark, but starter doesnt do anything. I then removed the starter and went to auto parts store, it tested good, but made a loud growling sound. (tested it like 5 times). I also rotated the motor over at the flywheel without starter in place, it turned over fine! I then reinstalled starter in boat, hit the key it the motor turned over no problem. When I shut the key off and tried to crank it over again, nothing happened. Fuse DID NOT blow this time, but all dash lights dim and everything loses power. I'm thinking even though the starter tested good, that under a load it is NO GOOD???? but honestly at this point I'm not sure where to look.

I also cant find any broken or chaffed wires
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,582
Check you slave solenoid, if its drawing to much current it can blow the fuse when cranking
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,582
Here is the slave solenoid/relay part number 89-96054T
Slave Relay 89-96054T.jpg
The bottom two terminals are used to energize, the top two terminals supply power to the starter.

The wiring diagram below shows the 20amp fuse (b) and relay (c). One side of the key start circuit goes to ground the other comes from the key. Unable to give you exact ohm values for the relay but it should be 100 or so ohms. The item cost under $15 and if it has never been replaced you might just replace it.

Start Circuit Merc.jpg
 

97rinker

Recruit
Joined
Oct 8, 2015
Messages
3
Update: found out the electrical issue was a bad battery cable, but now the motor starts and will only run if i hold the choke closed. It will run on idle no problem as long as I hold the choke closed. I'm assuming the carb is dirty or something, but what is not making sense to me is the fact that the boat ran great all summer, It was sitting maybe 2 - 3 weeks, covered up, and ran for 10 - 15 min the other day while I was trying to winterize it, then stalled.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,582
Let me make sure I got this right. It kept blowing the 20 amp fuse, several times, and now your saying that it was a bad battery cable. No, don't believe it, a bad battery cable will not blow a fuse.

As for your current engine issue, start with the filters, check contents and if they have not been changed, do that. Next check fuel pressure by putting a tee between the fuel pump and carb. Pressure should be between 4 to 7 psi. If that checks out, check fuel lines, anti-siphon valve and then rebuild carb
 
Top