1999 Chaparral 1930ss 4.3 Mercruiser Starter Replacement

[boatstuff123]

Seeing if anyone has any advice for replacing the starter in the 4.3L Mercruiser EFI in a '99 Chaparral 1930. The engine cover does not provide much access at all. It appears I will have to remove the left seat to get to the rear bottom of the engine. Any advice is appreciated!

 

[alldodge]

Each boat is different and getting things out of the way to gain access is always the issue. Many are so tight that its easiest to remove the motor. The only good thing about a boat motor is if you have a lift it doesn't take that long

Are you sure it needs a starter?

 

[boatstuff123]

I am fairly certain. At the boat launch, i turned the ignition and no crank, then tried again and it fired right up. Then after an hour of riding around, I shut off the motor and when I tried to fire it back up, no crank at all. No solenoid click noise either, just fuel pump noise. Battery is fully charged. I was able to repeat similar symptoms on land. My guess is the 20 year old starter is on its way out.

 

[alldodge]

I have a 25 year old boat and its still going strong, did have a slave relay go out

No solenoid click noise either

Suggest doing a couple checks, and since there was no click at all, might be the slave relay

To engage the starter, the key switch sends 12V on the Yellow/Red wire, thru the neutral safety switch, then to the slave relay coil. The slave relay energizes and sends main battery power to the starter solenoid

 

[harringtondav]

Get a volt meter and trace things down before you go through the pain of a needless starter replacement.

Check voltage between the key switch in 'start' and the small start wire on the slave solenoid. Your key switch could be failing. No solenoid click indicates no signal voltage to the solenoid.

Edit: AD made his post before I finished mine. Trace for voltage back through his diagram. Other fail points include the neutral safety switch in the shift controller.

My 26 yr old starter is working fine.

 

[boatstuff123]

Thanks for the diagram, I'll work my way through the components with my multi-meter before replacing the starter. I eliminated the ignition switch and the neutral safety switch from the fault tree (prematurely probably) because it works when cold. Since its a no crank condition when hot, I figured it must be a heat soaked component like the starter.

 

[Lou C]

If you can access it try to put the pos probe of the voltmeter on the terminal for the yellow/red wire at the solenoid and the negative probe on a ground. Then have someone turn the key to start and see if you have 12v at the solenoid, this tells you if voltage is flowing thru the rest of the harness...
if the access is bad you may need to remove the exhaust manifold & elbow on that side.
I did mine recently and because my boat has the big bench seat with wood partitions that can be removed I was able to get at it but it still requires stretching. I installed a pmgr starter that weighs much less than the old direct drive unit. Make sure to use the right bolts if you install a new one.

 

[Lou C]

I'm guessing your OE starter was a PMGR unit but here's a comparison of old vs new....

 

[boatstuff123]

Thanks for the advice! while attempting to start it on land i heard occasional clicks from the slave solenoid this time, but no crank. I removed the slave solenoid and actuated it with a battery I had laying around and didn't read any connectivity across the 'output' posts. That was the problem! I got a new one for $13.50 on Amazon and boat started right up. Thanks Again!

 

[Lou C]

Great follow up! It goes to show that good diagnosis is the only way to really fix things right!

 

[cchamp]

I'm guessing your OE starter was a PMGR unit but here's a comparison of old vs new....

Bet that is a lot less likely to snap a starter bolt.

 

[Lou C]

The direct drive ones were supposed to have a front bracket mount (mine did), as long as you used the right bolts and the front mount they did not break bolts.

 

[boatstuff123]

The troubleshooting continues... No crank when hot. Occurred during 4 separate boat trips (very consistent) I started the engine perfectly fine when cold, went for a ride (1-2 hrs) and turned the boat off at the boat launch. All 4 times I would get no crank condition when turning the key (engine still hot). I could start the motor from jumping the relay I just replaced from the 'signal' side, so new relay (and everything downstream i.e. starter solenoid and starter) works fine. Multi-meter to the ignition key shows its functioning properly. I disassembled the Quicksilver 3000 classic throttle and confirmed the neutral safety switch works as well. The one thing that got the boat to crank from the key was unplugging the shift interrupter switch. It would crank/fire up immediately but then die after ~5 seconds. I do not see the shift interrupter switch as part of the ignition circuit so was confused why that worked, although it is a component in the engine compartment so figured it is more likely to be affected by engine heat. A real head-scratcher! Thanks for the help!

 

[alldodge]

The shift interrupter is part if the ignition but not part the the cranking (starting) circuit. If it cranks (turns over) but doesn't start, then maybe the interrupter, but if it does not crank then no. Maybe key switch or neutral safety

 

[nola mike]

The direct drive ones were supposed to have a front bracket mount (mine did), as long as you used the right bolts and the front mount they did not break bolts.

What are the right bolts?

 

[boatstuff123]

The shift interrupter is part if the ignition but not part the the cranking (starting) circuit. If it cranks (turns over) but doesn't start, then maybe the interrupter, but if it does not crank then no. Maybe key switch or neutral safety

I confirmed the key switch and neutral safety switch is functioning properly with a volt meter. After re-looking at the wiring diagram, the only component I did not test is the circuit breaker. Is there any chance the circuit breaker is heat sensitive (it is in the engine compartment), working fine when cold but not working when hot?

 

[alldodge]

The breaker just passes power, so when the key is turned to ON and the gauges come alive, and the motor can crank, the breaker is working, otherwise none of that would happen

 

[Lou C]

the right length, in that different starter housings may have slightly different size mount areas. If the bolts are too long they might not clamp down the starter tight enough and that can cause bolts to break. Measure the thickness of the mount area against the length of the bolts, the bolts when threaded into the block, should not be longer from the block surface to the edge of the bolt head that goes up against the starter, than the length of the mount area on the starter.
starter bolts also have a knurled section to keep them from loosening. You can see it in my pic above. So if you buy a new starter use the bolts it comes with or buy the installation kit (I had to do this with the ARCO).

 

[nola mike]

the right length, in that different starter housings may have slightly different size mount areas. If the bolts are too long they might not clamp down the starter tight enough and that can cause bolts to break. Measure the thickness of the mount area against the length of the bolts, the bolts when threaded into the block, should not be longer from the block surface to the edge of the bolt head that goes up against the starter, than the length of the mount area on the starter.
starter bolts also have a knurled section to keep them from loosening. You can see it in my pic above. So if you buy a new starter use the bolts it comes with or buy the installation kit (I had to do this with the ARCO).

Ah. My new starter came with bolts, but they were SAE. My old ones are metric. There's plenty of room in the block to thread the bolt, there's an extra couple of cm at least. Wondering what the knurl was for. I've been using permatex aviation on everything, maybe this gets some loc tite.

Also, not to get too off topic, but what's the point of that gasket? yours has it as well, but the old starter didn't.

 

[Lou C]

yeah no idea on the gasket. maybe if a freeze plug on the back of the engine leaks it keeps water from spraying on the rest of the starter? Who knows!