main electrical power question
#1
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From: Cortlandt Manor NY
Im redoing alot in my boat and one of the things since I am doing a engine upgrade was I install an JS alternators marine 170amp alternator. MY question is this:
1. Batteries go into the 1,2,both, off switch
2. Out of the switch to the starter
3. 0/1 Ga wire from the single wire alt also goes to the starter
There is no fused protection there at all, I feel like between the stitch and the starter there should be a Heavy Duty breaker there or am I over thinking it?

Getting close to fire up. Wiring and a bunch of little items to check off the list which takes the most time.
Another question I am running a carb since the Holley EFI is on back order, it used to be an MPI mag injection system but with the carb 1/2 throttle on the stick is wide open on the carb. I assume there is no adjustment to change the ratio of the stick to the carb opening?
1. Batteries go into the 1,2,both, off switch
2. Out of the switch to the starter
3. 0/1 Ga wire from the single wire alt also goes to the starter
There is no fused protection there at all, I feel like between the stitch and the starter there should be a Heavy Duty breaker there or am I over thinking it?

Getting close to fire up. Wiring and a bunch of little items to check off the list which takes the most time.
Another question I am running a carb since the Holley EFI is on back order, it used to be an MPI mag injection system but with the carb 1/2 throttle on the stick is wide open on the carb. I assume there is no adjustment to change the ratio of the stick to the carb opening?
Last edited by Joeyboost; 07-10-2023 at 10:06 AM.
#4
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In regards to circuit protection, I've never seen anything between the batt, batt switch and starter. Any device in that path would likely restrict current when starter is engaged.
Between the alt output and the starter, I have seen high current breakers (usually down by the starter) That's probably a good idea. If you've ever got a wrench up against the output terminal on the rear of alt and ground, it gets exciting real quick. Also if something goes south electrically inside the alt, a breaker would stop the carnage before it got completely out of hand.
Between the alt output and the starter, I have seen high current breakers (usually down by the starter) That's probably a good idea. If you've ever got a wrench up against the output terminal on the rear of alt and ground, it gets exciting real quick. Also if something goes south electrically inside the alt, a breaker would stop the carnage before it got completely out of hand.
#5
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From: Cortlandt Manor NY
In regards to circuit protection, I've never seen anything between the batt, batt switch and starter. Any device in that path would likely restrict current when starter is engaged.
Between the alt output and the starter, I have seen high current breakers (usually down by the starter) That's probably a good idea. If you've ever got a wrench up against the output terminal on the rear of alt and ground, it gets exciting real quick. Also if something goes south electrically inside the alt, a breaker would stop the carnage before it got completely out of hand.
Between the alt output and the starter, I have seen high current breakers (usually down by the starter) That's probably a good idea. If you've ever got a wrench up against the output terminal on the rear of alt and ground, it gets exciting real quick. Also if something goes south electrically inside the alt, a breaker would stop the carnage before it got completely out of hand.
#6
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From: Cortlandt Manor NY
On the carb the throttle linkage attachment point only has one hole that fits the cable bolt properly its closer to the swivel point than the other attachment points but half way on the control opens all 4 butterfly's 100% Ill have to pull the controls and see if they have additional cable attachment points.
#7
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Being that you have pretty decent access to the starter, if the breaker ever trips ( due to overloading it), you should be able to bypass it to get yourself back into port. Depending on the configuration of the wiring connectors, might be a good idea to have a custom jumper available in your tool bag if needed.
Prev owner of my boat lost a trim pump fuse a few miles out in the gulf. Once he got back in, he installed short wires and a insulated spade connector to bypass the fuse if needed. Same principle.
Last edited by zz28zz; 07-11-2023 at 08:16 PM.
#8
On the carb the throttle linkage attachment point only has one hole that fits the cable bolt properly its closer to the swivel point than the other attachment points but half way on the control opens all 4 butterfly's 100% Ill have to pull the controls and see if they have additional cable attachment points.
Google "holley carb throttle linkage bushing"
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#9
The starter circuit itself is normally not fused or current limited.
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#10
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From: Cortlandt Manor NY
That is actually a fuse. Nothing wrong with keeping that however I would also keep a spare on board. Just make sure to attach the battery directly to the starter post and the wire to the alternator to the fuse.
The starter circuit itself is normally not fused or current limited.
The starter circuit itself is normally not fused or current limited.
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