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Mercruiser Alpha One 5.7 Litre Distributor Cap Question

J

JoeBillquist

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I have a 2004 Bayliner with a Mercruiser Alpha One 5.7 Litre engine. I am replacing the distributor cap, rotor, and spark plug wires. When replacing the coil wire, the end of the replacement wire that connects to the ignotion coil doesn't have the same end feature as the existing one. The existing one has a brass clamp around the wire and it looks lke the wire is connected directly to the coil (I didn't want to remove it for fear of doing something that I couln't undo). This is what the new one looks like. I can add a picture of the current one if needed. Any thoughts??

Thanks
 
Are the plug wires Mercruiser OEM or aftermarket? https://www.marineengine.com/newparts/part_details.php?pnum=MER84-863656A05

Any reason you are changing the plug wires in particular?
The reason I sort of ask would be at least IMO, truthfully, unless those spark plug wires get damaged from other services done, excessive heat to where they start making the engine run bad because they start leaking spark from say years of physical contact of someone/something (IE: Rubbing on the engine, etc.), the OEM wires on boats tend to last a very, very long time to where they don't really seem to just ware down/out unless something else happened...Even weather doesn't really affect them...All mileage very of course but the need to change is low.

The coil wire can be challenging to get reinstalled correctly at times to make it not leak spark almost to point of your initial instinct of not wanting to touch it as it could cause other issues can hold true if not carefully re-done...The coil wire boot is sometimes the one of the most susceptible items to leak spark at the coil tower over to the - side of the wire post terminal.... Plus, the service manual suggests carefully using Mercury-Mercruiser insulating compound (notably OEM part 92-416691) as it is a specialized, grease-like silicone dielectric compound designed to seal, waterproof, and insulate electrical connections. It protects spark plug connections, electrical terminals, and ignition systems from moisture and corrosion, ensuring reliable engine operation... Good coil wire boot seatment is key as you're finding out.

https://forums.iboats.com/threads/coil-wire-install.781162/#post-6012514

 
need more info on engine........................Serial number, EFI, TBI, or carbed. Different configurations used different ignitions.

Link or specifics of what and where the new wires came from and brand.
 
kghost said:
need more info on engine........................Serial number, EFI, TBI, or carbed. Different configurations used different ignitions.

Link or specifics of what and where the new wires came from and brand.
Click to expand...
Thanks for your response. Sorry for the delay in replying. I was away from my laptop unexpectedly.
Engine serial number is 0L660961. I bought the wires a coupe of years ago so don't know the brand. I also now have a picture of the existing wire attached to the terminal with boot pulled back.
 
kghost said:
need more info on engine........................Serial number, EFI, TBI, or carbed. Different configurations used different ignitions.

Link or specifics of what and where the new wires came from and brand.
Click to expand...
Fun Times said:
Are the plug wires Mercruiser OEM or aftermarket? https://www.marineengine.com/newparts/part_details.php?pnum=MER84-863656A05

Any reason you are changing the plug wires in particular?
The reason I sort of ask would be at least IMO, truthfully, unless those spark plug wires get damaged from other services done, excessive heat to where they start making the engine run bad because they start leaking spark from say years of physical contact of someone/something (IE: Rubbing on the engine, etc.), the OEM wires on boats tend to last a very, very long time to where they don't really seem to just ware down/out unless something else happened...Even weather doesn't really affect them...All mileage very of course but the need to change is low.

The coil wire can be challenging to get reinstalled correctly at times to make it not leak spark almost to point of your initial instinct of not wanting to touch it as it could cause other issues can hold true if not carefully re-done...The coil wire boot is sometimes the one of the most susceptible items to leak spark at the coil tower over to the - side of the wire post terminal.... Plus, the service manual suggests carefully using Mercury-Mercruiser insulating compound (notably OEM part 92-416691) as it is a specialized, grease-like silicone dielectric compound designed to seal, waterproof, and insulate electrical connections. It protects spark plug connections, electrical terminals, and ignition systems from moisture and corrosion, ensuring reliable engine operation... Good coil wire boot seatment is key as you're finding out.

https://forums.iboats.com/threads/coil-wire-install.781162/#post-6012514

Click to expand...
Thanks for your response. Sorry for the delay in replying. I was away from my laptop unexpectedly.
Answers to your questions: 1) Plug wires are aftermarket. I bought the wires a couple of years ago so don't know the brand.
2) I am changing them at the recommendation of local marina. I had them change the spark plugs a couple of years ago and they recommended that I change the distributor, rotor, and wires since they were original and the boat is 20 years old. The engine did overheat about 8 years ago.
I also now have a picture of the existing wire attached to the terminal with boot pulled back.
 
Here is a link on this web site for your serial number.


Based on you have a Carburetor you also have a Thunderbolt V Ignition.

If the wire in the lousy picture is your coil wire, the Coil has a female pocket for a male 99% round brass/copper wire end and the inner core wire is bent back 180* and is crimped under the brass/copper crimped section so without a better picture it looks correct
 
what has been shown should work fine...make sure you clean up any crud where the boots seal and apply a bit of silicone dielectric grease to the boots...
 
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