4 cyl plug wires

PiratePast40

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AQ130D 4 cylinder. Sierra doesn't make plug wires for this motor anymore. The closest I can see is to use the wires for the newer overhead cam motors (125, 131, etc.). The asking price is $107 for a set. When I look at plug wire sets for 6 and 8 cylinder motors, the price is 1/3 to 1/2 the price. I intend to go with a coil with internal resistance and the electronic conversion kit. Since I'm getting rid of the ballast resistor, can I now use the less expensive plug wire sets or is there something more to the quality of wires required by a 4 cylinder engine?

Thanks for any insight.
 

Bt Doctur

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Re: 4 cyl plug wires

quality wires are quality wires,4-6-8 there all the same.Plus if you get the crimps and crimper you can cut them to size.
 

PiratePast40

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Re: 4 cyl plug wires

I would agree with you as to quality but these are the same brand - Sierra. I'm wondering if it has something to do with the solid plug boots on the 4 cylinder engines. Also wondering if that has something to do with the ballast resister. If it was just a question of quality, then why would the same brand be cheaper for 6 & 8 cylinder engines?

I'm wondering if I can buy a set of 6 or 8 cylinder marine grade plug wires and then just cut them down and crimp on new end fittings. The price difference just doesn't make sense to me unless these are all motors that are no longer manufactured.
 

kamby

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Re: 4 cyl plug wires

Ran into the same issue 100$ for wires for the 125a. I ended up getting the car version from autozone for $45 i think. They were better and thicker than what i had on mine. Same plug ends on the sparkplugs with metal encased around the rubber (if you take the metal off its teh same plug end. Plus they seem to seal around the plug better. They were the 7mm Solid core wire. Bosch Premium.

Just my .02
 

PiratePast40

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Re: 4 cyl plug wires

I don't remember where I read it but recall a discussion about material for marine spark plugs. From what I remember, they were essentially high quality cables with a different connector. I can see the difference on the spark plug end for my particular application but would like to find out why there is such a difference. With all the talk of certain death from using "non marine" electrical components, I just don't understand why an older 4 cylinder engine requires a different type of plug wire than a modern V8. I want to be safe but really wonder if it's not really an issue of safety but rather of parts supply for no longer manufactured engines. If anyone knows of a legitimate reason for using special wires for a 4 cylinder, I'd sure like to hear it.
 

Don S

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Re: 4 cyl plug wires

The OEM plug wires are solid core wires with resistors on the end of each wire. They all fire the same. If you can find other wires that do the same thing, go for it. There is no harm in using aftermarket or automotive plug wires in a boat. they do not spark externally and create a safety issue. All you need is plug wires that do the same thing as OEM wires. If they aren't equal, they will have lesser results.
 

kamby

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Re: 4 cyl plug wires

I cut the end of one of the old wires i had copper ends, white insulation, stranded coper wire. Languange on wire is swedish. Cut off one of the ends of the extra coil wire on new wires; Copper ends, white insulation, solid wire center. They are bosch Super Premium wires 7mm Optilayer. Plugs for the distributer were the same shape. The sparkplug end was the same but with the metal over the rubber boot.

These look like what i got, except my are grey
94df_1.JPG
 

PiratePast40

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Re: 4 cyl plug wires

Don,
Thaks for jumping in with the info on solid core and resistors on the ends. That may be the key to finding acceptable replacements. Since my plug wires have a separate, hard plastic fitting between the plug and the wire, I'm assuming that's the resistor so will keep that part and just replace the wires with 7mm solid core.

Kamby,
Thanks for the tutorial and describing what you found. It sure beats forking over 100 bucks each year for new cables as a part of the annual tuneup.
 

PiratePast40

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Re: 4 cyl plug wires

NAPA marine

As far as I know, NAPA sells Sierra electrical parts so that brings us back to the $107 a set. But thanks for the suggestion. Believe me, I'm searching everywhere I can - LOL
 

PiratePast40

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Re: 4 cyl plug wires

For the price difference, it looks like the Bosch set will be the way to go. Every brand I've seen that is specified for this engine has a special end at the spark plug. I'm assuming that has something with the resistor but really just guessing. I hate to deviate too far from what appears to be what was specced out originally. I'm not clear on resistance values and affect on voltage but really wondering if I need the resistor end if I'm getting rid of the ballast resistor by going with a coil with a resistor and the electronic pickup.
 

captmello

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Re: 4 cyl plug wires

Maybe you could try contacting the manufaturer of the new coil/ignition and see if they can help.
 

PiratePast40

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Re: 4 cyl plug wires

I did as you suggested and contacted Petronix concerning the wires. They said that to use the resistor ends if they come with the set. If you use a different set, use whatever comes with them.
 

captmello

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Re: 4 cyl plug wires

I did as you suggested and contacted Petronix concerning the wires. They said that to use the resistor ends if they come with the set. If you use a different set, use whatever comes with them.

Hummm...What does that mean? Sounds like they are saying you'll need oem spec resistor type wires anyway you go.

As always, let us know what you do.:)
 

kamby

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Re: 4 cyl plug wires

Hmm now im curious. I wonder if those bosch super premiums i got are resister type. My coil i belive is internal resistor, it has 1 12v wire and 1 neg wire and the wire going to the center distrib cap. I have the standard points system. They look new and clean so im not gonna bother replacing them with elecs. My boat runs great with the bosch wires and current points setup and new plugs.
 

captmello

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Re: 4 cyl plug wires

Keep in mind, the 125 is a newer generation of engine. I thought I read a post a few weeks back that were Don S said aq130 didn't have a ballast resistor. i'll check.

Ballast resistor would be before the coil. I'm not sure.:)
 
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PiratePast40

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Re: 4 cyl plug wires

My reaction to the answer from Petronics was about the same as you guys. It tells you what to use but not why. That's not necessarily a bad thing, just that most of us here like to understand why we're doing something one way or another. The Volvo 4 cylinders - auto or marine - have the hard plastic end piece on the plug end. I don't know if that's a resister or not or if it's a type of heat shield. In any case, I guess it doesn't matter and there are some times we probably don't need to think it to death - just do what the experts recommend.
 
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