Changing Spark Plug Wires

[blk93jeepzj]

Like the title implies, looking to change out my plug wires. I have a 2004 Wakesetter with the Monsoon 340.

My question is do I need the Indmar plug wires for the marine rating? Or can I go to the local auto parts store and get a set for a late 90's early 2000's 5.7? Also while I am at it, which NGK plugs should I be using. I did take a look thru the archives and could not find anything conclusive.

Thanks,

Robert

[zone 5]

There is no such thing as a marine rated plug wire. Stock wires on older Malibu's were Taylor, which are great wires.

IN 1998 they called for AC MR43T or AC MR43LTS (depending on the specific motor) plugs on the Monsoon EFI. I don't know what Indmar may have changed since then so it could be different., If you want NGK, the auto parts store should be able to cross them.

Edited April 3, 2014 by zone 5

[blk93jeepzj]

Thanks for the fast response. I didn't think that plug wires were marine rated but thought I would ask the crew first.

[malibuparadise]

When I put in my Mallory "marine" Distributor (w/ Magnetic Pickup--YLM624BV), the wires for it were termed as marine too, and if the hype below for these components is true, good for me ;-) Pricey yes....

"Replace your OE distributor with one of these modern, high performance marine magnetic breakerless distributors from Mallory. Their complete, self-contained ignition system combines the triggering device and amplifier into a single unit that sits inside the distributor housing. The self-contained module/pickup assembly has no moving parts to wear out, making them superior to many other designs. Their time-tested breakerless ignition circuit and surface-mounted, Thermal-Clad construction provide reliability in harsh marine environments. Designed for 12 V negative-ground systems, they improve combustion efficiency and spark plug life, provide accurate timing, and have a simple wiring hookup for easy installation. They're designed to work with both OE and aftermarket coils, so you're sure to find the combination you need."

"Mallory Marine Promaster Spark Plug Wires are made with only the best components. They have a tightly wound fiberglass braid that forms a permanent bond between the EPDM inner layer and the outer silicone jacket to increase wire strength and eliminate terminal pull-off.

Features

• Ultra low resistance spiral core delivers high-energy output for maximum spark at the plug
  • Excellent RFI/EMI suppression for even the most sensitive high-tech onboard electronics
    • 8mm ozone-resistant blue silicone jackets repel water, oil, grease & fuel and withstand up to 500°
      • Custom fit for your specific marine application and ready to install"

Edited April 3, 2014 by malibuparadise

[Woodski]

Plug wires are not abused in a typical boat application as the exhaust manifolds are water cooled so they don't get as hot as in automotive applications.

Due to the electronics, speed control and stereo systems, make sure you get good RF suppression wires, they will need to be the spiral wound versions.

[zone 5]

When I put in my Mallory "marine" Distributor (w/ Magnetic Pickup--YLM624BV), the wires for it were termed as marine too, and if the hype below for these components is true, good for me ;-) Pricey yes....

"Replace your OE distributor with one of these modern, high performance marine magnetic breakerless distributors from Mallory. Their complete, self-contained ignition system combines the triggering device and amplifier into a single unit that sits inside the distributor housing. The self-contained module/pickup assembly has no moving parts to wear out, making them superior to many other designs. Their time-tested breakerless ignition circuit and surface-mounted, Thermal-Clad construction provide reliability in harsh marine environments. Designed for 12 V negative-ground systems, they improve combustion efficiency and spark plug life, provide accurate timing, and have a simple wiring hookup for easy installation. They're designed to work with both OE and aftermarket coils, so you're sure to find the combination you need."

"Mallory Marine Promaster Spark Plug Wires are made with only the best components. They have a tightly wound fiberglass braid that forms a permanent bond between the EPDM inner layer and the outer silicone jacket to increase wire strength and eliminate terminal pull-off.

Features

• Ultra low resistance spiral core delivers high-energy output for maximum spark at the plug
  • Excellent RFI/EMI suppression for even the most sensitive high-tech onboard electronics
    • 8mm ozone-resistant blue silicone jackets repel water, oil, grease & fuel and withstand up to 500°
      • Custom fit for your specific marine application and ready to install"

I like Mallory's wording on their wires.. The distributor is absolutly different in a boat as compared to a car.So your expense was not wasted by any means.

[Nitrousbird]

The Indmar wires on my motor were complete garbage - and they wanted $190 to replace that junk.

There is nothing off-the-shelf since Indmar did a remote coil pack mount. I just bought a cut-to-fit set of wires from Jegs + the proper wire crimper. Didn't take that long to put together and I got much nicer wires for 1/4 the price. Since the Monsoon uses a distributor I'm sure many different off-the-shelf wires for a GEN-I SBC will work just fine.

[rushman]

I know I may get some grief for asking this question BUT is it REALLY that necessary to change the plug wires? My boat has maybe 350 hrs on it but it is going into its 11th summer. I change cap and rotor about every 3 yrs and replaced plugs 2 yrs ago. I am lucky to put on 35 hrs/year which I know is sad. I haven't changed the wires ever. Do they really break down? Yours thoughts?

[Nitrousbird]

I know I may get some grief for asking this question BUT is it REALLY that necessary to change the plug wires? My boat has maybe 350 hrs on it but it is going into its 11th summer. I change cap and rotor about every 3 yrs and replaced plugs 2 yrs ago. I am lucky to put on 35 hrs/year which I know is sad. I haven't changed the wires ever. Do they really break down? Yours thoughts?

I didn't change mine for my health. I changed mine because of a misfire...the a couple of the Indmar wires fell apart when I removed them. Did it in 2011, 340ish hours at the time.

[RTS]

When I changed my plug wires after about 8 years, I put an ohmmeter to the old ones and the news ones. That data is available on this site somewhere, I posted the results. I think it was early last year if you want to look it up.

I was shocked by what I found. The resistance of some of the old wires were at least 5 times that of the new wires. So I would say Yes, they break down. Either that or Indmar uses crap wires...

I ordered a set from either skidim or Bakes...can't remember which one. They were about $50, I think. It may have been in my head, but I think it cleaned up the idle a little bit.

Edit: here's the data from that old thread...measured in KOhms

Wire, Old, New

Coil, 14.15, 3.39
1, 30.0, 7.5
2, 21.2, 7.45
3, 19.3, 7.5
4, 17.3, 5.9
5, 17.7, 5.9
6, 14.1, 5.1
7, 12.5, 5.8
8, 21.2, 4.4

Edited April 4, 2014 by RTS

[Woodski]

@rushman: in a marine application, heat won't be the main driver for your plug wires to need replacement, vibration and time will be. The inner spiral wound core will break down over time (as noted by changing resistance) and as the outer insulation ages it will become more brittle and then the spark leaks (look under the cover in the dark and you can sometimes see the arcing). There is a decent probability that after 11 years, you might need a new set of wires, not due to the 350 hours. As Zone 5 noted, no need to buy from your marine supplier, local auto parts stores will provide what you need in a non assembled version since distributor and routing tend to or can be specific. Make sure you get resistor wires (spiral wound) if you use your stereo or have speed control.

The interesting reality is there are really only a few wire suppliers, the various different brands simply assemble and package the wires as their brand.

Edited April 4, 2014 by Woodski

[Steve B.]

When I changed my plug wires after about 8 years, I put an ohmmeter to the old ones and the news ones. That data is available on this site somewhere, I posted the results. I think it was early last year if you want to look it up.

I was shocked by what I found. The resistance of some of the old wires were at least 5 times that of the new wires. So I would say Yes, they break down. Either that or Indmar uses crap wires...

I ordered a set from either skidim or Bakes...can't remember which one. They were about $50, I think. It may have been in my head, but I think it cleaned up the idle a little bit.

Edit: here's the data from that old thread...measured in KOhms

Wire, Old, New

Coil, 14.15, 3.39

1, 30.0, 7.5

2, 21.2, 7.45

3, 19.3, 7.5

4, 17.3, 5.9

5, 17.7, 5.9

6, 14.1, 5.1

7, 12.5, 5.8

8, 21.2, 4.4

That is interesting, I guess the question is, what effect does it really have, especially if 50,000 volts is driving it?

Steve B.

[zone 5]

That is interesting, I guess the question is, what effect does it really have, especially if 50,000 volts is driving it?

Steve B.

You have to remember that its a lot of volts, but not many amps,(less than 1) The two together is where the power comes from. So those numbers are significant in the percentage reduction he had in his resistance. Also, when a plug wire gets a higher resistance, it causes the energy from the coil to "back up" while fighting to get through the wire, which over time can cause the coil to fail

[zone 5]

If you have a distributor ignition, Taylor makes wires that they call "under headers" that should fit correctly. They work perfectly on BB marine, so I would think they would do the same on SB.

http://www.taylorvertex.com/Products/pdfs/quickReference.pdf

[Steve B.]

You have to remember that its a lot of volts, but not many amps,(less than 1) The two together is where the power comes from. So those numbers are significant in the percentage reduction he had in his resistance. Also, when a plug wire gets a higher resistance, it causes the energy from the coil to "back up" while fighting to get through the wire, which over time can cause the coil to fail

VSWR !

Steve B.

[rushman]

I was going to order some wires from Discount Inboard Marine for my 2004 Monsoon 340. The following were two different sets. Are these okay wires or should I be looking elsewhere. Mine are 11 yrs old and time to change I am sure. I do not know why this is typing with a line through it?????? If those links don't work because of this line....the p/n from SKIDIM is 22806 or 1220. Thanks for your help.

http://www.skidim.com/prodinfo.asp?number=75-6002

http://www.skidim.com/prodinfo.asp?number=RK120011

[nevertwobig]

I've got the 320 monsoon and ordered the red set. They are a good set!

Sent from my iPhone using Tapatalk

[GlassMaster]

I have the 340 monsoon. I didn't have a record of how many hours were on the ignition parts because I purchased the boat used. I will say, the boat seemed to be running fine. But I put 25 more hours on it since purchasing it and the engine clock just hit 500. So being Spring Tune-Up time, all wires, cap and rotor, and plugs are getting replaced.

Wires - I just received the red wire set from Bakes. The new wires are made by Taylor and came in a zip lock marked 75002. They are exactly the same length as the blue Indmars, but the plug side boot is slightly taller (still fit well) and the cables were not numbered like my old blue set. After laying them all out so I could number them, I discovered the lengths were all in sequential order from longest to shortest 1-2-3-4-5-6-7-8-coil. Knowing wire #1 is the longest, then #2 etc, and the coil is shortest made it easy to keep them all organized.

I then took Ohm measurements to compare the old Indmar wire set to the new Taylor set using a Fluke multi-meter. I held the contacts for several seconds until the values settled to the hundredth to get these values.

Wire, Old, New

1, 14.44, 6.54

2, 13.20, 6.55

3, 13.18, 6.65

4, 13.84, 6.57

5, 11.92, 6.65

6, 11.08, 5.78

7, 8.86, 4.09

8, 8.72, 4.89

C, 6.04, 2.77

Rotor Kit - I discovered the coil had attracted a lot of carbon dust, mount was loose enough to easily wiggle on the mount so I had to tighten it up and cleaned it off. The cap had aluminum pins on top with brass pins internally, which were all scorched. The rotor was extra filthy with several carbon tracks that had to be impacting performance. I replaced it with an all brass rotor kit from MSD #5502. It was a perfect fit, I then put some dielectric tune-up grease on the tips before connecting the wires.

Plugs - I also decided to change out the the original AC 41-932 iridium plugs because even though they were still correctly gapped to 0.060, the ceramic bodies looked terrible and all of the tips were very sooty. I replaced them with the NGK TR5 #2238, plus one for the spare. I trust the overwhelming board discussions over the years that these copper core plugs perform better in non-CAT monsoon engines, and they cost much less, and I replace plugs every year anyway. I put dielectric tune-up grease on the tips and anti-sieze on the threads.

[esebrown]

On 5/15/2014 at 1:30 PM, GlassMaster said:

I have the 340 monsoon. I didn't have a record of how many hours were on the ignition parts because I purchased the boat used. I will say, the boat seemed to be running fine. But I put 25 more hours on it since purchasing it and the engine clock just hit 500. So being Spring Tune-Up time, all wires, cap and rotor, and plugs are getting replaced.

Wires - I just received the red wire set from Bakes. The new wires are made by Taylor and came in a zip lock marked 75002. They are exactly the same length as the blue Indmars, but the plug side boot is slightly taller (still fit well) and the cables were not numbered like my old blue set. After laying them all out so I could number them, I discovered the lengths were all in sequential order from longest to shortest 1-2-3-4-5-6-7-8-coil. Knowing wire #1 is the longest, then #2 etc, and the coil is shortest made it easy to keep them all organized.

I then took Ohm measurements to compare the old Indmar wire set to the new Taylor set using a Fluke multi-meter. I held the contacts for several seconds until the values settled to the hundredth to get these values.

Wire, Old, New

1, 14.44, 6.54

2, 13.20, 6.55

3, 13.18, 6.65

4, 13.84, 6.57

5, 11.92, 6.65

6, 11.08, 5.78

7, 8.86, 4.09

8, 8.72, 4.89

C, 6.04, 2.77

Rotor Kit - I discovered the coil had attracted a lot of carbon dust, mount was loose enough to easily wiggle on the mount so I had to tighten it up and cleaned it off. The cap had aluminum pins on top with brass pins internally, which were all scorched. The rotor was extra filthy with several carbon tracks that had to be impacting performance. I replaced it with an all brass rotor kit from MSD #5502. It was a perfect fit, I then put some dielectric tune-up grease on the tips before connecting the wires.

 

Plugs - I also decided to change out the the original AC 41-932 iridium plugs because even though they were still correctly gapped to 0.060, the ceramic bodies looked terrible and all of the tips were very sooty. I replaced them with the NGK TR5 #2238, plus one for the spare. I trust the overwhelming board discussions over the years that these copper core plugs perform better in non-CAT monsoon engines, and they cost much less, and I replace plugs every year anyway. I put dielectric tune-up grease on the tips and anti-sieze on the threads.

I have a 2005 23 LSV with the Monsoon 340. Do you know the proper distributor model no.? Mine is pretty corroded inside and while I am putting a new cap and rotor, I thought it makes sense to replace it all. Very difficult to find which one fits it though. Any help is appreciated.

[oldjeep]

33 minutes ago, esebrown said:

I have a 2005 23 LSV with the Monsoon 340. Do you know the proper distributor model no.? Mine is pretty corroded inside and while I am putting a new cap and rotor, I thought it makes sense to replace it all. Very difficult to find which one fits it though. Any help is appreciated.

Have a picture of the cap?  That typically helps

[Eagleboy99]

2 hours ago, esebrown said:

I have a 2005 23 LSV with the Monsoon 340. Do you know the proper distributor model no.? Mine is pretty corroded inside and while I am putting a new cap and rotor, I thought it makes sense to replace it all. Very difficult to find which one fits it though. Any help is appreciated.

https://www.bakesonline.com/distributor-complete-delco-marine-distributor.html ?

[oldjeep]

4 minutes ago, Eagleboy99 said:

https://www.bakesonline.com/distributor-complete-delco-marine-distributor.html ?

If that is the one then it is called a Delco EST cap

[GlassMaster]

Wow I can't believe it's been 5 years since tuning up my Monsoon ignition. But as an update to this old thread, everything is still working flawlessly.

[formulaben]

On 5/6/2019 at 10:57 AM, GlassMaster said:

Wow I can't believe it's been 5 years since tuning up my Monsoon ignition. But as an update to this old thread, everything is still working flawlessly.

I'd be curious to see what 5 years and whatever hours you've logged has done to the resistances readings you logged 5 years go.