Question about thunderbolt ignition

89larson

Recruit
Joined
Aug 31, 2017
Messages
1
HI all I'm new to the forum and looking for some quick help with my distributor and wires. I just recently changed my spark plugs and while doing so I noticed my plug wires are getting brittle. I haven't owned the boat long so not sure when they have been replaced. I went to the local marina to buy wires and they say they're a special order even though they have a Sierra marine kit on the wall that says good for all Gmail v8 blocks with electronic ignition. He also claims my distributor is a points ignition and not electronic. If I'm not mistaken I though thunderbolt ignitions were electronic or at least at this point in time?. The boat is an 89 with a 230 305 GM block.

Main question would be will these aftermarket wires work for me? I'm kind of losing faith in this parts guy based on what I read online and what I've researched about the thunderbolt ignition.
 
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Fun Times

Moderator
Staff member
Joined
May 16, 2009
Messages
9,293
Hi, welcome to iboats!

By chance do you happen to have your engine serial number handy?

Looks like the engine is an Inboard ? (MIE) Correct?? ... (AKA no Stern Drive) If so, did you let him know this because it seems the Stern Drive years were a bit older for the 230's vs some of the MIE's (not all though)...Maybe it confused him somewhere along the line.

Without the serial number and if my guess is correct, this should be your ignition parts, http://www.mercruiserparts.com/bam/s...y/31560/954/70

And here would be your engine parts,http://www.mercruiserparts.com/230-m...-8-1987-1995-1

Need to know if you have a right or left hand engine rotation too.
20
84-816761Q4
SPARK PLUG WIRE KIT (L.H. ROTATION)
813720A4
SS/ACT
magnify.gif

$71.57
$67.42
84-813720A4 / 84-816761K 4 Old #
New #, 84-816761Q4 = Sierra Numbers, 18-8821-1 &/or 18-8804-1
1
20
84-816761Q3
UG WIRE KIT (R.H. ROTATION)
813720A3
SS/ACT
magnify.gif

$72.16
$67.96
813720A3 Old #
New #, 84-816761Q 3 = Sierra numbers 18-8821-1 &/or 18-8804-1 - Ignition Wire Set
 
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achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Merc finished with points on the GM V8s around 1983. And it doesn't matter anyway, same leads for points or TB...

With plug wires, just take them all off (don't forget the coil to dissy lead!) and head into your local friendly auto parts shop. Drop them on the desk and ask for replacements in silicone. It will be about 1/4 the Merc price, and you'll end up with better leads.

Chris.....
 
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