Steve Saunders Goldwing Forums - View Single Post - Convert 4cyl. Oldwing coils to newer GL1500 Coils for Hotter spark

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post #1 of (permalink) Old 04-14-2014, 09:02 AM Thread Starter
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westgl's Avatar
Join Date: Apr 2008
Location: Central Point, Oregon, USA
Posts: 1,331
Convert 4cyl. Oldwing coils to newer GL1500 Coils for Hotter spark

Went to start my 86' GL1200I Naked, No Start.

Pulled plugs checked for spark at all 4 plugs Nothing.

Checked my coils voltage 12V in, nothing out, on one coil.

Checked other coil, 12v in, 12v Out on the other coil.

Checked main fuse, I had converted main 30 amp dogbone fuse to a ATO blade fuse about 3 years ago.

It was burnt, Hum, replaced it, still, same at coils.

I had bought for $25.00 shipping included (EBAY), a set of 3ea coils including the spark plug wires from a 98' GL1500 6cyl.

The coils that I used were MP08, GL1500 coil and Spark Plug wires.

Hardest part was finding where I put them in my shop, but once located, I proceeded.

I thought I would swap in the MP08 coils from the GL1500 and test to see if the engine would start.

I new these MP08 GL1500 coils worked with the 4cyl. engines, cause I had put them on my 83' GL1100 a year earlier.

So I just un-wired the old coils, (while they were still in place) and then wired the new (Old) MP08 coils while hanging over the frame for test purposes only.

When hanging over the frame only 3 Spark Plug wires would reach the spark Plugs, that was good enough to verify spark, with all plugs in.

I started it, on 3 cylinders and it started much faster, and ran smooth.

It started faster than it had ever started before.

So that proved that I had a Internally shorted coil. Especially after further testing.

So removed the old coils, and Old Spark Plug wires.

Then I removed the Old Coil Mounts, I used My 86' coil mounts, with the new MP08 Coils, that way everything would mount correctly with No modifications to mounting.

When disassembling the MP08 GL1500 Coils,

I made sure to select the MP08 coils with the Spark Plug wires numbered 1,2,3,4, that way they are numbered for the corresponding cylinders on the 4cyl. Oldwing.

All I had to do is add one extra flat washer Under the mount where the wiring plugs into the coils, to provide more clearance for the wiring in this area.

Meaning, it already had One washer under this mount, I added One more for two washers under each mounting screw, on the wiring side only, to provide a little more spacing.

So two extra washers total.

Put it all back together, started it up this time on all 4 Cylinders, it started up faster than it had in the past, and was Very Smooth, even when cold.

To me the MP08 GL1500 Coil and Spark Plug Wires are a Upgrade.

and all for $25 to my door a inexpensive one.

There are Many More GL1500's out there than 4Cyl. goldwings,

Take advantage of the Volume of parts.

A couple of things I will mention, though that are different.

1. MP08 GL1500 Coils are a little Smaller than the 4cyl coils, but after mounted using the 4cyl. mounts they mount the same.

2. The GL1500 Spark Plug Wire are Different from the 4cyl. Plug wires.
the screw caps to the coils for the plug wires are smaller, you may be able to mix and match here but I wanted better and matching wires to the coils.

I test rode bike for over 200 miles, and it runs Much Smoother than it ever had before.

One other thing.

When you buy the MP08 GL1500 Coils, I got Three Coils, and Six plug wires they were mounted to the GL1500 coils Mounts (i did NOT use the GL1500 coils Mounts) I only used 2 of the coils and 4 of the Plug Wires.

This gave me One spare coil and Two spare Plug Wires for the shelf.

All for $25.00 to my door.

Current Bikes,
1983 GL1100 72K 32DFT Single 2-bbl Progressive Carb, and Runs Excellent,
1984 GL1200A 55K Reverse Trike Project, Single 2bbl. Progressive carb
1986 GL1200 Interstate, Now Naked, She just turned 43K
1988 GL1500/6 Phantom Grey 2-bbl SCC Trike Mustang GT Rearend, Rear Disc Brakes, HD Mufflers
2005 Burgman 650 20K
07' M109R 1855 miles 130hp 120ft lb torque Reverse Trike 99' Miata front suspension
2013 Honda NC700X 4k, AVG 77.68mpg
2015 Valkyrie, 4K miles Hot rod, Excellent bike
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