Special case: 1500 coils in an 1100 with 1000 engine & Dyna S (with pics)

[Sidecar Bob]

I may be the only one with this setup but I thought it might help someone else so I took pics.

OK, Lets start with what I have and why I want to change it. Mr.H is an '83 GL1100 with a '79 GL1000 engine. I remember measuring the resistances of the 1000 and 1100 coils when I put it together in '95 and that they were the same but I don't remember what the measurements were.

I knew back then that when you pushed the 100's Start button the resistor was shorted via a diode so I assumed that the 1100 did the same thing. It started well so I never looked at that part of the schematic. A couple of years ago, while trying to figure out why I was having problems with the Dyna S ignition (turned out to be defective - replaced under warranty) I noticed that the 1100's wiring did not short the resistor and it has bothered me since.

I could add a diode and a couple of wires and make it work the same way as the 1000 but the coils (which seem to still work well) are 33 years old and I read here that you don't need the resistor if you use Dyna coils but the cheapest ones I could find would have cost me $170 Cdn. with shipping. I started this thread and Toehead & others suggested GL1500 coils so I ordered a set. The next post will detail my installation.

[Sidecar Bob]

Hello, my name is Bob and I'm a buffing addict. The original cast alloy coil brackets were dirty & dull and it has been my experience that when a part is buffed the smoother surface does not let as much dirt adhere (that's my story and I'm sticking to it) so I cleaned the brackets up and gave them a quick buff before bolting the coils on.

1500 coils 1100 brackets 1.jpg (53.86 KiB) Viewed 788 times

Toehead directed me to this thread, which has a lot of interesting info but, since it is about mounting the coils on a GL1000, didn't tell me what I needed until the last page where 82aspy posted a link to Dan's thread on classicgoldwings about mounting a set from a CBR on his 1100.

Dan used washers as spacers so that the terminals didn't touch the bracket

But I thought that, since I had to add a link to reach the mounting point on the frame anyway (see below) it would be simpler to invert the bracket

1500 coils 1100 brackets 2.jpg (44.9 KiB) Viewed 788 times

If I had used an M6 (or 1/4") nut & bolt to attach the link bracket to the coil bracket the nut would have been too close to one of the coil terminals for my comfort so I ran an M8 tap through the hole in the coil bracket and attached the link with an M8 screw. The only problem with this setup was that I couldn't tighten the screw with the coils mounted to the bike. After I wasted half an hour putting the assembly in & out of the frame trying to get the link at the correct angle so that its hole would line up with the mounting point on the frame I finally gave up and turned the hole into a slot. Much easier.

1500 coils 1100 brackets 3.jpg (52.96 KiB) Viewed 788 times

1500 coils 1100 brackets 4.jpg (52.34 KiB) Viewed 788 times

[Sidecar Bob]

Here is the assembly wired & ready to install. Note that rather than power the Dyna from the turn signal like the instructions say I connected it to the black/white wire where the ignition is supposed to get its power from.

1500 coils wired for Mr.jpg (96.97 KiB) Viewed 788 times

And here they are mounted.

1500 coils in 1100 frame.JPG (42.55 KiB) Viewed 788 times

Was it successful? Now I barely have to brush the Start button and the engine is running

[Track T 2411]

Very nice write-up, and photos. Other than the wiring for the Dyna, have you changed any other wiring, or are the 1500 coils plug and play on the 1100? I suppose that question is answered in one or both of the links you provided...

[Sidecar Bob]

It is my understanding that these coils can be used without modification (other than removing the resistor from the circuit) in either GL1000 or GL1100 but I would look through the threads I linked for more info.

[Toehead]

Looking good!

So, do you notice a decrease in start times?

[Sidecar Bob]

Definitely. With the 1100 coils + points and non-shorted ballast I had to crank it for maybe a second before it started. With the Dyna S it always needed 2-3 seconds. With the 1500 coils + Dyna S (no resistor) I barely have to touch the button and it is running.

[John Schmidt]

I did the same thing on my 1200 project, a while back I found the original coils had one acting intermittent. I also have a Valkyrie and had a spare set of coils for it, same as the 1500 Wings. The other neat thing was the plug wires still had the cylinder number bands on them so I used #1 thru #4, although I eventually installed aftermarket wires from Accel. I used the 1200 mount for them and adapted the 1500 coils to it, it's a solid mount but I also had to adjust for some space near one of the plug wires. As mentioned, just a split second bump of the start button and it's running.

[Sidecar Bob]

My special case just changed. In order to have better gearing for sidecar use I have replaced the 1000 engine with an 1100 but since I had known good '79 carbs (which don't have the vacuum port for the 1100 timing advance) and the bike was already set up for the Dyna S I converted the 1100 to run with the Dyna.

So now I have 1500 coils in an 1100 with an 1100 engine that has 1000 cams and Dyna S. And as far as I can tell it still works very nicely, thank you very much