Coil relay mod - what a difference!

[Skinner]

Today I did the coil relay mod on my 1981 GS650GL. The bike was running very well - when warm it idles nicely, returns to idle without hanging, good power, etc. There were no indications of it running rich with the exception of the black, sooty plugs. Even when I would adjust the mixture to intentionally run lean the plugs would still get sooty. The float levels are spot on so, after some searching, the coil relay mod seemed like it might be a solution.

The bike always started immediately on choke, but never ran smoothly. It kind of sputtered and would eventually take off as the bike warmed up. It was a good 2 minutes before the bike would idle nicely with the choke off. Well, today I loosely put together the coil mod wiring just to make sure my connections were correct. I started it on choke and the difference was immediately noticeable. It was smooth and the RPMs climbed almost immediately. Wow, I was quite pleased. So I went to work soldering my connections, cleaning up the wiring and making it all look pretty. I put everything back together and started it up again. This was about 2 hours after the first time so the engine was cold. It fired up right away but settled into a smooth idle at around 800 rpm. I thought that was odd, but it wasn't running roughly, sputtering or anything like that. I then realized that I didn't pull the choke knob out. The bike would never start and stay running when cold before this mod. I'm quite pleased. Now for a road test to see if there is any noticeable difference when riding.

Cheers!
K

[ShadowFocus603]

Your experiences mimic my own on my 850. Great mod to make time for.

[Grimly]

It will pull smoother and run nicer when the LT connections are all clean, with the coils getting what they should.
The coil relay mod is something I've been meaning to do for a while.

[Redman]

What was the voltage at the coils before...?

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[Skinner]

What was the voltage at the coils before...?

.

I was getting 9.8 volts at the coils before the mod, around 11.9 now. Well worth the work.

After a short ride last night I'm happy with the results. It now purrs like a kitten at idle and pulls smoother. It even sounds different both at idle and when accelerating.

Cheers!
K

[Kpaige]

Do you have a link to this mod?

[posplayr]

Do you have a link to this mod?

Your are in luck there is quite a selection. Do a search for your favorite flavor.

[Kpaige]

I really have not had much luck searching here it is a challenge.

[posplayr]

I really have not had much luck searching here it is a challenge.

google works; I would try basscliff coil relay mod

[raygun]

Come on y'all http://members.dslextreme.com/users/...relay_mod.html

[limeex2]

Come on y'all http://members.dslextreme.com/users/...relay_mod.html

Thank you for not being an a$$

[mainiac]

I did mine a couple of weeks ago. I was getting 10.1 at the coils and now 11.9. I cant even begin to describe the difference. Last year the best i could get was around 35 mpg. I am looking forward to seeing what I get now, if it ever warms up enough to burn a tank of gas.

[BillH]

I did mine a couple of weeks ago. I was getting 10.1 at the coils and now 11.9. I cant even begin to describe the difference. Last year the best i could get was around 35 mpg. I am looking forward to seeing what I get now, if it ever warms up enough to burn a tank of gas.

I got a question regarding the relay ignition coil mod. So in my case I was measuring 9.2 volts at my coils. Way low. I am currently in process of installing the relay mod and I understand the original orange/white wire in the big bundle (which is where I had the 9.2 volts) will be powering the coil of the relay and the new clean 12v will be on a wiper of the relay. My question is - how low a voltage on the coil of the relay before you would see chattering on the relay ? I see you had 10.1 volts and apparently there is no chattering.

I excited to see the difference after the mod. I had weak spark and fouling plugs before.

[GSCafe]

This mod is on my list. I had to clean up stator/rectifier issues before considering this. Make sure your system is already providing proper power from the non-battery components.

[mainiac]

I got a question regarding the relay ignition coil mod. So in my case I was measuring 9.2 volts at my coils. Way low. I am currently in process of installing the relay mod and I understand the original orange/white wire in the big bundle (which is where I had the 9.2 volts) will be powering the coil of the relay and the new clean 12v will be on a wiper of the relay. My question is - how low a voltage on the coil of the relay before you would see chattering on the relay ? I see you had 10.1 volts and apparently there is no chattering.

I excited to see the difference after the mod. I had weak spark and fouling plugs before.

I am not sure how low the voltage would have to be before it would cause problems to the relay. I read on here somewhere that it takes very little voltage to operate the relay. I am pretty sure 9.2 will work it fine. Hopefully some one who knows more about it will be along to give you a better answer.