Spark Plug Gap

[mixongw]

Simply amaqzing that I can't find this info somewhere!

BIKE: GS1100GLD
PLUG: NGK B8ES

What should the gap be?

[Nessism]

I don't know although I’m sure it’s in the factory service manual - 0.028"?. I just install them straight out of the box and don’t give it another thought.

[bwringer]

I'm pretty sure it's .031" (0.8mm).

And that has been exactly where every new B8-ES plug I've ever installed has been set from the factory, so I don't bother to measure anymore.

[Larry D]

The manual for my 81 750 L from BikeCliffs site says;

.6-.7 mm
or
0.024-0.028 in.

[bwringer]

The manual for my 81 750 L from BikeCliffs site says;

.6-.7 mm
or
0.024-0.028 in.

Yeah, maybe that was it...

I don't remember any more -- like I said, I used to look it up and measure every plug, but after a while you realize they're all set just fine from the factory.

[jknappsax]

Can't you open up the gap to about .034" if you've gone over to an aftermarket coils and an electronic ignition (like a Dyna S)? Should get better combustion.

[hikermikem]

Simply amaqzing that I can't find this info somewhere!

BIKE: GS1100GLD
PLUG: NGK B8ES

What should the gap be?

My GS1100GD factory manual says:

0.5 - 0.8 mm (.020" - .031")

and there you have it...

[mixongw]

My GS1100GD factory manual says:

0.5 - 0.8 mm (.020" - .031")

and there you have it...

Thanks!

Out of the box maybe fine but I guess I'm kinda anal when it comes to the bike.

[lucabond]

I second the question about opening the gap if you have installed an aftermarket ignition. Has anybody done this? Will it give you a better spark? Thanks for any answers.

[lecroy]

I second the question about opening the gap if you have installed an aftermarket ignition. Has anybody done this? Will it give you a better spark? Thanks for any answers.

Yes you can and yes I have...

Normally though the ignition was put on to fire the plug with the higher compression pistons, or the turbo.... I have heard many people closing the gap with the aftermarket ignition just to make sure the fuel would ignite. MSD posts some numbers on how much the gap could be increased with their products. Not sure if Dyna and Schnitz post those numbers. Would very on the setup anyway.

[lucabond]

Thanks Mark. I put in a Dyna 2000 to replace a failed ignitor. I did open them up to .034 and it fires just fine thought I'd see how it worked. I have done the coil mod already and I replaced the coils with 2.2 ohm ones. I'll ride it for a while and see how it goes.
Paul

[jknappsax]

Since the early GSes were points-and-coil, and the coils were a little low on output voltage, changing the coils to higher output ones, like Dyna greens or Accel give greater output voltage, thus stronger spark. Opening up the gap should help with complete combustion. The post-1980 GSes used ignitors, so it probably wouldn't do much.