What exactly is controlled by the ignition box.

[The Buddha]

I am trying to determine if I should run the GR on the GS wiring harness and Ignition box, or run it on the GR's. The GR box isn't a direct plug in to the GS harness - dunno if color codes match and I can swap em wires and then plug it in ...
But ... can I run the GR motor with the GS'es Ignition box.
If not ... could a wire color code match and swap work from GS harness to GR ignition.
I actually heard that the ignition box only really controlls the spark advance. The virago guys said that actually and I've had nothing but trouble with the virago crap.
Cool.
Buddha.

[fred]

Hmm, I think if I wanted to know this, I'd try asking you... Now I'm all confused....

[The Buddha]

Baaaahhhhh hahahahahahahaha

I would think its the advance curve ... and not a whole lot else.
Virago black boxes are much more ... ahem ... open friendly ... and there is one guy who definetly says its advance curve only.
It will start and run with a bad black box ... OK will it run with a missing BB ... dunno ... google this name - David Denowh (or denowth) ... he is the virago BB master.
Cool.
Buddha.

[5thAve]

I'm pretty sure it's nothing but spark advance. I don't think it's sophisticated enough to alter the duration. Probably could run fine no matter what the spark duration anyway.

I doubt that color codes are going to match between bikes. Even two soozooks.

[The Buddha]

I thought duration is controlled by the dwell in the advancer nose.
The spark advance, I guess if the wire color codes to the coils and BB etc have some correlation they prolly can be swapped.
I know that cos I replaced a 88 virago 535 BB with a 82 virago 750 one. The 750 one was like solid state (the thing was 1/2 the size of your average laptop. 535 was IC based and it was more like the size of a cigarette pack. I had to mount it on the frame under that faux tank, it was that huge. but it worked after a wire pin swap, and I realise it may not have even needed that, I suspect the front and rear on the 2 were interchanged. Since they both use the same advance curve I could have left it well enough alone.
However ... a virago 1100 BB ... well I might as well attempt to swap mine, it got some unknown issue ... though @5K ignition advance pretty much has all been taken on ... its actin up @ 5K under load, stand and rev, it makes 7-8 no problem.
Cool.
Buddha.

[5thAve]

I think (but could be wrong) that the ignition rotor just times when the "spark" process STARTS. I think (but could be wrong) that it's resistance that determines the duration of the spark -- like higher resistance somehow leads to shorter dwell. Somehow just all that voltage being discharged an' comes a rushin' out. So basically, I really don't know what I'm talking about here and the bottom line is, I think the CDI box is early 80's technology and just controls the advance curve.

[Jared]

I'd go with the GS's CDI.... it fits the harness- the technology is from the same decade (ok so that's not the best argument for it....obviously the GS"s cdi being smaller is a sign of the improvements in CDI's..).
GR650 cdi's are probably harder to come by if you bugger it up (Gs500 cdi's are easy to get..).

I wouldn't think the  advance curves /etc wouldn't be much different between the two engines... displacement is close.  What was the GR's factory redline? Similar compression between engines?

Hmmmm

http://www.motorcyclespecs.co.za/model/suzu/suzuki_gr650_tempter%2083.htm

[The Buddha]

GR redlines @8500. I think its lower compression than GS.
The BB's on both are same/nearly same size.
Cool.
Buddha.