Ignition advance

[the mole]

I read on here recently that the GS ignition is 5 degrees advanced up to 4000rpm, and 25 degrees after that. Can anyone confirm that? If true, that would suggest that if riding around town it might be more efficient to stay just above 4000 than just below. I do a lot of riding at around 3000-3500rpm......

[twocool]

I read on here recently that the GS ignition is 5 degrees advanced up to 4000rpm, and 25 degrees after that. Can anyone confirm that? If true, that would suggest that if riding around town it might be more efficient to stay just above 4000 than just below. I do a lot of riding at around 3000-3500rpm......

The timing advance should be a smooth curve from 5 degrees and moving more advance as rpm increase.........if the computer is set up correctly, it should yield best effeciency/performance combo at any rpm......

You are suggesting that the timing curve is "flat" all the way up to 4000 rpm...........hmmmmm......I don't know for sure....
but 5 degrees seems to little for 4000 rpm..........my logic says if this is true that you should always drive above 4000 then, to get the advance which will improve performance, economy etc...

Just drive around however you like to.....

Someone on this group told me the advance goes from 5 degrees up to 40 degrees............25 seems like too little advance for say 8000 rpm.........

Cookie

[the mole]

Yeah, it was 40 not 25, my bad. I know some older bikes had ignitions that had an abrupt change at a certain rpm (my old Ducati was one), just not sure if the GS is/was the same.

[twocool]

Yeah, it was 40 not 25, my bad. I know some older bikes had ignitions that had an abrupt change at a certain rpm (my old Ducati was one), just not sure if the GS is/was the same.

Yeah, never seen the curve for the GS 500.......

Looks like you fly airplanes?  Tigermoth?

As you probably know, most airplane engines have only two ignition timing points...........usually zero degrees for starting the engine, and then about 23 degrees or so for everything else!

This works because airplanes are run at cruise rpm most of the time, and not thru a range of speeds like a car or motorcycle....This is also why airplanes idle kind of rough..........

Cookie

[Firewalker]

Have you guys done the ignition advance mod?  Seems like someone named Bob did those at one point...... Do you know which Bob it is?  Did you do it yourself?  Thanks in advance.  <------------teehee

[black and silver twin]

Its very easy to do it yourself, I did it, took about 20 min and was free!
very noticeable low-end gain and less-noticeable top end gain.