Ignition timing on '79 GS850

[gssuzukixxx]

'79 GS850:

When setting timing with a timing light, engine idling at about 1200 RPM there is not enough adjustment in the backing plate slotted holes to allow timing to be set back to the "I" to the left of the "F". The best I can do is have the "1" in "1-4" line up with the stationary mark.

Is there a solution? The bike runs nice but is this too advanced for safe running?

Thanks
Brian

 

[Nessism]

I'm not sure exactly but you may need to gap the points a little more. Worth a try anyway.

 

[gssuzukixxx]

I'm not sure exactly but you may need to gap the points a little more. Worth a try anyway.

Well Nessism, you were right on with checking the points gap. I thought I had done a pretty good job when I set them awhile ago but they were way too wide.

This time I took a .013" and a .014" feeler gauge out of my set and set them so the .013" was loose while the .014" had slight friction. I made sure that this was the case at all spots along the cam. It took some time but I got them set.

Having done that I checked timing with the timing light and the timing had to be advance a bit to get to the mark the the left of the F lining up with the stationary mark.

Thanks for you help.

Brian

 

[Nessism]

Sounds like I was in the neighborhood with my advice, only exactly opposite of what you needed to do. At any rate, glad the bike is sorted out.

 

[Steve]

Are you trying to get it to fire on the "I" or the "F"? :-k

It is my understanding that the "I" is TDC, the "F" is for FIRE.

.

 

[gssuzukixxx]

Are you trying to get it to fire on the "I" or the "F"? :-k

It is my understanding that the "I" is TDC, the "F" is for FIRE.

.

I was trying (and now have it) firing on the mark to the left of the "F" at idle (As in "I F 1-4 I"). When I rev it up the mark to the right of the 4 aligns with the stationary mark. I'm pretty sure that is how it is suppored to go.

There is another mark to the left of "I F" that is TDC. So all the marks are as follows:

I I F 1-4 I
(TDC) (IDLE) (REVed)

Brian

 

[Steve]

Yep, sounds like you have it now. :clap:

.

 

[Crescentius]

You got it. The second mark is the "advance" timing mark, and should get closer to the reference mark as the roll the throttle. And yes, physically moving the points themselves is like a "wide" adjustment and the plates are a "fine" adjustment.