1977 XS650 - Ignition Timing Problem With Right Cylinder

[BlueR32]

Hi all, I checked the ignition timing on my recently acquired 77 XS650D. I did the Right side first per the manual and it was way off past the T mark. I turned the baseplate as far as it would go clockwise to get it to the F marks but I can't get it closer than the T mark. Any ideas?
Thanks!

 

[Jan_P]

Someone else knows this better than me it was a long time since I had points
The whole adjustment plate can be moved so both points are affected
But there is also one adjustment so one can be moved only

But first better service the advance regulator / unit

 

[MaxPete]

The procedure to set the ignition timing on an early XS650 is a little complex and it can get confusing.

I know that it sounds really obvious - but if you just sit down beside the LH side of the engine and really stare at the points mounting plates (there are two of them) you will readily understand the timing procedure.

The points for one cylinder are mounted on the big round plate and the points for the other cylinder are mounted on a smaller plate that is in-turn mounted on that big round plate.

Pete

 

[member43148]

The Mechanical Advancer mechanism under the chrome cover opposite side of the points is a known factor in setting timing. Look, carefully feel that the advance weights do move easily and return to the resting position.
That shaft through the head does need to be properly cleaned and lubed if the advancer doesn’t move correctly.
Good luck

 

[Westfalia]

We have a '78 SE with this exact issue. Watching.

 

[Melnic]

I learned a lot about points on my XS650 recently that I had forgotten for decades since working on points cars & motorcycles in my teens
Points gap (Dwell) affects the timing.
If you set a larger gap (shorter dwell), it will advance the timing (I think I got that right?).
Set your gap/dwell.

If you read on this site also, some other things affect it such as cam chain stretch and pitted messed up timing cam surface . (what the points ride on).

I set my static timing not with a light bulb but a volt meter set to continuity and I unplugged the points from the harness to make that work.
Here is a video on using a light bulb. as well as with it running. (one day I'll do a video on that).

I invested in a timing light and a cheap Amazon digital dwell meter (4 cycl and you have to do some math to convert).

Ultimately, I had to replace my cam chain from the stretching but also my front guide was delaminated. One COULD dremel the 2 notches in the cam plate but you are masking the problem if the cam chain is stretched. Besides if cam chain is stretched, your valve timing will be off some too possibly robing some power?

 

[BlueR32]

Thanks for all the great information, most helpful.
There's a lot to unpack here so I'll report back in due course.