Quits running after slight warmup.

[yamdude]

I have my newly acquired 78 XS650 finally running. What I have done so far:

Removed and cleaned carbs, old intakes and no filter boxes installed yet

New points and static timed.

Adjusted timing chain

Clean fuel from a aux fuel supply with clear lines to observe flow.

The bike starts pretty easily and idles. In trying to time with a light, the bike begins to warm up and then has a raise and lower on idle and then stops running and does not want to restart.

I have a brand new 12N14 battery that is fully charged when I begin to try to adjust timing.

Do these bikes have some type of issue with stalling after slight warmup? I have not checked if the bike is charging on it"s own.

Thanks for any insight on this. I'm sure I'm missing something.

[yamdude]

Solved. I replaced both sp wires and installed new ngk plugs, all good.

[thatguy]

Nice. My first suggestion would have been to check valve lash. I also removed my carbs and cleaned them, plus installed new seats and needles, but I forgot to set float height, so they are coming off for that, plus I got new carb mounting rubbers and gaskets. I did have it running and it has such a nice smooth idle, plus revs responsively. I did notice that the tach is VERY slow to respond, but it seemed to loosen up a little. I had to replace the fuse box on it, as the previous owner (PO) destroyed it. I got one off an XS400, same thing, only it plugs in to a connector, so I left a few inches after the connector and soldered it in. Works perfectly.