Help! Bike shuts down while riding

Well guys, I think it is a venting problem after all. All new ignition did not help. What I think is happeningis as fuel tank can't vent properly, it may be forcing fuel down into the carbs fouling plugs. Just a theory, and I kow it was mentioned in the posts earlier.
I tried cleaning the stock cap because finding a used cap for an Sr is next to impossible, but to no avail. Finally one listed on ebay and I snagged it(should be here any day).
I'll try this, plus I put colder plugs in too just as another blind shot, Thanks for all the info and help so far.

Keep your fingers crossed....

What I think is happeningis as fuel tank can't vent properly, it may be forcing fuel down into the carbs fouling plugs. Just a theory,

If the tank can't vent, you get vapor lock. There is no way the fuel gets forced to the carbs to foul the plugs in this situation.

Are you using the coil relay mod? I just had my relay fail intermittently, and it drove me nuts with missing and finally dieing, only to start up later. A cheap chinese relay was the problem, I should have used a Bosch or Tyco. But to it's credit it did last 3 years.

rsrcafe wrote:

Well guys, I think it is a venting problem... tried cleaning the stock cap...to no avail....

Could test run with fuel tank cap ajar (not snapped down), which vents the tank regardless of whether the cap vent itself is clear or clogged.

If problem persists during test run with cap ajar, it's likely not resulting from a cap venting problem.

On the other hand, if problem disappears during test run with cap ajar, it likely resulted from a malfunctioning (i.e., clogged) cap vent.

Good Luck!