Question-------------------------
Hi Chris
About the 87 Suzuki Intruder problem. The backfiring happens as I am downshifting to a lower speed. Lets say comming off a highway, or driving from a main road and turning onto a residential street. Not all the time, only once in a while. When It backfires it is not just popping it is two or three extremely loud bangs. Sometimes so powerful it stalls the bike. Does that describe the problem better. Also the ignition timing is unadjustable. It is controlled by an ignition modual.
AnswerHi Robert.
What you are describing is very common. What you are doing when you gear down to slow down is to force an advance in the ignition. That will cause backfiring. It should not, however, cause the motor to stall. Have you had the valves adjusted at the appropriate intervals? The problem could have an additional relationship to that as well.
By gearing to slow down, you are not harming the bike so much as accellerating the intervals betwen valve adjustments. Remember that any time you force something like the ignition timing, you are forcing all of the other related components to advance as well.
As I said, it will not harm the bike, but it will force you to do the required related tune-ups a bit more; this does include the carb synch as well.
As far as the engine stalls, it doesn't make sense that the issue is related to the backfiring. More likely, the problem is triggered by something that is happening when you do that. Possibly with carbeuration or electrical. Check for any shorted wires in the main power or ignition system that are not secured properly.
Good luck and ride safe.
FALCON
