Marlboro750
CB750 Member
Hello, im wondering if anyone can help me source the issue on my bike
so randomly the bike would start backfiring under acceleration between 3-4000 RPM.
installed new iridium plugs and it was fixed no more backfiring or sputtering.
it never ran so good in its life!!
Than... day in a half later it started backfiring again
i got the carbs synced and the idle improved but issue still remained
removed carbs for further diag
found a small pinhole leak in the accelerator pump
replaced that and still the same
my question is why did it run amazing with new plugs than shortly after go back to running like garbage
the plugs weren't fouled either
i replaced the wires as well due to age and misfiring in the rain
but i never changed or tested the caps
so randomly the bike would start backfiring under acceleration between 3-4000 RPM.
installed new iridium plugs and it was fixed no more backfiring or sputtering.
it never ran so good in its life!!
Than... day in a half later it started backfiring again
i got the carbs synced and the idle improved but issue still remained
removed carbs for further diag
found a small pinhole leak in the accelerator pump
replaced that and still the same
my question is why did it run amazing with new plugs than shortly after go back to running like garbage
the plugs weren't fouled either
i replaced the wires as well due to age and misfiring in the rain
but i never changed or tested the caps