21-10-2017, 06:55 PM
We had a similar situation with Dad's 1930 Triumph Super Seven, years ago we fitted a 1+1/8th SU to it as the old Zenith was badly worn at the butterfly shaft. Symptoms were just like spark breaking down - we rebuilt the magneto and the coil conversion twice each, to no avail. reset timing, checked compression, fuel delivery, swapped plugs etc, etc.
Turned out that the washer under the seat for the main jet had split and fuel was gushing out as soon as the needle lifted when trying to increase revs. This glut of fuel would wet the plugs and choke off the motor. Sometimes it's the simplest things that cause us the most headaches...
Cheers
Greig
Sunny South Africa
Turned out that the washer under the seat for the main jet had split and fuel was gushing out as soon as the needle lifted when trying to increase revs. This glut of fuel would wet the plugs and choke off the motor. Sometimes it's the simplest things that cause us the most headaches...
Cheers
Greig
Sunny South Africa