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[vince]

Hi, when my coil failed it felt like a blocked jet in that the bike was running but died if the throttle was opened. Slowly it happened at lower and lower revs till it finally died all together. A condenser would tend to cause a misfire. Vince

[windmill john]

The coil was one of the first things I changed with my stopping fault and it wasn’t that. At least I have a spare coil. Only mention the plug cap as it’s cheaper than a coil.

[Harald]

Did you already change the spark plug connector ?
In the past I exactly had the same issue two times with two different bikes. The resistor inside the connector was corroded and when getting warm and under compression the spark was missing. Changing the connector cured the problem.
A faulty ignition coil can make the same mess.

[Clement]

Plan forward is to try a new ignition coil plus spark plug lead and cap while somebody who knows his way around with a multimeter will test whatever needs testing. Clement

[vince]

Hi, Just a thought had you filled up on the journey? Stale petrol. Vince

[Clement]

Vince - fresh petrol, new petrol tap, no issues with petrol cap (breathing), carb okay - must be the electrics I think. Waiting for assessment of the problem by somebody who knows his way around points ignition systems, alternator output, ignition coil (was tested on workbench and seemed to be okay but could be a different story when heating up), condenser, rectifier/regulator etc. In hindsight it would have been a good idea for me to become a shareholder of NGK. Will keep you posted on progress (or lack of it).

Cheers

Clement

[windmill john]

As mention above, just try a new plug cap; possibly plug too. If not rectified, new coil. After that, consult someone else as you mentioned.

[vince]

Does your ammeter show an excessive charge a defective regulator can overheat a coil .

[Clement]

No, charging but not excessive; my money is on the coil which in its turns wrecks the spark plug; thanks for pointing out what could be causing this overheating - I have a new spark plug, cap and coil ready and hope to find out more coming week. Clement

[Clement]

It took me a while to get on top of this; my money was on the electrics (ignition coil) but it turned out to be the carb after all: a worn needle jet; surprising as the carb was supposedly new and had only done 8,000 km. See attached pic - worn jet at left and new one at right. Note difference in circumference.

Clement