Possible coil problems?????

Hi
Possible coil problems on a 1975 250 desmo 12 volt conversion. Engines stutters to a halt after about 5-10 miles (just far enough from home to be a nuisance) then usually restarts after it cools down. Coil gets very hot to the touch.
coil PVL 101 220 12volt
testing with a digital meter gives 4 ohms (on 200 scale), 6 ohms (on 2000k scale) so possibly that means 6,000 ohms.
Anyone else have a clue what might be wrong?
Happy riding to all.
iain@meek.demon.co.uk

Have found this---- “I have a PVL coil that I tested for comparison 3.6 ohm, 5.5 kohm. and primary resistance, generally 3.2-4 ohms. Secondary restance should be 8000 ohms or higher if possible.”
forum.classicmotorworks.com/ind … ic=21156.0 but this is all about Royal Enfield Motorcycles.

and

Secondary resistance divided by primary resistance gives effective turns ratio.
times voltage gives volts spark.
Generally, 20000v output is bare minimum, and that’s weak. Typically we would like to see 30000v spark, and 40000v would be real nice.
16000v is not good.

and

Lucas 3.2 ohm , 7500 ohm, giving 28100v (at 12v)
PVL 4.1 ohm, 6300 ohm, giving 18400v (at 12v)
Pertronix 3.4 ohm, 10300 ohm, giving 36400v (at 12v)

Maybe you are being too analytical!
It is often said that coil problems show up when they get hot.So the simplest diagnostic route is to fit a new coil.

Then even if the fault happens again, you know it is not the coil.

I would change the condensor (capacitor) while I was as it.

Of course if you change two things at once a Platonic realist would say you will never find out what was really wrong.

Against that, you may get a bike that is working!

Andrew


Oiain@meek.demon.co.uk LikeComment View on Facebook Edit Email Settings e coil
problems on a 1975 250 desmo 12 volt conversion. Engines

ohms. Anyone else have a clue what might be wrong? Happy
riding to all. iain@meek.demon.co.uk Like Comment
Facebook Iain T S
Meek and Gary Jenkins
posted in Ducati Owners
Club GB. Iain
T S MeekJune
20 at 3:46pm Hi

Possible coil problems on a 1975 250 desmo 12 volt
conversion. Engines stutters to a halt after about 5-10
miles (just far enough from home to be a nuisance) then
usually restarts after it cools down. Coil gets very hot to
the touch.

coil PVL 101 220 12volt

testing with a digital meter gives 4 ohms (on 200 scale), 6
ohms (on 2000k scale) so possibly that means 6,000 ohms.

Maybe you are being too analytical!
It is often said that coil problems show up when they get hot.So the simplest diagnostic route is to fit a new coil.

Then even if the fault happens again, you know it is not the coil.

I would change the condensor (capacitor) while I was as it.

Of course if you change two things at once a Platonic realist would say you will never find out what was really wrong.

Against that, you may get a bike that is working!

Andrew


Oiain@meek.demon.co.uk LikeComment View on Facebook Edit Email Settings e coil
problems on a 1975 250 desmo 12 volt conversion. Engines

ohms. Anyone else have a clue what might be wrong? Happy
riding to all. iain@meek.demon.co.uk Like Comment
Facebook Iain T S
Meek and Gary Jenkins
posted in Ducati Owners
Club GB. Iain
T S MeekJune
20 at 3:46pm Hi

Possible coil problems on a 1975 250 desmo 12 volt
conversion. Engines stutters to a halt after about 5-10
miles (just far enough from home to be a nuisance) then
usually restarts after it cools down. Coil gets very hot to
the touch.

coil PVL 101 220 12volt

testing with a digital meter gives 4 ohms (on 200 scale), 6
ohms (on 2000k scale) so possibly that means 6,000 ohms.

Coil changed for a Lucas 17M12 from montysclassicmotorcyclesshop.co.uk- working well again.

Many thanks to Andrew for his wise advice.

Iain