Pazon EI - very weak spark ? | Norton Owners Club

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'72 Commando 750 (Combat)

I only get a very weak spark with a Pazon EI (you need magnifying glasses to see it!). When the bike is running, it runs very well (although I'm only in a breaking in period and haven't exceeded 3800 rpm).

I have a Pazon Surefire (circa 2019) EI with Tec KP02 coil. I've tested the crank sensor with Pazon's test routine of directly connecting the black white, yellow white cables and get a weak spark. I've tested that I have full voltage from the ignition barrel to the control unit and that is fine too.

Any ideas? Should I just replace the coil? Its not a typical twin lucas system - I'll attach photo.

Would be nice to get a big strong spark the way it should. That way I can eliminate that from my worries when I'm kicking it over!

Cheers

Attachments

IMG_5260.jpeg

fooled

I was fooled by thinking I had a weak spark also.
Fitted a new coil which made no difference.

Then I read the fault finding info:

Sparks from high power systems look different from old points based systems, they are very focused (hence appear "thin") and lighter blue (hence barely visible).

In addition to Gordon's…

In addition to Gordon's remarks, don't forget also that with a twin output single coil, you are effectively sharing the strength of one coil across two spark plug gaps.

By nature, this will also change the appearance to the naked eye - sometimes you may have to close down the gaps accordingly.

Ah Gordon! You may have…

Ah Gordon! You may have prevented me from setting a few expensive hares running! That would explain why it's running so well. Starting must be something else - its the old '90% of ignition problems are with the carburettor...'

Thanks Grant. I'll see how…

Thanks Grant. I'll see how it goes.

cheers

Mick

Reluctance to start when…

Reluctance to start when cold is very often caused by insufficient temporary enrichment of the mixture, by ticklers or chokes.

Thanks Michael, yes - just…

Thanks Michael,

yes - just want to eliminate the spark as an area of concern.

This bike is on Amal 932's with no air choke. After a good few miles of 'running in' the idle speed was higher than it was so I reduced the idle speed. I think that would have weakened the mixture - so checking air pathways and idle settings this morning, but I expect that will open another can of worms! Before that it was second or third kick... so back to those settings.

Weak spark?

Is what you see, the spark, a function of duration? I've noticed that with the BTH electronic magneto the spark is very difficult to see because of the short duration of the spark.

Thanks John not the duration…

Thanks John

not the duration especially, I'm used to a big fat blue spark and usually an audible 'tick'. What I'm getting is a very thin barely visible spark... to the untrained eye you would say it was 'weak'. Mission today is to try and film it!

Went back to basic settings…

Went back to basic settings on the carbs and adjusted until she starts first or second kick.

Thanks to the wisdom of the forum it save me going on a wild goose chase of looking at replacing ignition coils.

Enrichment - found that she likes a tickle on one carb to start when warm - two seems too much, but I expect things to change as she continues to run in.

I even managed my first few starts off the side stand!

Thanks all

Mick

Some basic facts are wrong

Yes basics-ALL petrol engines with carburettors need enrichment to start from COLD, IF the carburation is correct. Starting enrichment will be closing the air slide(choke) and some tickling. IF you do too much tickling then you can easily 'soot up' a plug.
If you have to close the spark gap to get a spark then the power to the plug is lower than it needs to be for starting.
Starting always takes more spark power than correct running. ie you have a cold engine and a 'rich' mixture for starting.
Magnetos have smaller plug gaps as they have lower spark energy than coil/electronic ignition.
Starting technique is another thing to learn.
Back to this particular problem-no air chokes=no start!

Thanks for your input Alan…

Thanks for your input Alan.

Put another 150 'running in miles' on her today - so up to about 400 now. Started first or second kick all day including from cold this morning, and starting well. Caused some amusement in a packed Helmsley square bike park by starting her up and setting off some car alarms!

So no air choke working ok for me so far - after lunch it was a cold start (in the rain) in Castle Barnard at 9c. Can see that I may be fitting air controls for the colder months.

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Pazon EI - very weak spark ?