B31 cutting out - could it have been the points?

[Fraz]

Since I bought my '54 B31 in October, I've been having random cutting out and not re-starting issues, often moaned about on here.

New to the old 4 strokes, I was at a loss and many people said it sounded like condenser or magneto failure.

I took advice and bought the Thorspark electronic ignition, as a cheaper option than a magneto refurbished.

Took the bike round to a friend who knows how to do "stuff" and if set about checking the timing and points to make reference marks before fitting the electronic ignition.

He found my points were at 6 thou (instead of 18 to 20) and he swore blind that the points was my running issue.

How true could this be? (Out of interest)

The bike would run for 40 miles some times but them other times, only half a mile, before cutting out and only re-starting after several huge prods on the starter and flames shooting out of the exhaust.
Sometimes it would then be OK but mostly it would only run for a few yards before stalling again.  Once started, it would also stall / die as soon as the clutch started to bite.

Long story short, we fitted the electronic ignition and have now got to road test her but curious as to what people think about the points.

I'll post photos of where it was fitted, in a separate thread, just to assist anyone wanting to do the same.

Thanks

[iansoady]

Points for magnetos (assuming M01 magdyno type) are generally .012". .006" would definitely cause a problem - although not necessarily the one you encountered... .018 - .020 is too wide.

Plug poiints when using a mag are also usually .018" rather than the .025" for coil ignition.

[rhyatt]

Magnetos should never have a resistive plug cap

[Kernowpete2]

How's it running Fraz? Don't keep us in suspense!

[Fraz]

It's running great now - electronic ignition is the way.
Problem solved (it could've been the points gap or condenser but who cares, my bike is working now)

[V500]

I'd care....if I fitted EI and all it was was the points gap.

[Kernowpete2]

It's running great now - electronic ignition is the way.
Problem solved (it could've been the points gap or condenser but who cares, my bike is working now)

Excellent news 

[iansoady]

That's all very well but it means you have to have a decent battery and charging system...... I'd prefer a magneto in good nick myself.

[Kernowpete2]

For Christs sake - Fraz has been at his/her wits ends with this.

[Kernowpete2]

I thought this forum was about helping people not picking holes

[neil1964]

Glad you got it running and you can actually ride it.
Does your Dynamo work properly or are you doing short runs using battery in total loss mode?