Db18 spark mystery

[Db n j]

Been puzzled for a while., as the previously sweetly running engine seems off.

Main concern is that no1 doesn't seem to spark.

Did a few trials with a new spark plug cap, lead, and distributor cap to no avail. Each time, no spark at the
Plug.

Finally, took off the distributor cap and with ignition on, cranked the engine by hand and observed 5 sparks per rotation, nothing at no1

No perseived eccentric wear, no obvious problem with the cam lobes.

In desperation, dragged a spare distributor from the loft, cleaned, checked the points were in excellent nick.

Swapped.

Result, all 6 plugs firing.

But why. On the bench the old unit seems fine, and rotating the cam produced a wave of six open and close actions
at the points.

What could be the root-cause ..?

[grahamemmett]

The Spark Fairy was having a lark at your expense.......

Or in reality, it's 70 years old and sh*t happens. Lucky you had a good spare though.
Amused me it was in your loft as that's where all my spares are too.

[Db n j]

Graham, sounds about right.

As for spares, we have a loft, and a garage, but I have always worked on the basis that no one will keep all the bits you may need for your car, unless you do.

We were lucky in that the dizzy was actually really good, even the points were like new, despite the look of a dirty bit of scrap. It came from a guy who claimed if they weren't bought, he was going to scrap them !

On to the next bit of restoration

[grahamemmett]

Dave, me too. Recently found a brand new kingpin in a box of 'scrap' parts which is now on the car.
Have you signed up to www.DB18.org as there a spare parts for sale/wanted page there, the idea being we can trade with each other..