Won't start

[john.nash]

Well.

I already swapped the petrol out for some that is in running bike. I'd swapped in a plug from a running bike too and regapped others.

I tried Paul's pencil thing with exactly the same result. Backfires through the carb but no start.

I ordered a spark tester off amazon, as suggested above, which rocked up yesterday. It's not ideal for kickstart bikes but nevertheless, I could see that I had a spark running up to the plug.

At this point, I'm down to substitution of parts and I know I have a spark under compression, so I started with the carb. I have a running vh with an older concentric, so I swapped them over. And ...

.... IT STARTS !!!

HA !!!!!! must have been the brand new Amal premier, all along. Just for kicks, I then put it on the other bike ..... WTF ... that bike starts as well and seems to run fine ( same jets and settings).
I've had that bloody new amal premier off multiple times before, messed with pilot jets and cleaners, and could find nothing wrong ....

I'm stunned. Maybe compression is slightly less on the new bike still and the new carb is sensitive to that ... who knows ... but it started when I came back from the pub last night and again this morning..

I'm still not trusting it entirely... this happened last week in that it just refused to start. Maybe the carb swap was a fluke and the electrical issue magically sorted itself ...

. and not sure this helps Gary, but that spark tester thing was useful.

[garycullen]

I have a spark tester , bought four of them for my 1933 Austin 10/4 when chasing down ignition fault with that project, but didn’t think about using one on the VB. I will try it and see.
One thing I am pretty sensitive to since working on the A10 is I had two new batches of NGK AB6 plugs with internal low resistance out of the box. Between 3k an 4K ohms. Common motor parts suppliers in Aus and NZ have been caught up in distributing copy NGK plugs.
I now buy from green spark plug co or the like.
The NGK plug currently in the VB measures infinity between centre electrode and the outside case so I am assuming it is okay.
So my steps are going to be:
Wire up HT lead copper wire direct to plug. Use spark indicator.
Source different manufacturer for 18mm plugs. Use spark indicator
Swap back to the Monobloc.
… such fun.
Gary
Antipodes