BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: johnjag on 29 Sep, 2021, 08:59

Title: A65 running on.
Post by: johnjag on 29 Sep, 2021, 08:59
Hi all - I have a problem which I have heard of but never experienced in all the bikes I have ever owned, until now. I have recently purchased a 1964 A65 Rocket. 12 volts, fitted with a Pazon electronic ign and dual coil. The bike starts and runs fine but when I switch it off it always runs on for about 5secs, sounding not too good. Now I know most of the causes like red hot carbon in the head etc but as I have very recently had the head off and it is spotless inside this is not the cause. I have checked that the ign is actually switching off and the ign timing etc, fitted a cooler plug but now I am running out of ideas. Now when I say it is running on, I don't mean it just continues to run fine but its still firing but very erratically making the engine thud. Any more ideas for me to try please?
Thanks

John.
Title: Re: A65 running on.
Post by: tige on 30 Sep, 2021, 13:49
Only thing i can suggest, from similar issues with other bikes, is make sure all the earths are good and you have good continuity from A to B.
Title: Re: A65 running on.
Post by: johnjag on 30 Sep, 2021, 18:23
Thanks tige - well worth checking.
John.
Title: Re: A65 running on.
Post by: LightningAndStarfire on 30 Sep, 2021, 19:55
Perhaps a good idea to find out whether there are sparks from the plugs or a hot spot in the combustion chamber causing this. There used to be spark plug hats available with a window to observe if there is a spark in the lead, the idea is that there is a gap in the lead (with the window surrounding) for the charge to pass before the second gap at the plug.