BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: MadPete on 17 Mar, 2025, 16:41

Title: Fitting B25 with Boyer ignition plate/sensor
Post by: MadPete on 17 Mar, 2025, 16:41
I'm about to fit an electronic ignition sensor to the timing side of my newly rebuilt B25 engine. I have already had to shorten the securing bolt by 1/8" so it can clamp the rotor correctly. Now to position the sensor plate.

There is an instruction to put the plate centrally in the adjustment slots, when the piston is at TDC. I suppose that "just works" and will allow subsequent timing adjustment. I will do that by default. But to save any potential bother are there any placement and mounting tips for installing the Boyer single system on a B25? I'd hate to have to find out the hard way. :0)
Title: Re: Fitting B25 with Boyer ignition plate/sensor
Post by: DAVE BRADY on 17 Mar, 2025, 17:40
Hi,

Don't the instructions mention a screw head on the rotor appearing in a hole on the stator?

Dave.
Title: Re: Fitting B25 with Boyer ignition plate/sensor
Post by: MadPete on 17 Mar, 2025, 19:02
Ah, yes... Line it up with one hole for clockwise and t'other for counter clockwise. I can see that would set an default angle.
Noted. Thanks. :0)

Does anyone who has used one think the crimp bullet connectors are sufficient or should I solder them? Or indeed solder the wires directly and shrink wrap them?
Title: Re: Fitting B25 with Boyer ignition plate/sensor
Post by: DAVE BRADY on 17 Mar, 2025, 21:56
Hi,

Some say solder is best but crimps do work as well.  I only use crimps and they work fine.

Dave.
Title: Re: Fitting B25 with Boyer ignition plate/sensor
Post by: iansoady on 18 Mar, 2025, 11:55
I hate those crimpd connectors wherever they appear. I always replace with soldered bullets: standard Lucas type for most but use Japanese ones for the Boyer PCB as space is limited in there.
Title: Re: Fitting B25 with Boyer ignition plate/sensor
Post by: MadPete on 19 Mar, 2025, 14:55
In my case crimping was instantly easier but lets see how it goes. I can always solder the connectors - or the joints.

I used the rank advance timing hole tool to set the crank position and then I set the rotor and stator plate. Not fired it up yet - I'll leave that until its a bit warmer out.

Thanks for the comments. Always nice to get confirmation one is doing the right things. :0)
Title: Re: Fitting B25 with Boyer ignition plate/sensor
Post by: iansoady on 19 Mar, 2025, 16:06
One of the reasons I went to soldered joints was a persistent misfire on my Commando duting a tour in France. I was convinced it was carburation but when it finally died on me I saw that the connector to the PCB had been flexing and there were only a couple of strands of cable left.
Title: Re: Fitting B25 with Boyer ignition plate/sensor
Post by: MadPete on 23 Mar, 2025, 11:19
Thanks for the feedback - I will consider what is best to do next week after examining it all. It seems to be that the solder method may be neatest with minimal internal components to fail and vibrate. But I admit the crimp method is quick. As I still have to do the crimping there remains a real choice!