Honda-SOHC

On my 350F I set the idle screws 1 1/2 turns out then I used a 3mm drill on the engine side of the slides to set all the slides to the same height.

I used the large idle screw to open up all of the slides then used the adjusting screws on top of the carbs to equalise the heights (then remembered to wind the idle screw back again).

When I put the vac gauges on it and fired it up the carbs were so close that, were I not completely OCD, I could have left them alone. Only one carb needed a tiny adjustment.

If you buy the Boyer kit you will need their coils too as Boyer specify a minimum coil resistance of 4 ohms.

As I posted earlier you can use the DSS coils with the Boyer system but you need to wire a 1.6 ohm ballast resistor in series with the power (black) lead on each coil.

I posted a few photos about the Boyer system a couple of months ago so if you search under my user name you should find it.

http://www.sohc.co.uk/index.php/topic,8979.msg61594.html#msg61594

I've used Lumiweld rods with great success on lots of jobs.

The key to getting a good bond is to get the workpiece itself hot enough so that the filler metal melts when it touches the job rather than just melting in the flame. If the metal itself is not hot enough the filler metal just stays on the surface and scrapes off afterwards.

I welded this filler neck into my Moto Guzzi rocker cover using Lumiweld.

Not checked the resistance on the original coils yet, but the pair of Silvers replacements read 3.4 and 3.1 ohms. I am assuming this will be okay as I am running points. Is this correct. Cheers.

You should be OK with these. The points may burn a little quicker but you should be OK.

I looked at that but unfortunately my OEM system was the wrong type so I went for the Boyer set up.

How can all the plugs fire at the same time ?

If you look at the picture you will see that there are two pickups on the backplate, one for each coil. You will also see that there are two magnets on the rotor so both pickups are energised at the same time and both coils fire at the same time so all 4 plugs fire together.

Here's a section of the instructions.





I also emailed Boyer Bransden querying why they used this system.

"Can you tell me the thinking behind using two magnets on the rotor and firing all the plugs together rather than using a single magnet and firing the plugs in pairs like the OEM points system? Is it just a question of keeping the rotor balanced?
 
Does this system have any significant effect on spark plug life?
 
John Dickens"

........and this is their reply.

"Hi John, There are a few reasons. Its more accurate, once its completed one revolution, the system will find a central point for sparking and that will never change. Because of this, it makes setting up much easier and can be done on any cylinder. It also burns un-burnt fuel ready for the next firing stroke which improves the running and emissions of the engine."

I've just fitted the Boyer unit to mine. It works very well with smoother running and a smoother idle.

The hardest bit was finding a place for the electronic box.



Fitting the backing plate was easy once the advance retard unit was removed.



One thing to remember is that with the Boyer unit ALL the plugs fire at the same time whereas with the standard system they fire in pairs. This will wear the plugs faster than normal so it's worth checking them more frequently.