Boyer micro digital

chrispunk

XS650 Enthusiast
Messages
39
Reaction score
3
Points
8
Location
london
Hey guys, So I have a Boyer micro digital(photo below) on the 79 I’m builiding. It was a running bike until my mate crashed it 4 years ago. The problem I have is I don’t have the advance unit and don’t know if I need it. I haven’t taken it off my self (but I know some bits got borrowed for another build at one point.)

Any way that’s a long way of asking if I need the advane unit for this ignition?

Cheers

558D3817-8734-4AD1-8AEA-CE0AEE856A24.jpeg
 
Hi. The quick answer is No. The ignition advance is taken care of within the unit. As long as you have it wired as per instructions it will be OK. If you are unsure of the fitment, visit Boyer Brandsden website where you can view or download the fitting instructions for all their products.
 
Last edited:
Hey, thanks for that. I was pretty sure I didn’t but my mate who’s a mechanic(and generally knows much more than me) was adamant I did.
 
Mine came with a Boyer Digital unit fitted by a PO.
I'm impressed with how it starts from cold and immediately settles down to a steady idle.
 
Boyer products are fantastic I am very impressed with mine.
Saying that,... their website and product information and installation guides are confusing and f*cking useless
As far as I can make out from their website it would appear that the 2x kits they currently supply for the XS650 both include electronic advance . I imagine that very early Kits would not have included Electronic advance .How you'd tell the difference with no documentation is anybodys guess .

There are basically 2x types.
KIT 00303 (Micro Power ) has electronic ignition advance built-in and includes the high power coils ( 00004/6 )
KIT 00103 (Micro Digital) has electronic ignition advance built-in but does not include the necessary ignition coils ( 00004/6 )
The other 2x Kits (Red box & Blue box ) are spare Micro Power and Micro Digital boxes .

If you remove your advance covers and find original mechanical advance mechanisms fitted then you obviously have early non electronic advance units fitted. ;)

 
AFAIK all Boyer-Bransden ignitions have featured electronic advance. The early "black box" models advanced the ignition in 4 steps. The later Micro Digital ("red box") system and the more recent Micro Power ("blue box") system advance the ignition in a continuous curve. (Note: very early Micro Power boxes were red).
 
Last edited:
AFAIK all Boyer-Bransden ignitions have featured electronic advance. The early "black box" models advanced the ignition in 4 steps. The later Micro Digital ("red box") system and the more recent Micro Power ("blue box") system advance the ignition in a continuous curve. (Note: very early Micro Digital boxes were red).

depends how far back you go I think.
Early analogue boxes certainly didn't include electronic advance of any kind .

Reading the blurb on their site it seems that fully digital ignition systems with electronic advance probably started some time in the late 90's
As you say ,the Red and Blue box colours are currently used to distinquish between the Micro Power ignition system that uses the bikes OEM coils and the Micro Digital system that uses Boyers own high power coils although these boxes are also available seperately .
 
Last edited:
I just replaced the old Boyer ignition today with the new Blue Box Micro Power kit. The ingition I took off was a Red Micro Power and used the same coil as the new Blue one. The instructions said to set the initial timing at the full advance mark. In the YouTube video above the timing is set at the "F" mark ??? This is what I removed.
scrambler work 009.JPG
 
Normally Boyer systems are initially set with the rotor white dot central in the hole on the pickup plate, with the engine in the full advance position. 34/38 deg btdc. Then it should run, you can fine tune it with a strobe light, to suit your needs. The Boyer website gives all the info you will require. Hope it helps.
 
I just replaced the old Boyer ignition today with the new Blue Box Micro Power kit. The ingition I took off was a Red Micro Power and used the same coil as the new Blue one. The instructions said to set the initial timing at the full advance mark. In the YouTube video above the timing is set at the "F" mark ??? This is what I removed.
View attachment 115555

there was an error in the video which is detailed both in the description and in the notes below the video.
The Boyer should be set at the full advance mark which is the mark furthest from the TDC mark
 
Oops! Meant to write "Very early Micro Power boxes were red" (all Micro Digital boxes were red). Edited. Yep, initial sight timing is done at the advance mark as per Boyer's instructions. That usually gets you close enough to start up and inspect with a strobe. Sometimes it helps to ground the plugs, hook up a strobe, turn the motor by hand, and watch where the timing marks are when the strobe gives a single flash.
 
Last edited:
Thanks for the info. I did set the initial timing at full advance as per the instruction sheet. Hopefully this will get it started.
 
If the electric foot is installed and working, you can ground the plugs and spin the motor with it for an initial strobe reading. Maybe I should clarify: turning with starter or by hand, you're looking to set by the "F" marks before firing up and setting the timing at full advance (motor revved until timing advances to the max).
 
if thats a freshly built engine I wouldn't recommend revving it to max advance just yet ;):)

the Boyer is microprocessor programmed and controls the advance curve to minutes of a degree . As long as your TDC is reasonably close the engine should fire up and run perfectly . My inclination would be to let the engine run up to temperature a few times and re-torque, set the idle mixture & speed etc and put 100 miles or so on it before worrying too much about using a timing light to check TDC and if the Boyer is working correctly.
 
Understood. Thanks. The directions said the "F" mark was the Low Speed mark. I can`t imagine riding this for 100 mi??
 
You'd use the F mark only if you're using the strobe with plugs grounded and looking for a strobe flash turning by hand or spinning the motor on the starter. "Low speed" means low rpm and that's what you're turning with the starter. The Boyer box will advance the ignition electronically in response to engine speed.
 
I can`t imagine riding this for 100 mi??
not all at once :rolleyes: I guess I was saying if it was a new engine it would be better to put a few miles on it to bed the rings in and do a re-torque etc before revving the nuts off it ;)

I've always avoided revving any engine that weren't under load but its your engine

Anyway we are kinda hijacking Chris's thread arn't we !
 
Back
Top