Boyer ignition fitting a lesson learned

[paulbaker1954]

I just finished fitting the Boyer system to my 4 but learned a hard lesson on the way that I thought I’d share.

The Boyer instructions say to remove the bob weighs and springs but do not make it clear you also have to remove the advance/ retard cam off the advance/ retard unit shaft as well.

I missed this and was confused as to why the stator plate did not fit properly and why the mag rotor fouled the chrome cover.

In my confusion I filed off the lugs on the end of the advance unit to get it to fit (unsuccessfully) without fouling the cover (thanks to Ash for replacement advance/ retard unit)

The answer was simple as always in hindsight, in that if you don’t take off the cam bush the stator plate won’t fit over the end of the advance unit properly and the mag rotor won’t fit over the end of the advance unit shaft.

It all comes down to a missing comma!!

Instruction 16 in the Boyer instructions says

“Remove the cam bobweights and springs from the advance retard unit”

It should say
“Remove the cam, bobweights and springs from the advance retard unit”

Amazing what confusion a missing , can lead to!!

As the saying goes

“Eats shoots and leaves” or alternatively “Eats, shoots and leaves”

I have notified Boyer by the way !!!

[mike the bike]

Missing capitals can also cause confusion,  as in;

I helped my uncle jack off his horse

I helped my uncle Jack off his horse

[Rozabikes Tim]

Missing capitals can also cause confusion,  as in;

I helped my uncle jack off his horse

I helped my uncle Jack off his horse

My wife feels it would be wrong to send my children into school with that to show their English teacher... Can see why?

[AshimotoK0]

Missing capitals can also cause confusion,  as in;

I helped my uncle jack off his horse

I helped my uncle Jack off his horse

My wife feels it would be wrong to send my children into school with that to show their English teacher... Can see why?

Send here in with this then. "Swim swan over the sea, swim swan swim. Swan swam back again, well swum swan". What the F is that to do with SOHC bikes  I haer everyone mutter ...Glad the auto advance arrived OK Paul.... nobody answered my query though ...Difference between CB500/4 auto-advance mechanisms  marked AD125-01 & AD125-02 (02 is marked '323' .... 01 isn't)

[paulbaker1954]

Ash
Have you checked if there is any difference with the max advance marks between 01 and 02

Just a wild guess

[deltarider]

Difference between CB500/4 auto-advance mechanisms  marked AD125-01 & AD125-02 (02 is marked '323' .... 01 isn't

Ash, I have no idea what you're talking about. Where are we supposed to find these numbers?

[AshimotoK0]

Difference between CB500/4 auto-advance mechanisms  marked AD125-01 & AD125-02 (02 is marked '323' .... 01 isn't

Ash, I have no idea what you're talking about. Where are we supposed to find these numbers?

Stamped onto the plate of the auto-advance !

Some info here:-

http://forums.sohc4.net/index.php?topic=113338.0
http://forums.sohc4.net/index.php?topic=113338.25

[deltarider]

Thanks, so it's about Hitachi only, right? The CB500/550 models came with two types:
30220-323-005 (Hitachi) and 30220-323-154 (Toyo). Mine are both Toyo (TEC) so that explaines why I couldn't detect a number. BTW, a member of the German site discovered that the springs varied in length between the Toyo and Hitachi advancers. Hitachi takes 20mm and Toyo would have 21mm springs.

[K2-K6]

That thread is really interesting Ash, I'd not seen that in the things I've read about ignition.

The post of Hondaman on 27th may 2017 is very pivotal to some of the discussion we've had on here about ignition systems. The length of spark is critical as far as I can see for these engines.

The various spec for advance mechs appears to be more tolerated on the 750 motors when used. Their sensitivity to that area is much more likely to have an impact on the smaller capacity engines and particularly when used on the 400. I belive it's this area that influences the detonation that's apparent on some of these engines.

[royhall]

Missing capitals can also cause confusion,  as in;

I helped my uncle jack off his horse

I helped my uncle Jack off his horse

I read this post this morning and am still laughing at teatime. Brilliant!!

[AshimotoK0]

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[K2-K6]

Don't know if it's just me but on those two Hitachi mechs the top dead centre T mark is in the same position,  but the F mark is moved from one example to the other.

This would give a different static timing start point,  and so different total advance also if the swing is the same for the two.

The 01 example appears to have something like a couple or 4 degrees more static than the 02.

[K2-K6]

Or looked at from the opposite direction ie the 02 came later if on the same engine,  then the ignition static setting is retarded.

Has the advantage of not changing the setup spec for a workshop, and manuals still being accurate regarding routine. It effects a change without being visible unless you have to replace parts.

Which bike is the 323 fitted to? as the other 3 look to be the same as each other.

[Seabeowner]

Couple of TEC 323 (500) advancers:

[Seabeowner]

Following up on the above, I found it difficult to find the spec for these, but internet info (treat with caution) seems to show:
300 (750) advancers:  10 deg static:  35deg fully advanced.
323 (500) advancers:    5 deg static:  30deg fully advanced.
I have a Boyer system that I picked up for £10 and presume as it uses the original (323 in my case) advancer back plate to set the timing, I presume that it is right for my 550.