After rebuild, timing ignition

phliper · Jul 11, 2017

Hi all,

I tryied to start my norton after a complete rebuild. The engine was not rebuild, only the bike/carb got clean.

So the bike started on the 10th kicks, but I got a hard kick back. I almost hurt my foot. I did research and found that it was a timing problem, but i coudn't find any information on how to time the ignition except by starting the engine and get the rev a 5000 rpm.

The engine is not starting, i only got the kickstart lever back hardly.

Can you send me a procedure on how to time the ignition?

Regards,

Phil

L.A.B. · Jul 11, 2017

It would help if you said which "ignition".

I assume you mean electronic, so which make and type?
Electronic ignition manufacturers often have instruction sheets on their website.

Here are the instruction sheets for Boyer Bransden (all).
http://www.boyerbransden.com/instructions.html
And Pazon Sure-Fire
http://www.pazon.com/files/PDF/PA2.pdf
However, if it's another make/type or you aren't sure, then please say what it is or give more information.

Edit:
Checking back through your old posts it seems to be a Boyer Micro MkIII

MKIII & MkIV instructions
http://www.boyerbransden.com/pdf/KIT00053.pdf

1up3down · Jul 11, 2017

as LAB referred to the instructions, you will need a strobe light and an assistant to increase the rpm's to fully advance around 5000 very briefly so you can hold the strobe light to see around 30 degrees inside the small front primary cover area

because you say it kicked back hard this indicates your timing right now is too advanced and needs to be retarded

kommando · Jul 11, 2017

A low battery voltage can give you over advanced timing depending on which EI it is.

phliper · Jul 11, 2017

L.A.B. said:
It would help if you said which "ignition".

I assume you mean electronic, so which make and type?
Electronic ignition manufacturers often have instruction sheets on their website.

Yup, Boyer electronic ignition. Thanks for the link.

L.A.B. said:
Edit:
Checking back through your old posts it seems to be a Boyer Micro MkIII

MKIII & MkIV instructions
http://www.boyerbransden.com/pdf/KIT00053.pdf

I'll check that too.

cheers!

Mark Savage · Jul 11, 2017

I found this useful with Boyer ignition.

kommando · Jul 11, 2017

Boyer MK3's kickback with low battery voltages, check your battery is fully charged.

cliffa · Jul 11, 2017

Dommie Nator said:
I found this useful with Boyer ignition

I should say that is very useful indeed !! The Boyer units are not programmable so in theory should all have the same advance curve. Therefore setting the 1000 rpm to 6 degrees, then blipping up to 5000 to check the maximum advance is correct has got to be easier hasn't it?

Should this be added to the tech page ?

Cheers & thanks,

cliffa

acotrel · Jul 11, 2017

Some Boyers are programmable. However I always set the static timing first. You have to know where the pick-up has to be to fire the unit in the first instance and set it so that it is firing at the normal 29 (?) degree advance. That way you can start the bike and then use a strobe light and degree disc to see what the unit is doing - then move the stator plate to suit what is best for you. From memory, if you inadvertently reverse the pick-up leads on a non-programmable Boyer, you can end up with a big error in the timing.

cliffa · Jul 11, 2017

acotrel said:
Some Boyers are programmable. However I always set the static timing first. You have to know where the pick-up has to be to fire the unit in the first instance and set it so that it is firing at the normal 29 (?) degree advance. That way you can start the bike and then use a strobe light and degree disc to see what the unit is doing - then move the stator plate to suit what is best for you. From memory, if you inadvertently reverse the pick-up leads on a non-programmable Boyer, you can end up with a big error in the timing.

Hi alcotrel, Yes I should have said for those which not programmable, and of course once you have set the static timing following the setup guide so you can start the engine. Timing lights don't flash much when you are kicking an engine over

L.A.B. · Jul 11, 2017

cliffa said:
Dommie Nator said:

I found this useful with Boyer ignition

Click to expand...

I should say that is very useful indeed !! The Boyer units are not programmable so in theory should all have the same advance curve. Therefore setting the 1000 rpm to 6 degrees, then blipping up to 5000 to check the maximum advance is correct has got to be easier hasn't it?

The timing scale only reads down to 16 degrees. :wink:
The boxes don't apparently all have identical advance curves.

http://atlanticgreen.com/boyerevolved.htm
"Boyer MK III Production variations"

Checking the advance at various RPM settings also relies on the tacho being reasonably accurate.
Personally, I just start up and check at whatever the max. advance figure is for that particular ignition system.

Mark Savage · Jul 11, 2017

I used the INOA guide on my Dommie where there is no scale at all so I scribed my own on the rotor (not that I would trust the scale on the Commando anyway as they aren't always accurate). We're not all God's gift to motorcycle mechanics with spacious workshops and cooling fans so setting at a lower RPM for me is less fraught as I live in a terraced house with neighbours who have dogs and my own dog that runs and hides every time I even start it up. So I used 3000 rpm to initially set it and then a quick check at the recommended figure of 5000 rpm to confirm.

BTW, I've wrongly credited the INOA with this and I should've said this was written up by Perce Butterworth for Norton Owners Club of NSW.

(I hope he doesn't mind the repost here).

cliffa · Jul 12, 2017

L.A.B. said:
The timing scale only reads down to 16 degrees. :wink:

Ah, yes, I can see that may cause an issue

Interesting that the curves are not the same though.

acotrel · Jul 12, 2017

There are two things that work together, the advance curve and the shape of the needles in the carbs. If you use fixed timing and jet to it, you remove the complication but don't necessarily get the best performance. With petrol as fuel, you have a problem - it is very unforgiving of tuning errors. With methanol fuel, you have twice the margin for errors. So when I race, that is what I always use - it avoids the necessity of a lot of fiddling with jets and timing.

After rebuild, timing ignition

phliper

L.A.B.

Moderator

1up3down

kommando

phliper

Mark Savage

kommando

cliffa

acotrel

cliffa

L.A.B.

Moderator

Mark Savage

cliffa

acotrel

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