Adjustable Magneto Sprocket - For G80/S

Ramon518 · Post by **Ramon518** » Fri Jan 07, 2005 11:03 am

Hi everyone, - Blatant Advertising, for a purpose!!

I am waiting for one of the above to be manufactured by Martyn Adams at SERCO, 2 Bracken Road, Brighouse HD6 2HW - Tel 01484 715288.

I ordered it 1st August 2004 and have been waiting for delivery ever since, I AM NOT COMPLAINING ABOUT THIS.

However It occurred to me that as my order is only for a "One Off" at £41.13 including VAT, I might help the system along by publicising the availability of this fantastically useful two piece sprocket.

With it, small adjustments can be made to the Ignition Timing without the need to break the Taper joint - really helpful if you feel that your bike is running a bit too far advanced or retarded and you do not want the complicated, messy and generally unsuccessfull full blown method of re-setting the Ignition.
SO - Please, do yourself a favour and order one, you may (I hope) speed the process of manufacture for me and save yourself a lot of trouble in the future.
ALTERNATIVELY - I understand that in June 1982, or thereabouts, in the Jampot Magazine there was an article about a similar item but of a different construction - Does any body know what happened to that one and why are these things not more generally available??

Ray Brinkman

CR · Post by CR » Fri Jan 07, 2005 8:59 pm

Ray, the last time this was aired in the Jampot was July 1988 (Issue 552) where Bill Redford wrote (with photos) to show a piece of kit made by Chris Askham of the Fenrunners. It consisted of an original lower mag drive sprocket with 13 holes bored and a loose sprocket with 12 holes bored. Effectively it provided ignition adjustment in 2.5 degree increments.

I've no idea whether Chris Askham went into production. Maybe a call to the sec of the Fenrunners might turn up some further info.

Merlin · Post by **Merlin** » Fri Jan 07, 2005 11:04 pm

Hi Chris,
What are these ere dgrees last time I timed a bike(in my youth)a bit of something down the plug hole marked at T.D.C then whatever before seemed to work OK.
Only joking but it did work for us.
Cheers
Stuart[:D]

itma · Post by **itma** » Sat Jan 08, 2005 11:13 am

bull**** baffles brains
[ancient engineers proverb]

Ramon518 · Post by **Ramon518** » Thu Jan 13, 2005 10:46 am

While I acknowledge the brilliance of the last two posts, I feel that they might have missed the point.

When having set up the ignition to the best of your ability (and who knows if its then right) by the book, out on a ride and you sense/hear that the engine is labouring - Flat or pinking.
This could be caused by a series of conditions - the Magneto Gap might have altered due to build up on the points, the fuel you have purchased in a different part of the country might have a different flash point, may also be contaminated leading to carburrettor adjustment required, the barometric pressure might be higher or lower, the relative humidity varies throughout.
All of these can lead to small adjustments as you ride.

When you get home - its all change again.

At least with the adjustable sprocket, a 2.5 degree adjustment forwards or backwards is easily made and you know when next riding that the ignition point IS Definitely Advanced or Retarded over that when you last rode the bike and you can look elsewhere if you still have problems.

Ray Brinkman

Merlin · Post by **Merlin** » Thu Jan 13, 2005 9:15 pm

Ray being a simple chemist the thing I like about old machinery is it's simplicity why complicate the job[?]Best of luck
Regards
Stuart[:)]

itma · Post by **itma** » Thu Jan 13, 2005 9:46 pm

Theres this little lever on the left handlebar that I wiggle about to do the same job.
Consider...on my old 500 the original advance was recommended 1/2" BTDC, but for most of its life it ran at 7/16; after some recent overhaul it is now at 3/8" it will still kick back enough to impress onlookers, but there is no discernable difference in performance,save it feels a little less harsh, this could equally be the result of other things I did at the same time.
If you increase or decrease the points gap you will also alter the advance/retard by 1 degree each 1 thou`. so you have to be a sensitive soul to notice the difference. I`m blowed if I could, but then I`ve got that little lever......
As I`ve read some of the comments on this site I can`t help but wonder how much enjoyment of these old bike of ours is lost by people trying to impose modern ideas and standards on to them.

suck, squeeze, bang, blow....and a flamable substance thats about all they need, if you can set light to it, it`ll run on it as long as its got a big fat spark, if not, take the suppressor cap off, I bet you`ve got one on.