The Spares Company
Club Shop/Regalia
Parent Website
Contact Officials
Machine Registrar
Club Secretary
Membership Secretaries
MPH Editor and Forum Administrator.
Section Newsletters
Technical Databases
Photos
Home
What's new
Latest activity
Forums
New posts
What's new
New posts
Latest activity
Information
Bike Modifications
Machine Data Services
Manufacturers Manuals
Spare Parts Listings
Technical Diagrams
Whitakerpedia (Vincent Wiki)
The Club
MPH Material Archive
Flogger's Corner
Obituaries
VOC Sections
Local Sections
Local Section Newsletters
Miscellaneous
Club Assets
Club History
Club Rules
Machine Data Services
Meeting Documents
Miscellaneous
Essential Reading
Magazine/Newspaper Articles/Letters
Adverts and Sales Brochures
The Mighty Garage Videos
Bikes For Sale (Spares Company)
Log in
Register
What's new
New posts
Menu
Log in
Register
Install the app
Install
Home
Forums
Forums: Public Access
Tech. Advice: Series 'B' / 'C' 500cc/1000cc Bikes
Timing of electronic ignition
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="Pete Appleton" data-source="post: 3183" data-attributes="member: 145"><p><strong>Timing</strong></p><p></p><p>You can get a pretty good idea of the timing by removing the advance/retard cover from the timing case, finding TDC through the plug hole with a screwdriver and then scribing a mark on a fibre gear tooth that lines up with a corresponding mark on the inside of the timing cover.</p><p></p><p>To work out the advance you need to divide 720 degrees by the number of teeth on the fibre gear (720 because it turns at half engine speed). This tells you how many degrees advance per gear tooth you are getting. This method is a bit rough and ready but seems quite accurate.</p><p></p><p>It is fashionable to keep retarding the ignition to allow for unleaded petrol e.t.c. If you look at the octane rating of the 'pool petrol' that the bike was using when new you could think that unleaded, with its higher octane rating and no need for compression plates, will need even more advance. Most of the 'pinking' problems occur when the Boyer unit (and to an extent the old ATD) advances to full advance too early. I run my Comet & Rapide at 8:1 and 40 degrees of advance at 3000 Rpm with a digital ignition system. I get no 'pinking' and no signs of melted spark plugs or pistons.</p><p></p><p>It is worth checking, with the strobe, when the advance takes place. If you are at full advance by 2000 RPM then 35 ish degrees advance is the best that you should use. If the timing curve keeps going beyond 2500 RPM then you should be able to give it a few degrees more.</p><p></p><p>Sorry to go on a bit but this is a pet project of mine</p><p></p><p>Pete</p></blockquote><p></p>
[QUOTE="Pete Appleton, post: 3183, member: 145"] [b]Timing[/b] You can get a pretty good idea of the timing by removing the advance/retard cover from the timing case, finding TDC through the plug hole with a screwdriver and then scribing a mark on a fibre gear tooth that lines up with a corresponding mark on the inside of the timing cover. To work out the advance you need to divide 720 degrees by the number of teeth on the fibre gear (720 because it turns at half engine speed). This tells you how many degrees advance per gear tooth you are getting. This method is a bit rough and ready but seems quite accurate. It is fashionable to keep retarding the ignition to allow for unleaded petrol e.t.c. If you look at the octane rating of the 'pool petrol' that the bike was using when new you could think that unleaded, with its higher octane rating and no need for compression plates, will need even more advance. Most of the 'pinking' problems occur when the Boyer unit (and to an extent the old ATD) advances to full advance too early. I run my Comet & Rapide at 8:1 and 40 degrees of advance at 3000 Rpm with a digital ignition system. I get no 'pinking' and no signs of melted spark plugs or pistons. It is worth checking, with the strobe, when the advance takes place. If you are at full advance by 2000 RPM then 35 ish degrees advance is the best that you should use. If the timing curve keeps going beyond 2500 RPM then you should be able to give it a few degrees more. Sorry to go on a bit but this is a pet project of mine Pete [/QUOTE]
Insert quotes…
Verification
The Series 'A' Rapide was known as the '********' Nightmare?
Post reply
Home
Forums
Forums: Public Access
Tech. Advice: Series 'B' / 'C' 500cc/1000cc Bikes
Timing of electronic ignition
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
Accept
Learn more…
Top