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
ATD Advance Timing Curve?
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="Martyn Goodwin" data-source="post: 51230" data-attributes="member: 2433"><p>Hi Greg,</p><p></p><p>Your observations are spot on. I am (now) running a CP piston reputed to be 7.5:1 and using 98 octane (RON) fuel. I have my Mk1 Amal carb jetted with a 105 needle jet (106 was way too rich at partial throttle openings) and a 220 main (a 210 was used earlier). I am using a Mk1 cam. Biggest difference is the ignition settings - earlier I had 36 BTDC full advance with 4 BTDC when retarded. I also discovered that the pivot pins in the ATD were loose so its very possible that I was actually running a full advance a tad greater then the static set of 36. By repairing and tweaking the ATD (with some kind welding assistance from Ken Phelps) I an now running 32 BTDC advanced and 4 BTDC retarded - and I am using the original Lucas Magneto, rebuilt almost 14,000 miles back by Peter Scott.</p><p></p><p>Of passing interest - over the last few days I fitted a Pazon system - you beaut modern electronics - that provided 28 BTDC advanced and 2 BTDC retarded; my impression was an overall reduction in performance (of the bike) compared to my magneto setup. I then "adjusted" the Pazon to give 32 BTDC advanced and 6 BTDC retarded but was still not fully happy with overall performance, when "seat of the pants" compared to the earlier magneto setup.</p><p></p><p>I refitted the original Lucas magneto earlier today and then did a quick 60 miles test run just to confirm my conclusions on performance. The magneto will be staying in the bike!</p><p></p><p>I know what you are saying about the exhaust note. One of my favorite "tricks" is to take my Comet through the Mullum Mullum and Melba road tunnels at a moderate speed then open up the throttle and revel in the booming noise echoing around - seems to wake up any car drivers in the immediate area! As to open road speeds - I get a small amount of vibration around 92 to 95 kph but it smooths out if I go a bit faster. Happy all day running speed seems to be around 105 kph (about 65 mph).</p><p></p><p>Martyn</p></blockquote><p></p>
[QUOTE="Martyn Goodwin, post: 51230, member: 2433"] Hi Greg, Your observations are spot on. I am (now) running a CP piston reputed to be 7.5:1 and using 98 octane (RON) fuel. I have my Mk1 Amal carb jetted with a 105 needle jet (106 was way too rich at partial throttle openings) and a 220 main (a 210 was used earlier). I am using a Mk1 cam. Biggest difference is the ignition settings - earlier I had 36 BTDC full advance with 4 BTDC when retarded. I also discovered that the pivot pins in the ATD were loose so its very possible that I was actually running a full advance a tad greater then the static set of 36. By repairing and tweaking the ATD (with some kind welding assistance from Ken Phelps) I an now running 32 BTDC advanced and 4 BTDC retarded - and I am using the original Lucas Magneto, rebuilt almost 14,000 miles back by Peter Scott. Of passing interest - over the last few days I fitted a Pazon system - you beaut modern electronics - that provided 28 BTDC advanced and 2 BTDC retarded; my impression was an overall reduction in performance (of the bike) compared to my magneto setup. I then "adjusted" the Pazon to give 32 BTDC advanced and 6 BTDC retarded but was still not fully happy with overall performance, when "seat of the pants" compared to the earlier magneto setup. I refitted the original Lucas magneto earlier today and then did a quick 60 miles test run just to confirm my conclusions on performance. The magneto will be staying in the bike! I know what you are saying about the exhaust note. One of my favorite "tricks" is to take my Comet through the Mullum Mullum and Melba road tunnels at a moderate speed then open up the throttle and revel in the booming noise echoing around - seems to wake up any car drivers in the immediate area! As to open road speeds - I get a small amount of vibration around 92 to 95 kph but it smooths out if I go a bit faster. Happy all day running speed seems to be around 105 kph (about 65 mph). Martyn [/QUOTE]
Insert quotes…
Verification
What was Mr Vincent's Christian Name?
Post reply
Home
Forums
Forums: Public Access
Tech. Advice: Series 'B' / 'C' 500cc/1000cc Bikes
ATD Advance Timing Curve?
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