I recently installed a Weber down draught on the 79 Spit. The instructions
said cap off the vacuum line. Did it. And to resent the timing to about 13
degrees BTDC. I did do, but the fuel economy was down around the 23 mpg I
had been getting with Dellorto, not the 35+ as was the promise with the
Weber.
As I was getting no pinging, I advanced the timing even more. It is now
closer to 16 BTDC. I run 89 Octane and get no pinging. Am I still running a
risk of engine damage, blown head gasget, etc at 16 degrees. Fuel economy
has zoomed to mid 30's.
The dist is the original Lucas with the vac retard (now capped off). So the
only advance is the centrifugal advance. This adds about another 10-15
degrees of advance at the engine revs to about 2000 rpm.
Expert help needed.
Happy Motoring, and keep the shiny side up!!
Brian Neuschwander
1979 Spitfire
1965 Spitfire
1959 Sprite
1963 Consul Capri
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