i am new to this site and i need some input, i have a 65 lark with the 355/4 brl, it runs fine but surges at higher speeds (65-75) cant figure it out, timing or carb?? help
It is either very lean, or you have too much timing at cruise. Check for a vacuum leak. Put a vacuum gauge on it. Fully warm, in Park, it should pull 20" of vacuum. If it is low, look for a damaged vacuum hose. Spray some carburetor cleaner around the base of the carburetor. Put a timing light on it and see where the timing is at higher engine speeds.
Thanks, i will give that a try, ive replaced all the vac hoses and tightened everything up, currently have the timing set at 10 degrees BTC, the manual calls for 2 1/2 BTC but it seems to run a little better at 10, maybe thats too much, thanks again!
When you increase the initial timing, you add to the total timing. Disconnect and plug the vacuum advance. Then take it for a ride and see if the surging disappears. If you have too much timing at a cruise, it will surge. Disconnecting the vacuum advance will drop out some timing. http://www.v8buick.com/showthread.php?63475-Power-Timing-your-Buick-V8
