1974 450SL, Dark_Blue/Parchment
Would this be advisable for a 74 as well?The 5 degree ATDC is an attempt to reduce emissions during idle. It is not neccessary to set the timing that way. In fact it is turned off whenever a/c is on or if coolant is over 100C.
Your car will run better if you set timing at 5 to 8 BTDC with the vacuum line to distributor disconnected and plugged. Reconnect vac after setting. At idle, you will now be at tdc - 5 BTDC Timing should then advance to about 27 BTDC when you rev to 3000rpm. If it doesn't, then there is a problem with centrifugal advance (internal weights)