change-over valves

[blk914]

1972 450sl, can the 2 change-over valves on the emission control be bypassed?

[230/8]

Should only be one emission system change over valve located on the vacuum line to the distributor. This valve allows vacuum to activate the spark retard function in the distributor. If you bypass the valve you will retard the spark all the time...not so good. Let me know if I have misunderstood your question because there are two other change over valves, for the ventilation system, but these are obviously not related to the emission system.

[blk914]

Thanks for the reply, that is what I needed to know.