Triumph Repair: 1974 Spitfire Thermostatic valve hookup, vacuum switch, vacuum lines

Question
Hi Jim, welcome back. I have a late model 1974 Spitfire with the 1493cc engine,a supposed 150CD4 Stromberg carb,and a thermostatic vacuum valve. The Victoria catalog and the original service manual show one of the three vacuum lines from this valve going to the forward [no. 3] vapor trap then to the upper rear area of the carb where it terminates in an elbow marked "9" [ in the illustrations]. My carb has no connection for this line. Also, which of the 4 connectors on vacuum switch is not used? Bob

Answer
Bob,

How long have you had the car?  

There should be a fitting on the top of the carb near the manifold flange for connecting the fitting.  If there isn't then it sounds like someone swapped in an different year carb.

I don't have my manual in front of me but I want to say that it's the rear most fitting on the vacuum switch that doesn't get connected.  

Cheers,

Jim