I have recently bought a GT6 Mk3 (1971). It appears to be fitted with the age appropriate CDSE carbs and the 311749 early Mk3 inlet manifold but the engine has been replaced with a later engine, KE21904HE, and the crankcase breather valve is no longer fitted.
With ignition timing, tappets and plug gaps all set correctly, the engine runs with the front three cylinders far too rich, while the back three cylinders are running at the correct mixture. Can the mixture be made more lean on the front carburetter or is there something possibly wrong with the temperature compensator or throttle by-pass, please ? The Insulator and gaskets between carb and manifold have an internal slot , presumably part of the throttle by pass, which the gasket does not appear to fully seal from atmosphere, is this correct ?
I have no experience of Strombergs, would fitting an earlier CD set without emissions control be possible and make life easier, or even an SU conversion ?
If I have to have the carbs reconditioned, is there a recommended firm to contact ?
All suggestions gratefully received.