Engine breathing

[Mike Wattam <101714.1343@domain.elided>]

Hi David

Your message:

"At the rear of the left hand rocker there is a pipe which runs for 9
inches
and terminates in a small 2inch cone "filter". When hot engine gases can be
seen coming from here"

This is definitely non-standard and it will upset the running of your car
(besides giving nasty oily engine smells inside the car).  The Stag is
intended to run with 'closed circuit breathing' which essentially means the
engine is supposed to burn off its own by-products.

The pipe from the rocker cover should have a short hose on it, then a tee
piece branching into two hoses, each going to adaptors on the carburettor
bodies - these are angled up at 45 degrees just below the diaphragm
chambers.

Relevant part numbers are;

short hose      154213
tee piece               154211
hose LH carb    216924
hose RH carb    216923

You will almost certainly find your mixture strength and tickover need
sorting out after this, and it should give you a much better low speed
throttle response.

Note that the hose id often not a good fit on the pipe on the rocker cover,
if so it is beneficial to use a worm drive clip to give an airtight joint.

Mike Wattam
Triumph Stag Register