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Stag trip mileage, request for info



Hi Tim

Glad to hear you had a good trip, and car went very well (despite abysmal
fule consumption).

DRIVE SHAFTS
As Glenn says, Moly grease on the drive shaft splines, then renew every 2-3
years for perfect handling and absence of irritating 'klonk'.

FUELING
Your exhaust (and low running temp) indicate very rich mix.  Tailpipe
indication should be light brown veering to grey if you manage to use a
very light throttle (not been known in this house!).

Very first thing to do, is to make absolutely sure your choke cable is not
holding one/both cold starter box levers partially open - even
intermittently.

Note that both carbs feed into a common manifold chamber, so looking at
individual spark plugs to guess which carb is giving the problems, is
really a waste of time.  For this reason, a Gunsons Colortune does not work
well on the Stag unless you make identical alterations to both carbs at the
same time.

Before you re-tune the carbs, fix the dashpot problem.  There is a tiny
rubber 'O' ring at the bottom of the damper assembly which should stop the
oil running out of the dashpot, down the needle and into the engine.  This
has Triumph part number 512317.  Also avaialblefrom carburrettor
specialists, try www.burlen.co.uk

Then re-tune the carbs to the datum point, off the engine.  
1.  Start by making absolutely sure your float heights are both spot-on.  
2.  Then set the needles manually to exactly the same setting, 
      (shoulder flush to bottom of air valve)
3.  and butterfly gaps using a 0.0015" feeler guage.  
4.  Check sealing of the adaptor housing to manifold, especially look 
     for the stud pulling out of the manifold, creating a false ledge 
     which stops the adaptor housing bedding down properly on the
     manifold
5.  Check all breather hoses are clear of obstructions and fit well

Then refit to engine without connecting carbs to each other or to
accelerator linkage (you may need to connect choke cables to enable a
startup).   When fitting adaptor housing, always fit an annealed copper or
aluminium sealing washer under central nut as this is a source of
mixture-upsetting air leaks which stop the carbs being properly tuned.

Set final tune and idling without connecting linkages, making VERY sure you
adjust both carbs identically.

Then refit linkages afterwards and re-check air flows etc., adjusting
linkages to suit.  If you get it right the tuning will last for many years,
unlike SU's which need human intervention all the b..... time.

Mike Wattam
Triumph Stag Register



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