[TR] Rough running TR2

[Randall]

> What was
> discovered is very poor vacuum registered off the vacuum advance pipe,

With no load on the engine, there should be almost no vacuum at the advance
fitting.  The port is deliberately arranged so the throttle must be
partially open to expose it to manifold vacuum.

> with
> air filters removed the front piston lifting poorly when you try to
> increase revs

What happens when you try to lift and release the pistons with your finger
(engine off) ?  With the damper plunger installed, there should be a very
definite resistance to movement, but "oily" and smooth with no sign of grit
or dragging.  Then when you release the piston, it should fall quickly and
land with an audible 'click'.

If memory serves, the early TR2 carbs had small holes through the brass
plugs for the damper plungers, which served to vent the internal chamber.
Later carbs had this vent incorporated in the dome, and so no vent through
the plug.  It's important that there be some vent.

Also, the pistons are matched to the domes.  If they have gotten
inadvertently swapped, you may have one that moves too easily (too much
clearance to the dome) while the other drags (too little clearance).  Maybe
someone will have the link to the video of John Twist demonstrating how to
test for that.

You might try to look at the bottom edge of the manifold where it is bolted
to the head.  (I know, not an easy task!)  The cylinder block actually
sticks out beyond the surface of the head, and the manifold can sometimes
foul on the block, creating a huge air leak at that point.  But from your
description, I doubt an air leak is the problem.  Air leaks tend to be most
noticeable at idle (when air flow is lowest) and have relatively little
effect once the throttle is opened (because relatively more of the air goes
through the carbs).

What happens if you lift the pistons with the engine running?

Were the jets & needles replaced as part of the rebuild?  Are we sure they
are both the correct part?  The TR2 used .090" jets & needles, while the
TR3-4 used .100".  Some vendors may have forgotten this, or the parts may
have just been in the wrong bin.

-- Randall