[TR] Another Crazy Question: Beware, chestnut related

Randall tr3driver at ca.rr.com
Thu Jun 2 17:04:14 MDT 2011


> Haven't researched archives, so don't feel obligated to respond.  I
> seem to remember hearing a couple of different recommendations on how
> much to set the advance on a TR3A engine.  ISTR one was 4 degrees,
> another lister thought 8 degrees.  Engine is at I think 4 right now,
> but running as if it lacks the pep I'm used to.
> 
> Thoughts?

My suggestion would be to first confirm that both the centrifugal advance
and vacuum advance are doing at least something.  If either one has quit
working, it can make the engine feel sluggish without actually running
poorly.  You'll need a timing light to confirm the centrifugal advance :
Watch the timing mark while you slowly rev the engine up, observe that it
moves gradually to the right with increasing rpm, without jumping around all
over the place.  

For the vacuum advance, you'll also need a MityVac or similar (HF sells a
cheap unit that seems to actually be better quality than MityVac).
Disconnect the vacuum line from the distributor and hook your vacuum source
in its place.  Now watch the mark as you apply vacuum.  If it moves at all,
the unit is probably working OK.  Then you can just do a quick feel to
confirm the line isn't broken and dangling under the front carb.

Then set the initial advance using the "road test" method : Advance by 2
degree steps until you can just barely make the engine knock deliberately
(by lugging it in 4th gear with it warmed up thoroughly), and then back off
by 2 degrees.

-- Randall 



More information about the Triumphs mailing list