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[TR] Recalcitrant TR3B Engine

Subject: [TR] Recalcitrant TR3B Engine
From: TR3driver at ca.rr.com (Randall)
Date: Sun, 4 Mar 2012 10:40:10 -0800
References: <4F534D18020000EF0000C7B7@smtp.mainet.com>
>   a. Timing verified as correct with visual check of rotor 
> position at #1 cylinder TDC.

Was that with #1 ready to fire?  Each piston comes to TDC twice per cycle;
the spark has to hit the right one (which is when both valves are closed).

>  d. Carb needle settings - tried 10 to 13 flats

Carb needle setting should be irrelevant at this point; you should be using
the choke which means the jets will be pulled down and not resting against
the adjustment at all.

>   f. Engine fires strongly when starter fluid sprayed into carbs which
> indicates that the ignition system is working properly

Can you keep it running on the starter fluid?  Or does it just fire once or
twice and not actually start?

If the former, then it is clearly not getting enough fuel.  Try giving it
more choke.  If that doesn't work, drain and replace the fuel.  Modern fuel
spoils quickly when stored in a vented tank (like the TR3 tank).

If the latter, I would suspect the timing is 180 out.  BTDT

>   b. Verified valve gaps set to .012
>   e. Point gap set to  .013.

Is there some reason you aren't using the factory values (.010 and .015
respectively)?  I doubt that is the problem, I'm just curious.

Another possibility based on your report would be a largish intake vacuum
leak, like maybe the intake manifold is not correctly seated against the
head.  It can sometimes catch on the alignment pins and stick out at the
bottom where it is hard to see.  Or if the head has been machined to
increase compression, the manifold may catch on the edge of the block and
cause the same problem.  I have also seen problems caused by tightening the
nuts on the connection between intake and exhaust, before having both
manifolds clamped to the head.  (I leave those nuts off on my TR.)

-- Randall  

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