Triumph Repair: loss of power, Triumph, Spitfire

Question
I have a 1974 Spitfire.  Just getting it to the point to drive on the street after sitting for several years.  Starts great, I drive about 1 to 1 1/2 miles and lose power.  It is like I have lost fuel.  I can put in the clutch and rev the engine but as soon as I put a load on it, it once again tries to die.  It has a petronix ignition and an electric fuel pump.  I have replaced the fuel filter, unhooked the fuel pump checked to be sure that fuel is being pushed through (strong stream).  I can turn off the ignition, sit for 2 to 3 minutes and start back up and it runs abut 1/4 mile OK before once again losing power.  At that point it can not pull the weight of the car on flat land much less a slight incline.

Answer
Shields,

Several possibilities.  

Fuel passages blocked in the carb or the float/needle sticking.   You're getting fuel up to the carb, that's no guarantee that it's getting into the engine.  Is the fuel pump wired into the ignition circuit?  Or on a separate feed/switch?

Another possibility is the mechanical advance weights are getting stuck in the full advance position.  They're spring loaded so they'll tend to pull back in when the car sits for a while.  They tend to get gummed up with oil/fumes from the engine working their way up along the distributor shaft.

You might also verify the timing settings.


Cheers,

Jim