Triumph Repair: Fuel problem, triumph spitfire 1500, guestion

Question
David - we are recent owners of a 1978 Triumph Spitfire 1500.  Yesterday the car began to lose speed power.  It is a 4 speed manual engine.  It idles fine.  However, take off power and gaining speed to shift is extremely slow.  We have replaced the fuel filter and have had no improvement.  It acts like it is starved for gas.  The fuel pump is manual and we don't think it is the problem (a manual pump either is working or not working, right?).  The engine did try and keep running when we turned it off this last time.  Could we have a carburetor problem and if so, how do we adjust the carburetor.  We have no maunual.  Thank you.

Answer
Hi, sorry for the delay. my triumph work was mostly earlier years and by 1978 the carb was emissiond and might not be adjustable. a fuel pump can go bad and still work some.it has a rubber diaphram that can split and if it's bad enough will pour gas into the oil. did it run ok when you got and if so how long? you might take the fuel bowl off of the bottom and look for trash in it. also the timing sounds like it might be advanced but as i was trying to answer a guestion for some one else discoverd the wrong distributor was in the engine. Dave