Triumph Repair: 1979 Triumph Spitfire, triumph spitfire 1500, pertronix electronic ignition

Question
QUESTION: Hello
I am 16 years old and I recently bought a 1979 Triumph Spitfire 1500 and I do not know too much about restoring the engine.  I have two questions.
The fist question is about the ignition switch and key.  When I turn the key to turn over the engine the engine runs but when i let go of the key it turns off. I tested with it and noticed that the key turns itself to the off position instead of going just to the number two position, so when i would let go of the key it would flip back all the way to the off position.  I started it and then held it halfway between where it went to and where it would cause the starter to turn and it worked.  i took the plastic covering off around the steering column and switches and noticed that in fact i was holding it on the Number two position.  How is this fixed?
My second question is that when i get it running it idols very low and it sounds like it is skipping around and it bounces around and shakes pretty violently until it stops. When I give it gas it sounds pretty good and runs fairly smooth. How do i fix this?   Does it need to be timed or something?  
It has a Pertronix electronic ignition and i put new spark plugs in.
Thanks a lot
Mike

ANSWER: Michael,

1)  Ignition switch problem.   The ignition lock is supposed to stay in the "run" position until it's turned off.  When it starts just twisting back to "off" on it's own it's most likely that the mechanical switch portion is bad.  Best bet is to see if one is available new, or to find a used good one.


2)  Poor idle.   Do you know how old the gas is?   With the modern fuels, when they're more than a few months old they tend to go "off".   

If the gasoline is fresh then it's worth checking that the fuel mixture is set correctly.   



Cheers,

Jim

---------- FOLLOW-UP ----------

QUESTION: Thanks
It is new fuel. How do set the fuel mixture?
Thanks
Mike

Answer
Mike,

Assuming it's the stock carb setup, there's a special tool for moving the needle in the Stromberg.  Otherwise you run the risk of tearing the rubber diaphram in the carb.


Best bet is to track down the Robert Bentley manual for the car.   Worth it's price in avoiding skinned knuckles.


Cheers,

Jim