Triumph Repair: spitfire 1500 engine, piston rings, head gasket

Question
i started up the engine after the winter,it was fine at first then it started misfiring i thought it was the head gasket so i changed that but it is still misfiring. i think i can smell fuel in the engine oil.is it a cracked piston or piston rings??

Answer
I would suggest first doing a compression test and/or a leak down test to answer whether the rings or pistons are bad.

Misfiring has many sources from electrical to fuel to compression, so you have to go through a process of elimination to determine the cause.  If the car ran OK in the fall, and you changed nothing, and had a misfire in the spring, I would start with verifying the ignition and  spark are OK, and then move to cleaning the carb.  See if you can identify which cylinder is misfiring.  I have done this by putting a timing light on each cylinder spark plug lead and seeing which one isn't flashing like the others