Tune-up Data

Triumph TR3a and 4


Sparkplugs: Champion L87YC or L87Y

Plug gap: .025


Valve Lash: .010 engine cold. Engines with aluminum rockershaft pedestals. Early engines are .010 intake and .012 exhaust.

Firing Order: 1-3-4-2


Point Gap: .015

Timing mark is a hole on the pulley on the front of the crankshaft. When that hole is lined up with the pointer on the timing chain cover, the engine is at TDC.

Static Ignition Timing: 4 degrees BTDC.

4 degrees measures about 3/16 on the periphery of the crankshaft pulley or one division on the vernier adjuster on the distributor advance.


Carburetor float height: 7/16"

Standard needle 4a: SM Standard needle 3a: FV