Author Topic: Triumph 3TA mystery!  (Read 159 times)

Offline Frankie J

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Triumph 3TA mystery!
« on: November 01, 2020, 02:10:12 PM »
I have a Triumph 350cc 3TA engine, 1961, and have found a 1/4 BSF threaded hole in each of the rocker boxes and I cannot fathom out what they are for. The wall thickness is only about 1/8 ins.

Has anyone got an Idea what they may be for?

Offline mini-me

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Re: Triumph 3TA mystery!
« Reply #1 on: November 01, 2020, 03:37:19 PM »
where is your 'ole and how many? sound to me as if the lower studs are awol

as here.https://www.vintage-motorcycle.com/en/parts/triumph-used/rocker-box-usedtriumph3ta5tat100at21-1

it'll be whit thread not BSf  unless its been bodged, likely.

Offline TGR90B

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Re: Triumph 3TA mystery!
« Reply #2 on: November 01, 2020, 05:45:25 PM »
Possibly someone tried to fix some sort of vent to each one. They do tend to be leaky if pressure builds up due to worn valve guides etc.
Getting grumpy, but not as grumpy as mini-me.