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post #1 of 3 (permalink) Old 12-07-2012, 04:04 PM Thread Starter
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Thruxton master cylinder piston bore


I have searched quite a bit with no definitive answer to my question. My question is, what is the piston bore on a stock Triumph Thruxton carbie and/or EFI?

Thank you for your help!

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post #2 of 3 (permalink) Old 12-07-2012, 05:40 PM
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My carb one has an 11 cast on the side of it. Educated guess would put it as a 11mm bore.

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post #3 of 3 (permalink) Old 12-07-2012, 06:02 PM
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Yes, they are 11mm bore for both carbed and EFI Thruxtons. In fact all Thruxtons, Bonnevilles, T100s and Scramblers use the same piston and seal spares kit (part # T2020087) whether they have the one-piece cast m/cyl and reservoir or the separate reservoir "pee pot". I.e. they're all 11mm.


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