| Also known as | 74-13394 |
| Listed in parts books | Not catalogued by year yet |
PISTONS NORTON850.040 JCC
A .040 oversize piston set for the Norton 850 twin, also referenced as 74-13394.
This is a piston set for the Norton 850 twin, listed at the .040 oversize for a rebore. It carries the alternate reference number 74-13394 alongside its current listing number, so if your parts book or an old invoice shows that older number, it's the same physical piston.
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Our catalog record on this one is brief - we don't have more detail on it beyond the description and the oversize designation. Norton is not a Triumph model, so if you came here cross-shopping Triumph twins, this piston set belongs on the Norton side of the shop, not the Triumph side.
Because it's an oversize (.040), it's meant to go with a cylinder that has already been bored out to match - it is not a standard-bore replacement. Call the shop and we'll confirm fitment and bore spec before you order.
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