| Also known as | 50-0653 |
| Listed in parts books | Not catalogued by year yet |
EXHAUST VALVE GUIDE NORTON 850 +.002 KWPM
Oversize (+.002) exhaust valve guide for the Norton 850 twin, also listed as 50-0653.
This is an exhaust valve guide for the Norton 850, oversized at +.002 over standard to allow for a tight fit on rebuilds where the original guide bore has worn. It's a Norton part, not a Triumph one, despite what our system might file it under — worth flagging since we're primarily a Triumph counter and don't carry deep stock on Norton internals.
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The guide is the fixed bore in the head that the exhaust valve stem rides in and slides through as it opens and closes. Going oversize by .002 in. means the machinist fitting it needs to ream or bore the head to match, so this isn't a drop-in part — plan on a machine shop step as part of the install.
We show this part under the number 064125/002, with the older-style number 50-0653 also on file for the same physical piece. If you're working from an older Norton parts book and see 50-0653 listed, that's this same guide. Give us a call if you want to confirm what you've got before ordering.
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