Commando head and barrels unit

A

Andy M.

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Jan 31, 2025

Messages

1

• Jun 11, 2025

• #1

Hi all. Newbie to Nortons. Can the head and barrels be removed as a unit ? I have a supposedly rebuilt engine with fresh gaskets, but I was thinking of separating at base to check rings etc. It is out of the motorcycle at this time. Thanks.

 

L.A.B.

Moderator

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Nov 20, 2004

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21,090

• Jun 11, 2025

• #2

If it's a 750 then apparently you can lift the head and barrels as one unit if the engine is out of the frame.

 

kommando

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May 7, 2005

Messages

7,607

• Jun 11, 2025

• #3

A borescope picture of the bores, compression and leakdown test would tell you more with less pain.

 

baz

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May 26, 2010

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8,531

• Jun 11, 2025

• #4

Yes you can lift it off as one unit if as lab says it's a 750
But don't forget the cam followers will move down a touch and probably drop out of all 4 rocker arms
Plus you'll have the added weight to manage when refitting the top end
I'd just remove the head if it were mine

 

t ingermanson

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Oct 17, 2018

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677

• Jun 11, 2025

• #5

Refitting the pushrods on reassembly is a swearing man's game, while wrestling only the head. You'd have to invent dirtier words to refit the barrels and head together.

 

marshg246

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• Jun 11, 2025

• #6

Andy M. said:

Hi all. Newbie to Nortons. Can the head and barrels be removed as a unit ? I have a supposedly rebuilt engine with fresh gaskets, but I was thinking of separating at base to check rings etc. It is out of the motorcycle at this time. Thanks.

Click to expand...

Can you: Yes, if out of the frame.
Should you: Absolutely not! If you're crazy enough to do it, you better be strong enough to hold 50 pounds with one hand while getting the rings in the bore with the other and then while still holding it with one hand getting the rockers mated with the pushrods. If you have an engine hoist you could suspend it from that and make it reasonable but still difficult.

 

Deckard

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Jun 18, 2009

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426

• Jun 11, 2025

• #7

Being a newbie, better have a workshop maintenance manual. Nortons are unique, even between models. Regardless of 750/ 850, pull the head first. Rotate the pistons down to see if you even have honing in the bores if that motor hasn't even been run yet. Other things to consider would be priming the oil system before starting.
Plenty of advice here about prepping a rebuilt engine.

 

Richard Tool

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Aug 3, 2019

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• Jun 11, 2025

• #8

As others have noted you may be able to remove the barrels with the head still on but reassembly is another matter. Take the head off . A shop manual and Mick Hemmings ‘ Norton Engine DVD are worth getting.