72 750 Combat Commando

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I have what appears to be a complete but very rough 72 750 Combat Commando Roadster.
The Frame and Engine number are 201714.
Norton Twin Restoration by Roy Bacon shows that these number show it as a Combat engine.

I would like to restore it but I am concerned if it is worth it due to this engine.
Can they be rebuilt and be reliable.
At this time the engine does turn and one of the cylinders has low compression.
I do not want to put money into something that is going to come apart.
Its use will be to pleasure ride it on occassion.

Thanks for you help.
 

grandpaul

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They can be made only as reliable as the parts that go in, the workmanship, and the 40 year old crankcases & core components.

Which is to say, thay can be made RELATIVELY more reliable than they were years ago, but the rider must excercise caution & restraint regarding over-revving and over-stressing.
 
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I live in North Florida, do you know of anyone who does reliable work on these engines?
My intent is to have the engine, carbs and tranny work if needed to be by a reliable source.
Most likely I would have this person inspect these items, and maybe the whole bike at first to get their opinon on how doable this project would be. Thanks
 

L.A.B.

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Most imprtantly, make sure it's fitted with the FAG type main bearings!
 
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Norton Twin Restoration by Roy Bacon shows that these number show it as a Combat engine.

Could be a Combat, the engine number alone cannot make it a combat, normal and combat engines were built using the same sequence of numbers. To have a Combat you need an engine built within the start and finish numbers for combat production plus the following.

Cylinder head stamped with a large C

Closer than normal gap between the top barrel fin and the bottom head fin. (caused by the 60 thou the factory skimmed off the head)

32 mm carbs feeding 32mm manifolds

2S cam

Front disc brake

As well as the FAG bearings LAB mentions you need the following mods

Shorten the pushrods by 60 thou (the factory forgot :roll: )

Modify the oil scavange as per this post combat-t4890.html
 

grandpaul

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Yes, the "Superblend" bearings, removal of the oil blocking lip at the rear of the sump, and modification of oil pump pickup orifices are all very important.
 
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Welcome to the forum and welcome to Norton ownership. My 1st. 72 combat was brand new and I rode it HARD! I was surprised to discover it it came with superblend main bearings so maybe I was lucky. I currently have 2 - 72 combats that I'm just beginning to resurrect after decades of sitting but there is no doubt in my mind they'll be contendas. I certainly don't consider a 72 Combat Norton to be a lemon.
As well as the afore mentioned FAG superblend bearings the crankcase modification is a good one:http://www.oldbritts.com/ob_start.html Most other performance mods have already been done on the combat. An electronic ignition is a must though.

michida said:
I live in North Florida, do you know of anyone who does reliable work on these engines?
My intent is to have the engine, carbs and tranny work if needed to be by a reliable source.
Most likely I would have this person inspect these items, and maybe the whole bike at first to get their opinon on how doable this project would be. Thanks

How far is that from Texas? Grandpaul (Born Again Bikes) who responded below does this work.
 
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kommando said:
Shorten the pushrods by 60 thou (the factory forgot :roll: )

Shorten the rods? I haven't heard of this, why is this recommended? (I've been asleep for over 20 years:)
 

grandpaul

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Shorten the PUSHRODS, not the connecting rods...

It restores the proper rocker arm geometry for the lowered head.
 
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My thought would be that running a compression ratio suited to today's gas, a cam more suited to torque, proper bearings and a good pistons, a combat could be more reliable than a standard when they left the factory.
Rather than shorten the pushrods I'd put a base spacer in or a thicker head gasket to get closer to nine to one. Fuel isn't likly to get better, as George Gobel said, "Things will get worse before they get better."
There are a lot of bits out there today that are better than we had when these were new. The ignitions for one are tremendously improved.
 
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I have a 72 Combat and I rides it hard.

You have to cange the main bearings and the required uppgrades and the engine is bullet proof, and its the most powerfull Commando.

JR
 
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