first post first nortons

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Ok First post .............hello . From Kansas city missouri way


Here is what I have ..
1973 commando minus the head paid $600.00 with title
1972 750 commando with engine complete made into a 70s chop . sluged tubes and mustang tank and a old chopper buttom tuck seat. this was a freebie from orginal owner .

What I bought was a 1973 750 with 932 carbs ( there was no cylinder or head assembly ) on it . The engine was a 73 model . What I have done is swap a complete 72 750 engine (I had it rebuilt ) into the 73 frame . The carbs on the 72 are 930s.
So why do I have both 930s and 932s .which ones to use?
Did they use 932s on the 1973 750 commando ?
And now the big question . will 750 atlas head work on a 750 commando ?
Of course there will be many more questions asked . like building my own iginition system using gm parts etc...

thanks in advace
Dr mac
 
The '72 Commando could be a non-Combat model which would have 930 carbs and a low compression head.
 
Check the diameter of the intake ports on your head. The carbs and intakes should be matched in diameter to the head, for best performance.

Welcome!
 
Did they use 932s on the 1973 750 commando ?
All '73 750's had 932's, both low and high compression models. For '72 low compression models used 930's while Combat engines got 932's

And now the big question . will 750 atlas head work on a 750 commando ?

Yes, but the four outermost bolt holes must be drilled from 5/16 to 3/8 to mate to the Commando barrels. And as Grand Paul points out be sure to match manifold bore to intake port and to carburetor. Also if memory serves me correctly, there is a difference in valve stem length and rockers from Atlas to Commando, so be sure not to mix and match valves and rockers. I'm sure someone will correct me if I am wrong on this. :wink:
 
hi dr, just to add a bit to what others have said, the oil feed and headsteady arrangements are different on the atlas heads
 
forgot to add im sure the rockers are the same but i think the valves and pushrods are slightly different
 
Greeting Dr Mac in Kansas city missouri way and welcome. Congrats on your excellent purchases!

You should add your location into your profile, it's quick and easy and often comes in handy for us all down the road.
 
I recall the mating surface is different on an Atlas head. I had to mill Atlas barrels flat to fit them on a Commando.
 
I recall the mating surface is different on an Atlas head. I had to mill Atlas barrels flat to fit them on a Commando.

Early Atlas barrels were spigotted. Later ones were not but still had 5/16 head bolts.
 
oh what the heck I'll just build a combat . Since I will need to rebuilt it anyways.
And it will go on a cafe . I'll go and build it combat and just have fun . Was a freebie anyways sort of .

I see acombat head on ebay now . I'll watch and see what it goes for . Also will need to do research on the combat and see what all will have to be worked on to have it hold up .
Did I say there will be lots of questions .?
So I'll have one 73 with a 72 engine. And one 72 built into a combat usiing the 73 engine. . .The 73 is nearing a start up in the next month or at least I'am hoping .
Guy I bought the 73 from had painted it orange . I think any other color will be a improvement.
Will post some pics this weekend.

Dr mac
 
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