New guy with carb model question

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msh5337

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New owner of a 73 roadster here. I've been on the forum for a bit now lurking in the shadows, but have finally come across something I can't find. I'm in the middle of tearing the bike apart to get the frame powder coated. I figure that while I'm at it I'll send the Amals off to get the resleeved (bike likes to die at stop signs) from Lund Machine Co. Well while I was boxing the carbs up I noticed that one is a 932/27, and the other is a 932/19. Is this okay, or are both carbs supposed to be the same model number?
 
msh5337 said:
Well while I was boxing the carbs up I noticed that one is a 932/27, and the other is a 932/19. Is this okay, or are both carbs supposed to be the same model number?
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Not exactly the same number.

1973 750 would be a 932/26 (RH) and 932/27 (LH).

932/19 (RH) is 1972, however, if the jets, slides, needles and clip positions all match then there's nothing to worry about (the only actual difference between 26/27 and 19/20 should be the main jet size).
 
Norton Newbie said:
I stumbled upon this list - presumably fairly recent from Amal - that lists many Mk1 Concentric carb and pair numbers:

Amal/ACK-PACK-Kit-Info.pdf
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Yes, it's an Amal list, 932/26 & 27 are "1973 750" (750 MkV) with 32mm inlet (RH5 & RH6) heads as there was no 1973 "Combat".
 
L.A.B. said:
Yes, it's an Amal list, 932/26 & 27 are "1973 750" (750 MkV) with 32mm inlet (RH5 & RH6) heads as there was no 1973 "Combat".
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Technically true - but in fact many US sold Combats are registered as 1973. As is mine.
 
tomspro said:
L.A.B. said:
Yes, it's an Amal list, 932/26 & 27 are "1973 750" (750 MkV) with 32mm inlet (RH5 & RH6) heads as there was no 1973 "Combat".
Click to expand...

Technically true - but in fact many US sold Combats are registered as 1973. As is mine.
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Certainly, it's just that the Amal list gives the impression there was an actual 1973 Combat model or that a '73 750 Commando fitted with 932/26 & 27 carbs is a Combat.
 
Awesome! Thanks guys, and thanks for the welcome. Everything else matches. Even the main jets at 230. That's just really strange to me. The bike it listed and is titled as a 1973, but the PO said he thought it was a "left over" 1972 model, post combat engine. So did the carbs come like that from the factory? Would Norton have used spare parts from the year before?
 
msh5337 said:
The bike it listed and is titled as a 1973, but the PO said he thought it was a "left over" 1972 model, post combat engine. So did the carbs come like that from the factory? Would Norton have used spare parts from the year before?
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Probably not.

Depends whether it is actually a late '72 post Combat or a '73 model, but we would need more detailed information such as (at least) the first three digits of the (hopefully matching) 6-digit engine and frame plate serial number (and date stamp), and if possible, the cylinder head marking (RH6? RH5?).
 
Okay, I should probably post this in another thread, but if you guys don't mind, the frame and engine number are both 230537. The head marking is RH5.
 
msh5337 said:
the frame and engine number are both 230537. The head marking is RH5
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Ok thanks.

230xxx is 1973, although it could have been built in late '72, but as it has a '230' number I doubt it would have left the factory with 'odd' carbs.
 
So it's not a combat then. Okay one last question. After reading up on the new Amal premiers I think I might just bite the bullet and go for those. Would it be better to go with the 932 like I currently have? Or go with the 930 like the Amal list suggests for a 73? Thanks LAB I really appreciate it.
 
msh5337 said:
Would it be better to go with the 932 like I currently have? Or go with the 930 like the Amal list suggests for a 73?
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That list is a bit misleading!

Your post-Combat RH5 standard (or 'low') compression head and also the 'high' comp. RH6 head are 32mm inlet port size so the correct original carbs are 932.

The Amal reference to "930" for "1973 750" seems to be for the 30mm inlet port RH1 cylinder head option also available during 1973 although according to the '73 Norton parts book they were 930/63 & 64 not 82 & 83 as it says in the Amal list.
 
For manufacture time frame reference my 230615 headstock ID plate was stamped March 1973.
With RH5 head and 32 Amals.
 
Sleeving or new carbs, it's a toss up. If the innards are already new, get it sleeved by Lund's. You'll be quite happy with the way it idles. If all the innards need replacing, I'd go for new carbs.
 
Perfect! Thanks again LAB! Yeah Bob that helps. I'm not exactly sure what mine is dated as the idiot who powder coated it before me didn't remove the frame plate and only the serial number is legible. But I'm sure ours are pretty close. Yeah, I'm having a tough time deciding on the carbs for sure. Having them sleeved will save me a good 160 bucks, but I'm just not too sure about the innards. The bike ran really well before I pulled them (other than at idle), and they seem like they're in good shape. But then I'm not sure what ones in bad shape look like. Lol
 
msh5337 said:
I'm not exactly sure what mine is dated as the idiot who powder coated it before me didn't remove the frame plate and only the serial number is legible.
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Are the upper and lower yokes/triple trees marked 'ANG' on the underside by any chance?
 
msh5337 said:
Yep. They sure are.
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Thanks, that would suggest it has an '850' frame as other 230 series 750 models seem to have.
 
Well, if you sleeve them and they work, you're ahead. If not, you need new jets and all and the total will be about the same as if you bought new Premiers. It's a crap shoot, but in either case they will work fine. I did it backwards and replaced the innards first and then had them sleeved, after the Premier's came out. The sleeve job sure fixed the idle, I can take my hand off the grip now for the first time in 40 years, but it has to be warmed up.
 
That's interesting, and good to know. Might come in handy during this restoration.

Well, I went with the premiers. Ended up finding a really good deal on a pair, and I figure I can maybe sell the old ones and make a little money back. Yeah, I'm excited about not having to death grip the throttle in fear of it stalling. Can't tell you how many people I've pissed off rolling up to a stop sign, having it die, then fumbling around trying to get it kicked back over. Lol
 
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