Author Topic: 1972 CB350K Carbs  (Read 391 times)

Offline florence

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1972 CB350K Carbs
« on: September 03, 2017, 04:56:55 PM »
I tried to ask this question on Hondatwins but had no reply.  Has anyone here fitted 32mm MK1 Amal Concentrics to a CB250/350k or similar?

My original carbs need a complete overhaul and being CV type have always been a bit flakey, but I have a really good pair of Amals which will bolt straight on.  The carbs came with some home made manifolds, which makes me wonder if they came off a CB racer?

Online AshimotoK0

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Re: 1972 CB350K Carbs
« Reply #1 on: September 03, 2017, 05:52:11 PM »
I do remember back in the day people used to fit Amal carbs to CB250/350K but not sure if that  was because the early bike's carb  diaphragms split and the Honda replacements were mega expensive and no aftermarket fixes like you get today. I agree you often get zero response to a question on HondaTwins and you know there must be someone on there who has an answer. You could try someone like Tony Hales who used to do 350K race bikes ...I have his and Suzi's number somewhere if you need it. Meanwhile, I'll  ask around for you.
« Last Edit: September 04, 2017, 08:34:22 AM by AshimotoK0 »
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

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Re: 1972 CB350K Carbs
« Reply #2 on: September 03, 2017, 06:48:00 PM »
Seems there's a lot on using them on CB72/77's

hhttp://amalcarb.co.uk/downloadfiles/amal/amal_tuning_guide.pdf

ttp://www.honda305.com/forums/steadfast-amal-626-alternative-pwk-26-mm-carburetors-set-up-t7636073.html?highlight=amal&fref=gc&dti=745275825545348

You could ask the guy who posted this too:

http://www.hondatwins.net/forums/49-fuel-supply-carburation/36202-amal-mk2-concentric-carbs.html
« Last Edit: September 03, 2017, 06:51:20 PM by AshimotoK0 »
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

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Re: 1972 CB350K Carbs
« Reply #3 on: September 03, 2017, 11:50:48 PM »
I seem to think that Read-Titan of Leytonstone used to fit Amal carbs to their race kitted CB250's with their 325cc Hepolite conversions and their own camshaft   (CB350 not available in UK until 1972 'ish) ... I think Jock Kerr worked for them too at one time so hope to God he had nothing to do with it  :D

Here is (I think) one of their CB77 conversions with Amal carbs on it.

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« Last Edit: September 04, 2017, 12:19:06 AM by AshimotoK0 »
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline florence

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Re: 1972 CB350K Carbs
« Reply #4 on: September 04, 2017, 07:51:05 AM »
thanks Ash, brilliant.

I think I might just go for it.  I can always swap back if it doesn't work well.

Offline Tomb

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Re: 1972 CB350K Carbs
« Reply #5 on: September 04, 2017, 10:39:25 AM »
I use CB750 carbs on my bored out CB77/72, they're about 31mm I think so 32 Amals will work, you will have to put a lot bigger main jets in to counter the slower air flow rate.
Tom
'73 CB550 with CB500 engine café racer
'62 CB77 Sprinter
'70 CD175
'78 CB550 with sidecar
'80 Z50R
And a load of old Yamaha 1100's

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Re: 1972 CB350K Carbs
« Reply #6 on: September 04, 2017, 11:28:00 AM »
I use CB750 carbs on my bored out CB77/72, they're about 31mm I think so 32 Amals will work, you will have to put a lot bigger main jets in to counter the slower air flow rate.

I think Hales Honda used those too ..trouble is they were a pair from a CB750K0 == ££££ ... he was a selling a pair a while back cheap on eBay  and I put UK Pete onto them to try and reunite them with a 750K0
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline Johnwebley

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Re: 1972 CB350K Carbs
« Reply #7 on: September 04, 2017, 12:04:45 PM »
I seem to think that Read-Titan of Leytonstone used to fit Amal carbs to their race kitted CB250's with their 325cc Hepolite conversions and their own camshaft   (CB350 not available in UK until 1972 'ish) ... I think Jock Kerr worked for them too at one time so hope to God he had nothing to do with it  :D

Here is (I think) one of their CB77 conversions with Amal carbs on it.

(Attachment Link)


 thanks Ash,great picture,that is a classic cafe racer !!
lifelong motorcycle rider,and fan

Offline Tomb

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Re: 1972 CB350K Carbs
« Reply #8 on: September 04, 2017, 12:05:24 PM »
Having the screw on tops made them ideal for converting to cable operated, only problem was no tickover, for racing this was never an issue but would be on a road bike. Amals wouldn't have that issue, I only mentioned using the CB750 carbs as a similar size.

I've looked around at replacement carbs for a few of my old bikes, my daughter has a Huoniao HN125 with a copy of a CG125 engine, its well made (never thought I'd hear myself saying that about a Chinese bike) and the carburation is good and a Chinese copy carb, it made me think about buying some for other bikes.
http://www.ebay.co.uk/itm/26mm-PZ26-CHINESE-IMPORT-PIT-DIRT-BIKE-CARB-CARBURETTOR-110cc-125cc-PITBIKE-/141778401746?hash=item2102a6b9d2:g:ekwAAOSwMmBVkvcj

Tom
'73 CB550 with CB500 engine café racer
'62 CB77 Sprinter
'70 CD175
'78 CB550 with sidecar
'80 Z50R
And a load of old Yamaha 1100's

 

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