Honda-SOHC
SOHC.co.uk Forums => Other Bikes => Topic started by: florence on September 03, 2017, 04:56:55 PM
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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?
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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.
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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
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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.
[attachimg=1]
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thanks Ash, brilliant.
I think I might just go for it. I can always swap back if it doesn't work well.
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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.
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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
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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 !!
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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
(https://i.ebayimg.com/images/g/ekwAAOSwMmBVkvcj/s-l500.jpg)