Author Topic: Monobloc replacement  (Read 1578 times)

Offline Nakhodka5

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Monobloc replacement
« on: 25.09. 2016 20:20 »
Hi,
I'd like to get my '57 A10 back on the road.  Since the mid eighties I've ridden modern(ish) bikes so I've become slightly spoilt on little things like handling, brakes, lights, starting, well, you name it really.

I can suffer all of these on the A10 apart from a couple.   The main one being the Amal Monobloc carburettor.  I'm sorry, I just can't be having to tickle the carb, and all that it entails every
time that I want to start it. 
Is there such a thing as an 'A10 carburettor replacement kit' which would bolt on without too much trouble and also has a throttle cable that attaches to the twist grip?
I don't really want an Amal concentric either.
While I'm asking, I suppose that I'd better include a request for any information about modern, sensibly designed petrol taps that will thread into a standard tank.

Basically I'd like to be able to apply the choke if necessary and kick it into life; no farting about with opening a petrol tap and covering a glove with petrol!

Thanks,
Steve
'57 A10
2001 Honda CG125
2000 Kawasaki ER5
2010 Focus
'87 BMW M535I

Online Klaus

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Re: Monobloc replacement
« Reply #1 on: 25.09. 2016 20:38 »
Hi Steve,

SRM offers a komplete Mikuni Carb kit for A10 alloy heads.

Have look at here:

http://shop.srmclassicbikes.com/product/mikuni-carb-kit-bsa-a10-650cc-alloy-head-30mm

cheers Klaus


If you think, everything is under control, you are not fast enought.

BSA DB34 Goldstar, BSA A10 Road Rocked, BSA A7 Shooting Star, BSA M33, BSA M24, Kawa W650

Online Triton Thrasher

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Re: Monobloc replacement
« Reply #2 on: 25.09. 2016 21:30 »
I have no sympathy for your reluctance to tickle the carburettor, but with the air slide closed and the throttle open, you may not need the tickler for cold starts.

adm edit, removed some 'non-tech' comments

Online trevinoz

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Re: Monobloc replacement
« Reply #3 on: 25.09. 2016 22:31 »
Now, now, TT. Not nice.

adm comment: post #2 edited.

Offline Rocket Racer

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Re: Monobloc replacement
« Reply #4 on: 26.09. 2016 05:46 »
Steve,
for your fuel taps as the taps simply need brass threads which are still available on a number of taps, you are spoilt for choice, my race bike and B33 run taps from the local swimming pool/spa shop and have the various brass thread adapters. My triple runs the period taps which are available still new and fine.

Carbs are a tricky one and personally I would avoid anything japanese as your just creating problems and devaluing the bike.
My B33 which runs a worn out pre monoblock, starts purely on the choke (no tickling) but my triple refuses to start on choke and must be heavily flooded. - I gave up and removed the chokes.
I must admit that both my road and race A10's both run TT carbs and love a wee tickle.

The mk 1.5 concentrics have a modified choke circuit and no tickler, can't say I've any experience with them. The pilot circuit is better I recall too.
Personally I'd stick to the original monoblock and take a teaspoon of concrete  ;).

I avoid riding modern bikes, much like comparing a vintage car to a modern, they just highlight all the "character" in a not good way.
A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
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beezermacc

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Re: Monobloc replacement
« Reply #5 on: 26.09. 2016 07:56 »
The Mikuni is a good option but a well-sorted monobloc should provide easy starting and smooth running so I can't see the point in spoiling the bike with a Japanese carb (and the Mikuni looks VERY Japanese). You can, of course, buy new monoblocs now from AMAL. The general consensus is that these carbs are pretty good and a lot cheaper than the Mikuni. I can't quite understand why holding the tickler button down for a couple of seconds is an issue. You don't actually need to flood the carb, just make sure there is fuel in it.

Offline muskrat

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Re: Monobloc replacement
« Reply #6 on: 26.09. 2016 09:06 »
I have a pair of these on my cafe. They were a bugga to get tuned right but once done they perform well.
http://www.lowbrowcustoms.com/jrc-30mm-carburetors-pwk-keihin-replace-amal-930-and-mikuni.html
Cheers
'51 A7 plunger, '57 A7SS racer now a A10CR, '78 XT500, '83 CB1100F, 88 HD FXST, 2000 CBR929RR ex Honda Australia Superbike .
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Online KiwiGF

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Re: Monobloc replacement
« Reply #7 on: 26.09. 2016 09:09 »
I thought mikuni carbs came from the good old U.S. Of A?  *dunno2* *conf2*
New Zealand

1956 A10 Golden Flash  (1st finished project)
1949 B31 rigid “400cc”  (2nd finished project)
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Offline ellis

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Re: Monobloc replacement
« Reply #8 on: 26.09. 2016 11:50 »
Just bought a new Amal 389/45 carb from Amal for my 1960 A10. £178. The bike now runs well and ticks over and also starts first kick with a 2 second tickle and no fuel spillage. A well worth investment and a great company to deal with. *smiley4* *smiley4*

Offline chaterlea25

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Re: Monobloc replacement
« Reply #9 on: 26.09. 2016 14:10 »
Hi All,
Not taking sides on AMAL vs others but I'm a mikuni fan

UK Mikuni prices are "off the wall"  *angry*
Of course the USA Mikuni dealers will not send to Europe ??
eBay offer Mikunis at great value but you need to be able to have the seller spec the carb for you
as usual jets and so on are costly

http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2060353.m570.l1313.TR4.TRC0.A0.H0.XMikuni+VM30.TRS0&_nkw=Mikuni+VM30&_sacat=0

The other way round the problem is to get someone in USA to buy the carb and post it privately to Europe

I think the 30mm will be too big for an iron headed A10 ?? 28mm would be good

http://www.ebay.co.uk/sch/i.html?_odkw=Mikuni+VM30&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR1.TRC0.A0.H0.XMikuni+VM28.TRS0&_nkw=Mikuni+VM28&_sacat=0

Of course you need to add the angles cable entry flange adaptor and air filter and and and ??
If you go Mikuni you can add a cable operated choke

2 cent opinion
John
1961 Super Rocket
1963 RGS (ongoing)

Offline rocker21

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Re: Monobloc replacement
« Reply #10 on: 27.09. 2016 13:56 »
try the JRC carb from brill bike parts, made in the USA and works well . www.brillbikeparts.co.uk
got one on my A7ss and it has made a big difference and a lot cheaper than a mikuni  (not sure how to spell that)
1960 A7SS, 1954 Ariel fieldmaster 500 twin, motoguzzi Monza 500, motoguzzi V7III special, Yamaha sr400 (2014)