ET: Engine (Twin) Mikuni carbs

Gene Nehring

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I agree with Robert. I run a high quality fuel line that Michael Vane-hunt recommended to me and I replace it every now and then. Never had my carbs loose or come off.

Running a VM 34 that Robert helped me tune on my comet. Now has 8000 miles SMOH.
 

vibrac

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the hose is blue (other colors are available)
1597911648752.png

But for a guy with red handlebar rubbers that's not a problem ;)
 

erik

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The two Valve BMW s had a rubber between the cylinder head and the Bing carbs .Good Quality Rubbers!Erik
 

Les Thomson

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Just finished a mock up of front carb manifold. Using 40mm silicone radiator hose 30mm long. No gap between carb & manifold & carb will have a support bracket to stabilize.
 

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Chris Launders

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Have you got vacuum take off's in there, if not now would be a good time to do them, really helpful setting up your tickover and balancing
 

BigEd

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Just finished a mock up of front carb manifold. Using 40mm silicone radiator hose 30mm long. No gap between carb & manifold & carb will have a support bracket to stabilize.
On my Rapide I have 28mm VM28 Mikuni carbs mounted in the same way as yours, no additional support other than the radiator hose and hose clips and no problems.
Your carbs are larger so maybe a bit of extra support might be needed.
When my brother and I where vintage racing we had a longer piece of radiator hose mounted inlet tract on our Sunbeam single. We just used a stout rubber band (inner tube) from a frame tube and looped around the carb end to stop any drooping of the tract while still giving isolation from vibration. BSA Gold Stars used a metal bracket with a rubber insert to hang the big Amal remote mounted float bowl to prevent frothing. Probably you will not get frothing on a Vincent twin engine.
 

Les Thomson

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Pity the angle of both carbs are not the same. Maybe i'm overthinking it ???
Amal carbs were the same angle. Making up new cables & running in a day or so. Fingers crossed
 

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Chris Launders

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I have VM 34s on my Norvin with Amal rubbers and no other support, never had a problem in over 20 years although it doesn't get a lot of use I must admit.

I use one of these for balancing, picked one up 2nd hand but unused off ebay for a few quid, I have small boss's with 6mm internal thread, normally blanked off with 6 mm button Allen studs/fibre washers

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BigEd

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I have VM 34s on my Norvin with Amal rubbers and no other support, never had a problem in over 20 years although it doesn't get a lot of use I must admit.
I use one of these for balancing, picked one up 2nd hand but unused off ebay for a few quid, I have small boss's with 6mm internal thread, normally blanked off with 6 mm button Allen studs/fibre washers
The Carbtune is an excellent bit of kit and a lot more durable than the mercury gauges I used previously. The glass tubes were a bit delicate.
 
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