2 Front Heads - Rear Manifold Question

[The VOC Spares Company Limited]

If anyone has a twin fitted with 2 front heads and 289's, can they tell me which manifold they are using for the rear carb?
Mine has an ET32 which places the carb top so close to the back of the UFM that the previous owner has fitted cables without adjusters in the carb top in order to get a reasonable bend on the cable. This makes it somewhat difficult for me to synchronise the carbs!
Thanks.

Just a small point, there should be no adjusters in the top of the 289's (or 276's) adjusters are always inline in the cables. Synchronisation is as detailed in Paul Richardson's book.

 

[davidd]

Here is what I think you should be shooting for in terms of positioning. It is an original road going Lightning:
Photo1

Photo 2

If you build them from aluminum, I prefer it in two parts, the stub and the tube. You can then weld them together at the angle you want. You will have to go in and smooth the weld, but if you do it in a straight one piece set-up, the carb will be too far in and it will point toward the ground slightly:
Photo 3

Photo 4

David

 

[macvette]

Very impressive. It looks like the fuel gets to rear carb from the top of the central float? chamber. Is it gravity feed?

 

[b'knighted]

Surly that pipe must be a feed fron the righthand side of the tank? It is into the same banjo as the left feed.

 

[b'knighted]

Surely?

 

[macvette]

I think I cracked it. there are two float chambers but I didn't see the rear one at first so you are right .

 

[roy the mechanic]

David, that's one pretty motorcycle! I reckon it may run a bit better if the rear carburator did not face "downhill" regards, roy

 

[youngjohn]

Thanks for all the help - looks like I'd better dust off the old Myford.
I've got a spare 'D' manifold to cut a flange from.
What a pretty Vincent (above) - That's really nice.

Just a small point, there should be no adjusters in the top of the 289's (or 276's) adjusters are always inline in the cables. Synchronisation is as detailed in Paul Richardson's book.

Well that's answered another part of the question. Looks like it's a cable set and a manifold. I still like the idea of the carb in the breeze a bit.

 

[davidd]

I should have mentioned that the shiny one is Bev Bowen's "Felix", which has been featured in MPH. I think I did a thread on this bike which can be found by searching for Bev Bowen.

David

 

[b'knighted]

If you have a D rear monoblock adaptor (ET32 /19) you should only need to turn down the rear flange until it leaves a spigot the same size as your front adapter. So long as you don't cut its back flange off, it should be just long enough for the clip to clamp over. It may still be easier to use the ET32/22 suggested earlier as it doesnt have the back flange being built for a rubber sleeved Mikuni.

From

ET32/22
Rear Carb Adaptor Mikuni VM28/30 & Mk2 Amal
Rear Head, only for Twins fitted with 2 Front pattern heads.

Non-Standard alloy adaptor for 1,1/8" rubber mounted stub fitting carb i.e MkII Concentric and Mikuni.

Not supplied by Vincent factory belived to be unique to The VOC Spares Co