Author Topic: Monobloc carb slides  (Read 319 times)

Offline iansoady

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Monobloc carb slides
« on: August 04, 2018, 04:41:45 PM »
My 1952 ES2 is fitted with an (incorrect) 1 1/16" Monobloc 376. It should be a 1 1/16" 276 type but I'm happy to stick with the later carb at least for the time being.

The "correct" settings for both the 276 and the 376 (which is correct for later machines) include a no 4 cutaway. I've found it runs much better with a 3.5 component although the only one I have in my fairly extensive collection of bits is well past its best.

It struck me that perhaps I could skim .030" or so off the bottom flat face of a good No. 4 slide which I have (I understand the numbers increment by 1/16" per whole number).

I appreciate this will probably ruin the slide but as they's knocking on 30 by the time VAT & postage is included I'm tempted......
Ian
1952 Norton ES2
1982 Moto Guzzi V50

Offline mini-me

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Re: Monobloc carb slides
« Reply #1 on: August 04, 2018, 04:48:11 PM »
I think its just the angled side you remove metal from, and 1/16 strikes a chord in my scrambled memory.

Offline TGR90B

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Re: Monobloc carb slides
« Reply #2 on: August 04, 2018, 04:57:21 PM »
Ian, I've got a 376 3 1/2 slide. Pm me your address and I'll send it to you. I have no use for it.
Dave.
Getting grumpy.

Offline iansoady

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Re: Monobloc carb slides
« Reply #3 on: August 04, 2018, 05:06:04 PM »
That's very kind of you Dave. PM sent.
Ian
1952 Norton ES2
1982 Moto Guzzi V50

Offline iansoady

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Re: Monobloc carb slides
« Reply #4 on: August 04, 2018, 05:08:29 PM »
I did find a thread on the Vincent forum where people do seem to have a fairly relaxed attitude to this sort of thing:

https://www.vincentownersclub.co.uk/threads/amal-289-throttle-slide-cutaways.8877/

Ian
1952 Norton ES2
1982 Moto Guzzi V50

Offline chaterlea25

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Re: Monobloc carb slides
« Reply #5 on: August 04, 2018, 09:09:59 PM »
Hi Ian,
If you shorten the slide to reduce the cutaway the needle clip position will need to be moved the same amount
(if you have enough grooves to compensate)
Filing the intake side only will increase the cutaway, the opposite of what you want to do

John

Offline iansoady

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Re: Monobloc carb slides
« Reply #6 on: August 05, 2018, 10:20:00 AM »
Thanks John.

I'd only be taking .030" off which is much less than the difference between any 2 grooves in the needle.....

I was going to skim the slide in the lathe so taking it off the flat end face rather than the angled cutaway so would be reducing the amount of cutaway.

That link I pointed to says that the geometry would be changed as the cutaway normally starts from the same horizontal position at the bottom of the slide hence its angle changes with different cutaway values.

But we'll see how the slide from Dave works.
Ian
1952 Norton ES2
1982 Moto Guzzi V50