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Has any body put a monobloc carb on a Scott, was it ok , what size did you use and what size jets/ slide and needle. I need a carb for my Scotton , Ive already got a aluminium adapter.
Not on a Scott maybe but I did once put a monobloc on my old Vincent Comet. I still have that carburettor buried somewhere but I can’t remember how the jets/slide setup compared with the original carburettor, (well it was over 40 years ago!), and even if I could find it I doubt it’d help much help other than to say that it worked.
Good information on changing carburettor types and fitting equivalent internals seems to be in the hen’s teeth range of availability. A point to bear in mind however is that the two types work much the same way. Jets, slides, etc as you know come in a range of sizes/shapes so if you find the point in the range where the original component sits and then find the same point in the monobloc range you should at least have a starting point. The rest will be a matter of swapping components and road testing to find the ones that best suit your machine. If you aren’t sure of the standard components I’ll dig out my unused standard Scott carburettor and put them on here. Choke size should be the same I’d have thought, as you need the same mass flow.
Finally I did find that I never could get as good mpg figures from the monobloc as I did from the standard carburettor, (85 mpg on a gentle run and never less than 73 mpg around town), the monobloc was about 10% greedier but performance was equal.
There is a Scott carburettor body, (no float chamber), on eBay (number 150170457545), any use?
Hi Eric, one of the best things you can do to a scott is fit a monobloc carb, the beauty of this type of carburettor compared to a concentric is that it can be tilted to the scott downdraught whereas the concentric has a limited angle and needs a curved manifold, I ran my birmingham on the following settings, 1&3 sixteenths bore 389 monobloc, D needle 105 needle jet,3slide, 340main jet, this might not suit your engine as I had other tuning mods, I also believe in not running a two stroke too weak especially a Scott which suffers from poor piston lubrication, good luck. Alan Noakes.
Thanks Alan, Ive got a 389 on the shelf from a bsa
Hi, I realise this is an old issue but would be interested see if anyone has anything new to add to this. Jeff Reed
Yes Jeff it would as I am shortly going to put one on my B/ham. Eric