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Comet Monobloc Jetting

Gerry Jenkinson

Well Known and Active Forum Website User
VOC Member
I am replacing the very worn original Carburettor on my '52 Comet with a new Monobloc. I would like to use the new 229 but the Monobloc is affordable. Concentric is cheaper still but I am used to monoblocs as the D has them and parts are interchangeable. I have heard the monobloc is a tight fit under the tank.

Question is what jets.
Riders Handbook and Richardson say
Main 200
Slide 29/3

KTB on "D" Monoblocs
"Pilot Standard was 30, but 20 or 25 may give better tickover."
"Main can usually be increased to 270 from 250"

1950 Comet with Monobloc. R Swannick
Main 280
Pilot 30
Needle 106
He reports better acceleration and 75 miles to the gallon

I have also heard an increase of the main to 210 is recomended, all advice welcome
Gerry Jenks
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