TT to Monobloc 389 jet sizing?

Information relating to the Matchless G85 500cc Heavyweight, AJS 7R, Matchless G45 and Matchless G50
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TT to Monobloc 389 jet sizing?

Postby Matchymarty » Wed Sep 26, 2018 12:57 am

Hi all,

Just wondering... does anyone know the approximate TT to Monobloc jetting conversion ?

Further to information posted here on my other thread, it seems that my '55 G80CS came out with a TT carb and a 340 main. My monobloc is also a 1 3/16", and so was wondering if there is a conversion that might state what my jet should be?

(I realise there is info there also for the 'G80S' for 55 that states a 389 Mono witha 250 main. However, that is also a 1 5/32" throat.).

Just wondering....

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Re: TT to Monobloc 389 jet sizing?

Postby cbranni » Wed Sep 26, 2018 8:38 am

My 1956 G80cs runs on a Amal 389/12, 1 3/16 bore. 30 pilot, 3 cutaway, 440 main jet, 106 needle jet and needle position 3.

It,s performance regularly scares the pants off me.

Hope this is of some help.

only dead fish go with the flow

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