Hitchcocks Forum

Does anybody know if the T3GP2 Amal 1'1/2' carburettor can be converted to run on Methonal/Ethonal , Here in Australia you can buy E85 fuel at the pump , thats 85% Ethonal 15% petrol . I bought the Amal Mk2 Concentric 32mm for my ported almost full race 1995 Indian made engine ( now 612cc ) , apart from having to raise the rear end of the fuel tank to give the throttle cable room..... but I am thinking about converting the bike to a Fury replica and with the big head comes a few problems , can the T3GP2 be converted ? No Methonal parts are listed so can the parts off a 38 mm Amal smooth bore be fitted to the T3GP2 ? If not I will have to fit a MK 2 smooth bore and with the special 38 mm flange adaptor the carb will be in a possition where the cable might clash with the Fury fuel tank or might even put the cable in a possition where it is not even under the tank but outside the tank recess and will mean a Velocette Thruxton cutaway will have to be made to the tank and that will add to the cost of the conversion which I am trying to work out . The other thing is the angle of the semi down draft angle of the Fury head inlet port which might be too much for a MK 2 concentric to cope with .

The GP carb just needs a suitable needle jet and main jet, no other changes are needed. Here is our short stroked Big Head 350 running on methanol, with 1 1/2" GP carb fitted. Cheers, Paul.
https://www.youtube.com/watch?v=4UBGemFDyTM

Phil,



if you still have any doubts over the use of (mostly) ethanol fuel after watching B.W.'s video the current manufacturers of the Amal GP3, Burlen Fuel Systems in the UK, should be able to advise you.



http://burlen.co.uk/contacts/



ISTRC our hosts mentioning that the Big Head fouls the underside of normal Indian Bullet tank, so getting the tank modded might be needed anyway, unless you're using the Redditch-style small chrome panel tank (also made in India, these days!). I assume this is the tank you mean when you refer to the Fury tank. If so the GP carb seems to fit OK from the examples I have seen.



With the Mark 2 Concentric the style of carb mounting will affect the cable run. Surrey Cycles over here make a one piece mounting rubber/flange which is quite compact and will probably keep your carb from sitting too far back, which is when cable fouling issues will arise.



http://surreycycles.com/product/mkii-adaptor/



If however you're using a separate alloy mounting stub with a rubber joining sleeve this WILL put the carb further back, and if that does cause throttle cable routing problems, don't despair, rather than costly tank modifications there is an easy solution, get an angled cable ferrule to screw into the top of the carburettor to point the cable away from the underside of the tank. You will have to shorten the outer throttle cable to compensate, a fiddly but not too difficult job. Your nearest Dell'Orto stockist should have a range of ferrules with different degree bends, AFAIK they have the same 6mm thread on the carb tops as the Mk2 Concentric. This is the 90 degree version.

http://www.dellorto.co.uk/shop/dellorto ... elbow-kit/




I'm going down a slightly similar route for my current project (or will be once the previous project stops sulking), using a Dell'Orto PHF38 carb which is a bit bulkier than the GP3, and that will definitely be using a cable ferrule!



hope this helps.



A.

Thanks for the advice guys it helps me allot .