I've got a Mikuni carburetter on my A65 Thunderbolt. In my opinion the 'idling' is better as an Amal concentric.
Is it possible to fix a Mikuni on my M20? What type, bore? And what are the carburetter settings?
In my garage I've got a 'MIK' carburetter 24mm ( Enfield Indie 350cc). Should it be possible to use this carburettor on my M20?(with larger jets)
I hope someone can help me.
Thanks and BSA regards from Belgium.
Eric
I will admit I did do such a thing.
I will also admit I have since put it back to an Amal.
What I did was strip down some ZX250 carbs into just one carb, and then made a flange, of a piece of plate steel, a small piece of pipe, and some more plate. The idea is it gives you a surface to bolt onto the studs on the cylinder, and another to bolt the carb to. The inside diameters is around 30mm - so it all meshes fairly smoothly.
As for operation, it ran a little lean on stock jets, but made really good power.
I wont do this again as it detracts heavily from the appearance of the bike - I just needed a temp fix until I sourced and ordered a new carb, and waited for it to show up.
Thanks Brad J. for your comment.
I hoped to get more information from other M20 owners, but I can understand the reason.
In UK you like restoring M20's with genuine parts, and I know that's the best. You all own lovely bikes and all in very good condition. I love these bikes.
But for me (in Belgium)it's not so easy and somethimes very expensive to find ginuine parts. And it's a hobby.(to restore in winter and ride in summer) At this moment I'm restoring an M20 (basketcase).When I'll buy a new carburettor, an old Smith speedo meter, a rewind magneto, it'll cost me more as 700 Pounds, and that's not all,there are more costs!!!
That's the reason I'll try to fix an Indian MIK carburettor on my M20.
I hope you all can understand this reason
Regards from Belgium,
Eric
Hi Eric...there is no reason the carb you have will not run on an M20. Ideally the choke size (the hole through the carb) should be about the same size as the M20 (1" or 25.4mm)
If it is larger than that it will affect the sizes of the jets but should still work.
I have not run one of these myself but the way to set it up would be to overjet it (ie set it rich) and then reduce the jet sizes to obtain the correct mixture.
As these carbs were fitted to Indian made Royal Enfields you should be able to get some jetting information from a good Enfield dealer. I would start off with it set up for a 500cc Enfield and run it on the bike to see how it performs. Jet sizes and settings could then be adjusted to richen (but more likely weaken) the mixture as required.....Ian
