The carburetor setup on Tomos A3’s is pretty atrocious. It’s a 12mm encarwi carb, it’s tiny and literally has no adjustments whatsoever. No idle adjustment, idle is controlled by adjusting the tension on the throttle cable. The float bowl is closed by a fishing bobber looking thing with a needle in it, the alignment is easily messed up and it’ll overflow if the petcock is left on when parked.
I’ve got a spare 16mm dellorto sha clone that I’d like to throw on there, but I needed to figure out an intake of some sort. The A3 specific intakes that treats and other places sell are somewhat spendy and since the sha is a clamp style carb it makes making one myself a little tricky.
I figured I’d give the A55 stock intake a shot, I wasn’t sure if the bend was in the right spot, but for $19 I figured it’d be word a shot. Well by default it’s the right size but the bend isn’t in the greatest position, as it is if faced to the ignition side of the engine it points into the cover and if flipped the other way the carb would run into the petcock.
It appears that the bend is connect to the plate just by pressure and a bit of solder. So if you heat it up red hot and put it in a vise you can swivel the bend. Once it cools the solder will harden up again in it’s new spot. If you face the bend directly over one of the plate’s bolt holes it’ll be pretty much where you need it to be. You may have to teak it a little bit more, there not much wiggle room once it’s in the proper position, only about 1-2mm between the top of the carb and the frame and the same below the float bowl and the ignition cover.
After a few tries you should have it in the right position and be able to connect a sha or a bing.