Can I use 1A1 Carburetors on RD350

[KANDY]

Hi All,
Did anyone used 1A1 carburetors from RD400 on 73-75 RD350.
Is it advisable, may I know what modification for using on stock RD350

[rodneya]

I bought a set of RD400 carbs that already had the Dave F mod done to use on my 350. All I did was remove the breather fittings from the bowl and clock them off.
They are basically the same carb as the 350, they just have the little hole near the top to sync your slides

[KANDY]

Thanks for the Reply.
I got a pair of good 1A1, Thought I can give to my friend whose RD350 Carb is not in good condition.

[Yamaha 179]

You shouldn't block off the float bowl vents.  You should run a short - about 4" long piece of fuel line up towards the air box.  That vent is to equalize the air pressure between the float bowl and the atmosphere, IIRC, and is necessary for proper fuel flow.  I have done hat on all my 1A1 carbs when I remove the air box and use a Y boot.
Lyn Garlsnd

[rodneya]

Mine already had a Dave F mod with an air jet instead of the brass ball. Thats why I blanked them