Hello, just wondering if when putting a 28mm ( fiat 126) carby on a stock 500 engine, do i need to change the black baseplate that the carby rests on also?
Thanks guys.

Yes, I would advise fitting a 28 mm spacer witha 28 mm carb

Thankyou, will do so.

How does it affect if you want to change a 28IMB to my stock engine. These are more at ebay etc and cheaper. Does it run well? Just wondering...any benefits or "problems". Just bolt on and go(only spacer)?

I do not have any experience in doing this, but the idle jet might be too big. This is the jet screwed into the carburetor about 30cm above the idle mixture screw. You may have to use the jet from the 26imb.

John

I believe Jacob is right about the jet screw. On another note the 28 might be too if in general for an engine that small that isn't tuned correctly. The bigger the carb, the more fuel in your mixture which means you you could be burning rich. That decreases your fuel mileage and could possible result in a loss of power.