F40 4 stroke Carbs ?

[Hollowman]

Below is a link to the parts blowup for a 2000 Yamaha F40 3 carb assembly.

Can anyone tell me what is the function of the part described as "diaphragm" REF part # 32 .,,, Or what can result if it goes bad? (You may need to zoom to get a good look at the parts)

There is only one of these on the assembly of 3 carbs. On the bottom carb:
Link:
OEM Parts

[exeter27]

If it's like other engines/carbs I've worked on, it closes the throttle more slowly should you suddenly pull back on the throttle. I believe that's to address emissions. If I'm right, it affects emissions only and not overall operation of the engine.

[boscoe99]

It is also known as a dashpot. It slows down the closure rate of the throttle to prevent a motor from stalling.