While going through the carbs, I've found the second's diaphragm spring is about 4 coils shorter than the other three. My question is for a replacement, are there any other known bikes out there that share similar if not the same diaphragm springs for a stock 3EN1?

I've noticed that with the airbox off, the second cylinder lags when opening up the throttle. Idk if the spring might have anything to do with it, or if that's just a balance issue.

Thanks

I'd say it will make a difference, just not sure how much. FZR600 3HE used similar if not the same carbs as the 400, obviously the settings are different.

The £HE is a bigger capacity version of the 400, the crankcases are common and you can fit a 600 engine into the 400's frame fairly easily

Shorter.Softer spring,Will cause the slide to return at a slower pace,
Therefore being out of sink with the others.