Later model carb inlet rubbers

[jdugen]

Hi
I'm still hunting for the cause of the 3K stutter on mine. Reading through reams of posts via Google I have come accross a post that says the later bikes have a modified carb rubber. This, it would appear has a restriction built in that is supposed to increase airflow at low revs. It would also appear to reduce or eliminate the backfire into the airbox. I've not come accross anyone else mentioning this, so, is it snakeoil?

[tony.mon]

As fr as I know all carb rubbers have an aluminium flat washer in, but most people pull it out.

Although there could conceivably be an advantage in increasing airflow in terms of stopping the airbox cough, why not pick up an unmolested set and try it?

[oldbikeman]

Only later bikes should have this.It is meant to increase negative pressure in the inlet tract at low rpm to improve carburation and increase mpg.It is not very effective,removing it will not give much of a rpm increase.

[Stratman]

Earlier bikes were meant to do around 155mph, later ones 143 with a 10 bhp reduction, so this restriction may make quite a difference. A bit of popping and burbling is all part of the fun, after all.