PARUS wrote:I'm not going to do it this year - as far as I'm not going to sell my 400cc for ever - I can wait, but I don't see cb400sf very popular and I don't think we can expect some of them will broken nearest feature. So, for not just collect information which donor throttle bodies I can use for conversion.

If you wait it out some will come up for sale in the near future I imagine. They sell about 500 a year here in Oz. I saw a written off one the other day but it was only being sold only as a whole bike.

Cammo wrote: If you wait it out some will come up for sale in the near future I imagine. They sell about 500 a year here in Oz. I saw a written off one the other day but it was only being sold only as a whole bike.

I'll monitor internet for selling such part - but does anybody know it will be bolt-on...

Here is measurement for GSR400 throttle bodies


Does anybody know - are this so important we have 30mm inner diameter against 32mm on stock carb.

PARUS wrote: Does anybody know - are this so important we have 30mm inner diameter against 32mm on stock carb.

I don't think the size difference will matter too much.

It depends why you want to go EFI? You can get exactly the same peak hp out of carbs, but not the nice power curve, infinite adjustability, economy and emissions out of EFI.

A 32mm intake will 'probably' be better for top end power, but that will only be by a very small amount I imagine and at the expense of low/midrange power. 30mm can easily flow enough for a 400cc engine and will give better response and low/mid power.

FWIW, RVF400 are 30mm carb, VFR400 are 32mm. Many racers prefer VFR400 carbs, but the gains are probably minimal. 30mm RVF400 carbs can be made to perform very well for good power.