Almost finished building a locost CBR1000 but having problems with the float chambers overflowing at high revs. I am running an MGB fuel pump but suspect, as I have read on this forum, that the pressure it delivers is too high (the pump is an interupt type).

Does anyone know what pressure a cbr1000 carb system should run at?
Would I be able to correct the problem with an off the shelf regulator?

Thanks!
James

Hi mate,

I had to fit a bike pump to my set up (zx10) as the pump I orginally had was producing to much pressure and causing the carbs to flood.

I'm sure the bike pump runs at 2/3 psi max.
As for the regulator,I have no idea !!

If it was purely a fuel pressure problem it would occur at idle not high revs.

I suspect the root cause may actually be a carb vibration problem check your carb antivibration mountings are as the engine manufacturer intended.

It may also be you have fitted a high pressure pump, different springs are available for SU pumps you could try fitting spring part number AUA1449 which is avialble from Burlen Services for about £1.50 + vat & p&P

99% of problems when running engines fitted with bike carbs go away when the proper fuel pump is fitted.

Although it should be possible to "adjust" the fuel pressure etc of a car fuel pump it's simplest just to fit a bike fuel pump. Cheap as chips anyway....

is this the same with a zetec engine running on bike carbs? should i use a bike pump or a car pump?

Cheers for the feedback chaps, I have a 1 5 psi regulator which I will try and also I will try to get a bike pump.

James

Chaps

I am still having problems with my carbs flooding. Here is the situation:

1. I have tried using a 1 - 5 psi regulator with the MGB fule pump - carbs still flood.

2. Tried a friends bike fule pump, he is using on a BEC 900cc fireblade - still floods.

3. Cleaned the carbs out & adjusted the float so it closes earlier than before - still floods.

The engine is set so the sump is level, even if i take the carbs off & change the anlge they sit they still flood.
I am taking the carbs to a bike place tomorrow to see what they say.

If anyone has any more ideas I'd love to hear.

Cheers

James