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TWO PUMP'S AS ONE
roadrunner - 24/1/07 at 09:32 AM

I've had problem's with my bike pump cutting out mid journey , and had to revert back to mechanical pump, would anyone foresee problem's if i ran both pump's at same time, do bike carb's have a float system to shut of the flow of fuel.


Cheer's Brad.

02GF74 - 24/1/07 at 10:54 AM

quote:
Originally posted by roadrunner
do bike carb's have a float system to shut of the flow of fuel.
yes they do.

quote:
Originally posted by roadrunner
would anyone foresee problem's if i ran both pump's at same time,


in the older days, the fule was gravity fed from the tank that was above the carbs, these new fangled bikes have airbox there and petrol somewhere else hecne the need for a pump. Only problem I can see is the pumps working against each other perhaps i.e. one may want to pump fuel past the other but don;t really see that happening. The electrical one should stop when there is enough pressure but the mechanical one won't, again I don't see a problem with that.

HAve you considered a Facet solid state pump? about £ 30 or else get a pump form a scrappy?

BenB - 24/1/07 at 12:01 PM

The only problem with a scrapper (presumably car) pump would be that bike carbs like bike pumps (all to do with different pressure / flow rates). You might find things got worse by using a car pump (might not though!!)...

roadrunner - 24/1/07 at 12:11 PM

the car does seem to run better with bike pump , but i thought if i leave car pump connected as well , it would act as a back up.

the_fbi - 24/1/07 at 03:25 PM

When the bike pump cuts out, does the car cut out too?

The bike pump is supposed to sense pressure and stop, then restart when it needs to.

No reason why the bike pump shouldn't work 100% on car carbs rather than bike carbs.

As mentioned above, I woulnd't like to put a non bike pump onto carbs as they will most likely over pressure or be regulated so low they'll underfeed the carbs.

roadrunner - 24/1/07 at 04:01 PM

The bike pump has cut out a couple of times , twice due to blocking up, sorted that, and once for no apparent reason, i think it might be because it's strapped directly to the chassis, it's been reconnected now and seem's to work, i just need a way of fixing it vibration free.

quote:

TextWhen the bike pump cuts out, does the car cut out too?

Yes , because the carbs are starved of fuel.

jacko - 24/1/07 at 05:13 PM

Hi Brad don,t be tight get a new one


could it be a faulty electric plug - fuse holder - is it definatly the pump
Graham

[Edited on 24/1/07 by jacko]

roadrunner - 24/1/07 at 06:41 PM

definately the pump.

Cheers Graham.

TangoMan - 24/1/07 at 06:54 PM

If you pipe both pumps in series then the lesser pump will be irelevant as the higher capacity/pressure pump will take over.
It would mean that if one failed the other would still be there as backup and it would cause no ill effects running both.
I just ran the mechanical pump with my R1 carbs n the Pinto. No problems in 5000 miles.

stevebubs - 26/1/07 at 10:19 PM

quote:
Originally posted by TangoMan
If you pipe both pumps in series then the lesser pump will be irelevant as the higher capacity/pressure pump will take over.
It would mean that if one failed the other would still be there as backup and it would cause no ill effects running both.
I just ran the mechanical pump with my R1 carbs n the Pinto. No problems in 5000 miles.


Unless the combined pressure is enough to overcome the regulator....then you'll end up with your float chambers being overpressured...

britishtrident - 27/1/07 at 04:51 PM

quote:
Originally posted by stevebubs


Unless the combined pressure is enough to overcome the regulator....then you'll end up with your float chambers being overpressured...


No Tangoman got it right
Dosen't work that way in all diaphragm fuel pumps (electrical or mechanical) the output pressure is limited by the rate of the spring that returns the diaphragm.

In effect the output pressure is pegged relative to atmospheric pressure.

Putting two pumps in series dosen't alter this the peak output pressure cannot be higher than that that of the highest rated pump.

mr zefect - 27/1/07 at 10:46 PM

My mate had the same prob it would just cut out when it felt like it we got another pump and has been fine.