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Bike Fuel Pump - Whats Wrong?
RichieC - 1/6/06 at 07:07 PM

Hi all,

Starting to pull my hair out. What am I doing wrong?

I confirmed the pump which came with my engine was knackered but having tried the replacement and a loner from a mate, neither will run. They are popping the fuse and when you put 12v directly across them, they dont run.

Surely they should rumble away? Surely I havent got 3 duff pumps?

Is 12v direct too much current or something? Ive had a look at the sprung terminals inside and they look clean but are together. You can pull them apart but the click back - ie they wont shuttle.

Am I being a total monkey cos as it stands Im going to have to fit a facet and bu66er about with a fuel pressure reg.

Rgds
Rich

[Edited on 1/6/06 by RichieC]


stevec - 1/6/06 at 07:26 PM

What rating is the fuse?


coozer - 1/6/06 at 07:32 PM

They will only run when there is negative pressure in the fuel line. By that I mean below the required preset pressure.
On the bike they stop when supply pressure is sufficient. This prevents the carbs flooding.
Make sure there are no blockages in the fuel lines or around the pump.


RichieC - 1/6/06 at 07:42 PM

Its a 15A fuse but this is with no fuel lines connected ie sitting on the bench and connected directly to 12v

[Edited on 1/6/06 by RichieC]


shortie - 1/6/06 at 08:03 PM

I think I'm right in saying that you shouldn't run them with no fuel going through them as it causes them to sieze, I think it's that the fuel lubricates the pump.

Rich.


RichieC - 1/6/06 at 08:34 PM

Thats correct 2 seconds wont damage it though in testing.

Thanks

Rich


stevec - 1/6/06 at 09:34 PM

Ive had my bike pump clicking away for short bursts with a similar rated fuse,is it possible that it has been left on while you have been doing other electrical stuff and knackered it,


muzchap - 1/6/06 at 09:38 PM

Knackered 3 though? In a row? Odds seem a little high!

Right how you connecting it to 12volts? Are you using a car battery? If it's blowing 15 amp fuses that's worrying...

You are connecting it the correctway round? Just a suggestion! easy to do!


RichieC - 1/6/06 at 09:40 PM

No, it was straight out of the box.

I just tried a low output battery charger. It is [the charger] clicking in and out in the same way it would if you shorted the + and - together as if theres an internal short.

Rich

[Edited on 1/6/06 by RichieC]


RichieC - 1/6/06 at 09:42 PM

quote:
Originally posted by muzchap
Knackered 3 though? In a row? Odds seem a little high!

Right how you connecting it to 12volts? Are you using a car battery? If it's blowing 15 amp fuses that's worrying...

You are connecting it the correctway round? Just a suggestion! easy to do!


Exactly - too high odds Id think. Yeh polarity is definately correct. Its obviously drawing too much current for whatever reason maybe through a short inside (you cant see much even with the plastic cap off)


muzchap - 1/6/06 at 09:58 PM

The battery charger is probably not the thing to test with...

My pump needed a REALLY good earth and a good power supply to work - we kept thinking it was dead/seized etc..

My advice get a well charged car battery - fill the pump full of WD40 and then test it that way. Messing about with car battery chargers just isn't the way forward - I bet it works fine on a car battery, full of WD40

Just my opinion - but I'm an eternal optimist!


RichieC - 1/6/06 at 10:00 PM

It doesnt Im afraid.

Surely a charger supplies a good earth?

I appreciate a charger isnt the best option, but it is protected so you cant do any damage

I thought it was maybe a stuck internals problem. You can suck on the supply line and blow into the feed line so its working correctly in that sense. You cannot suck/blow in the opposite direction


R


marc n - 1/6/06 at 10:04 PM

we have had this a few times, seems to be if the pumps have been off the bike for a long time they sieze up.


RichieC - 1/6/06 at 10:12 PM

Just cleaned the brass contacts with some wet and dry and carb cleaner, plugged it in and gave it a tap with a rubber mallet while it was connected and its sprung into life.

its still popping fuses when connected to the loom and theres no short or anything on the loom. Its as though its reluctant to pump from the tank and its drwing too much current. I know its a long way to pump but surely with no pressure in the supply line it shouldnt struggle at all.

For info, its mounted just under the tank so is gravity fed.
Rgds

Richie


Ferrino - 2/6/06 at 11:26 AM

the bike fuel pumps must be low current in normal operation as the wires from my R1 relay assy to the carbed pump are a really small gauge.