Fuel pump not priming - help please

Cefn Coed

Hi

The fuel pump on my 888 is not priming when the ignition is switched on, it hasn't been run for around 3 months and was very low on fuel. Bike hasn't been used for a couple of years and just run every so often, probably not as much as it should have been 😩

Please can someone offer advice on diagnosing the problem, is it likely to be faulty fuel pump?

Thanks in advance

David

marvin

Check to see if it's getting power. If not it may be a relay or just a bad connection. If it is getting power but won't run it is probably stuck. You can put a little fuel injector cleaner in it and it may free up. You can also reverse the polarity of the current (DC motor so just turns the opposite direction) and it may spin up.

Cefn Coed

marvin wroteCheck to see if it's getting power. If not it may be a relay or just a bad connection. If it is getting power but won't run it is probably stuck. You can put a little fuel injector cleaner in it and it may free up. You can also reverse the polarity of the current (DC motor so just turns the opposite direction) and it may spin up.

Thanks will try as suggested

brad black

giving it a knock with a piece of wood is also often effective.

Cefn Coed

brad black wrotegiving it a knock with a piece of wood is also often effective.

Tried that and didn't work LOL

stiglarsenDK

New one most likely

Chances are that you need a new one .. I had a box of old pumps , only half was working .. before you do stick your arms into that nasty hole, check your relays and these (blue 15A siting at the console in the back end above the tail light.. good luck 👍

Cefn Coed

stiglarsenDK wroteChances are that you need a new one .. I had a box of old pumps , only half was working .. before you do stick your arms into that nasty hole, check your relays and these (blue 15A siting at the console in the back end above the tail light.. good luck 👍

Thanks for advice, the 2 relays under the seat seem to be working, can feel them switching when ignition is turned on and fuses are all good, will try and have a look at weekend and see if I can identify the issue thanks again for the advice

stiglarsenDK

Hit it one more time , hard

I will bet a pint it's a new pump ..,anyway a fresh pump will make it go another 25 years , Money well spend IMO

MarkT

David-

The small Walbro pumps on the 888 are very inexpensive so I agree with Stig and others that buying a new one to check out is not a financial stretch. In the US the common pump used in an older Ford Mustang is the normal replacement many have used.

If you had an 851 with the larger Corse (also early BMW K bikes) then buying one just to check out is much more expensive. (although there is a very cheap Chinese copy you can buy on Ebay)

On the other hand, the large pumps are easy to take apart and free up the spinning rotor and put back together. I have done this to two of these larger pumps and they worked fine.

You may be able to free up your pump is to soak it in denatured alcohol which seems to loosen up old dried up gas which I have found to be the culprit.

I have cleaned my large pumps with alcohol when apart and will now try soaking a pump first before I take it apart.

Cefn Coed

Hi thanks for the advise, mine is a 1993 model so I think to larger pump type so should be cheap to sort, will remove pump at weekend after checking I have power to the pump and will change pump if I can't free up, it's really strange because it worked fine a couple of months ago and I think will be due to fuel going off thanks for advice David

Cefn Coed

Hi

Thanks for all the replies, I work away during the week so can't look at the fuel pump to check type, I would like to order a new pump to fit at the weekend, I have found one see link below, is this the right pump for a 1993 888?

https://www.glencoeltd.co.uk/walbro-aou195-in-tank-fuel-pump-aou034/

I can see some on eBay but they look like cheap copies and would require wiring changing to fit, I assume the ones on eBay would not be best option?

Thanks
David

Cefn Coed

How do I remove the top of the tank?

Hi

I managed to start work on getting the fuel pump out, I have removed the filler cap and the small grub screws, apart from one that will not budge and the hex has rounded.

Will the tank top come out with one grub screw still in place?

If not any ideas on how I can remove the grub screw?

Thanks
DAVID

marvin

Hi David,

I doubt that it will come out with one grub screw still intact. They come out hard at best. Especially if it has not been out for a while and not greased well.

You can try putting a coarse valve grinding comound in the recess. Sometimes that helps the allen key grab better. You can also try jamming a larger allen key in it (like a slightly larger SAE key).

griff851

When any screw seems overly tight, before applying too much torque that strips the hex, slot or whatever, put the drive in the screw and give it a tap or two with a hammer. The downward force flexes the thread slightly which un-binds the threads. Then if that fails soak in wd40 and come back next day and tap again. If you mang it up so much that Marvin's suggestion doesn't work, it's drill and easy-out time.

Cefn Coed

Thanks for help. Will have another go tomorrow when soaked over night in wd40

Thanks again
DAVID

griff851

Ps, you can't get the force transfer by hitting an Allen key on the 90° bend. You'll have to cut it to get a straight shaft. Allen keys are cheap.

Cefn Coed

griff851 wrotePs, you can't get the force transfer by hitting an Allen key on the 90° bend. You'll have to cut it to get a straight shaft. Allen keys are cheap.

Good point, I will cut an Allen key so I can knock in better, I have ordered some small extractor tools, not sure if will work, I think the grub screws are stainless steel so not the easiest to drill or get the extractor to grip onto 😩

Interestingly the pump is actually working but very slow, either clogged or not enough power getting to it, I assume would be ok to put 12 volt direct to the pump before I remove just to confirm not a bad connection?

griff851

Sure, a suggested earlier even swap polarity to run it backwards, just don’t run it for long dry. Short bursts. Might have gunge in it and you might get lucky.

Cefn Coed

In the tank now

Hi

I have managed to remove the fuel cap base and have now managed to remove the filter and pump.

Pump is now working ok, didn't do anything other than remove the pump and reversed the connections, interestingly the pump sounds like it is running fast when reversed. I have ordered a replacement pump, seem sensible whilst I am in there 😀

Found some hard matter in the bottom of the tank, see picture, other than these bits, the tank is very clean

The pipe the second picture was full of rust, it's the one that clearly looks rusty, am I correct this is just the drain from the filler cap base and should be free flow, it is currently blocked and assume the rust is the issue, will try to blast out with compressed air

Thanks
David

Cefn Coed

Seal tank or not?

Now that I have the tank internals out, should I seal the tank, it is in very good condition, only a small amount of corrosion in the bottom, interested in hearing people's opinion on this

I have looked at this product https://www.frost.co.uk/por15-car-bi...iAAEgJ_1_D_BwE

Thanks
DAVID