Why does fule pump relay keep blowing?

[giancarlo]

OK, bear with me for a sec. I know this is not exactly a new topic but I have read threads and don't see the specific question I am trying to get at.

1991 907 in the US. Have a problem with fuel pump relay which has happened before. Other day bike was running fine when after a brief stop bike would not prime after turning the key and as a result, no start. After reading through several of the post on this site I went out a swapped relays on my bike (on the left inside fairing by blinker). After putting both relays back in opposite positions bike primed and started right up. Then just for the hell of it I put them back into original positions and bike primed correctly but after priming when I hit the starter button I could hear a slight 'burp' and then bike continued to turn over but without starting. Turned key off and on again and alas, no more primer.

At this point I am hesitant to keep witching relays and taking a chance in trashing them if the problem is elsewhere. BTW, neither fuses on relay nor any other fuses are blowing.

Question is, what component(s) is either up current or down current from relay that could be causing this to keep occurring.

Bike is in excellent condition with 0% corrosion or other suspect maintenance issues.

Grazie mille,
Giancarlo

[blazing928]

it seeems that only one relay is faulty.

When you swapped it with the other one, did the other item work?

It seems just like one relay is faulty, they do die inside, try a new one.

[Derek]

What from what I understand of your description;
The pump wouldn't prime so you swapped the relays.
With them swapped it worked fine.
You then swapped them back and it worked briefly and stopped working again.

I think this clearly shows that the fuel pump relay is dodgy, probably burnt or corroded contacts internally. I'd fit a new relay and take it from there. They are not particularly expensive.

Associated problems which I didn't think you have can be the fuse pump fuse blowing. Either because the filter is clogged or the pump is faulty and drawing excess current. Any resistance at the connectors of the relay socket or the fuse will create heat which can lead to burnt out sockets and melted fuses.

[giancarlo]

Of course, if I can find any more relays I will replace. Anyone know of currently valid part # or replacements available? Hard to find in the US, discontinued item etc. Can these things be 'repaired'?

I assume from reading post here that the relay I switched was for the fan and I did not let bike run long enough to check. I was

A big concern of mine is that this is the 3rd relay for same problem in about 5 yrs. Doesn't it seem that there would be a contributing factor that is not being addressed? And of course they blow when I'm away from the homestead.

If I can get my hands on a 2 new relays I will change both out had see if that fixes problem. If it doesn't I follow Derek's idea of going inside tank and see if there is any problem inside that I can identify.


Also, Merlin Motorsports list a Weber PI-022 replacement fuel pump for the 907 which would cost me less that $200 US delivered. Seems like a good investment if the pump indeed works for the ie.?

Again,
Thanks in advance
Giancarlo

[paso750]

if the pump ever breaks down you can try to fix it
https://www.box.com/s/i8zgqnd7bdye1rofk1bg

G.

[angelix]

The relays used by ducaty are often the same in several models and are also very commonly used on most cars (at least in european cars)

there are few cases (the M900 relay activated by the bikestand switch) where the relay can be found through digikey.com, Newark.com or other electronic components dstributor.

in any case, if you remove the relay and check it you will find all written on it (20-30-40A, 12V, SPST,SPDT, etc etc) then you can go any good spare parts dealer and they will give you a matching relay.

by the way on ebay there are several available (over 600 entries) you just need to check your and get the same type.

[Derek]

Relays are available in the UK here http://www.polevolt.co.uk/acatalog/info_20015A.html
I would think that an auto electrical component supplier in your area could provide them.

[h1a]

Your link seems to show a 4 pin relay?
When i had to change my relays i had difficulty finding 5 pin relays with build in fuse,
what i did was using ordinary 5 pin relays without fuse and adding an extra fuse box.
I also had to swap some of the connectors in the relay holder because of different pin location.

Pics of original relay: