Fuel pump failure and fix

All,

I mentioned briefly in the Nathan Woods ride day thread that my fuel pump had gone out during the ride. Well today I was able to find the problem and fix it.

I had first checked to see if I was still getting voltage at the plug for the fuel pump, which I was. Once I got the tank off I was able to get to the two prongs up inside the connector and using my ohm meter I found the circuit to be open.

I pulled the tank off and found the ground wire disconnected and just hanging there. When I put it back on the connector was loose. So, I tightened up the connector by sort of crimping it down, but, when I put it back on it still did not have a snug enough fit for my liking.

So I crimped it down some more, and then used .027" safety wire to wrap around it to tighten the grip the connector had on the blade, as well as wrapping it around the connector up higher and then tied it down to part of the pump housing to keep it from coming off again. I did the same for the positive side for good measure. I have included a couple of pictures but they are not the best quality. However, you get the gist of it.

Put it back together and had the fuel pump running and the bike started right up! If you look closely at the top photo you can see where I drilled the fuel pump holder right over the plastic tangs on both sides that hold the assembly in the holder itself, then installed a #4 wood screw on each side. There have been a few reports of fuel pumps jumping out of the stock housings leading to failures, so when I put my sub frame fuel tank on I went ahead and added an ounce of prevention to the aluminum fuel pump adapter that we supply.

Hey Dale, Apologies if this is a dumb question (I have not had a look in my tank yet), but are those 2 wires immersed in the fuel? Just thinking of the sparks in the tank when the wire was loose.
Davo

Yep, they are totally immersed until you get low on fuel. Sparks shouldn't be a problem as the mix is too rich to ignite, no 02. Still not something you want happening!

Hmmm that is a little scary. The tank is a bit close to the crown jewels too :williamshatter:

Davo said:

Hmmm that is a little scary. The tank is a bit close to the crown jewels too :williamshatter:

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One day, I will regale you all with the story of my childhood ride(an XL 75), a defective cork fuel cap gasket and my tendency to ride too far up on the tank.

To this day, you will still find me sitting on the rear fender when I ride.

DaleEO said:

Yep, they are totally immersed until you get low on fuel. Sparks shouldn't be a problem as the mix is too rich to ignite, no 02. Still not something you want happening!

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It seems wise to never run on empty. A tank full of nothing but fumes could make a nice bomb.

Thanks for catching this defect and suggesting a solution. I wish I had know two days ago - I just installed my Profill filter (the stock filter was totally gummed up from the factory). I think when I first check my valves (I only have 0.8 hours on my bike so far) I will check the new filter and add these safety wires and screws.

Personally I soldered my wires on when I saw how whimpy the connection is. No worries then. BTW... for you worry warts... you're probably driving a car with a fuel pump and wires in it's tank... no biggie.

Busa10 said:

Personally I soldered my wires on when I saw how whimpy the connection is. No worries then. BTW... for you worry warts... you're probably driving a car with a fuel pump and wires in it's tank... no biggie.

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Just that the 1 or 2 in tank EFI pumps I have seen in cars are not push on connectors. Not that I have seen too many in tank pumps.
Will be soldering mine too if I ever get my bike back. Thanks for the tip.

This looks like an obvious design fault from what ive seen and heard about this problem and im a bit concerned about it as ive recently bought a 2011 570.
My mate bought the first of the 450s and we went to collie motocross track for an over nighter with a few boys ,anyway he just recently put in the low fuel light sensor in the tank and whilst he was going round the track it died on him luckily he wasnt approaching a jump or halfway through a jump could of been carnage.
We wheeled his bike back to camp and pulled it apart and one off the wires came off the fuel pump.
So when you remove your fuel tank for numerous types of serviceing you need to disconnect these wires alot during the bikes lifetime so you prey that they dont come loose while your going through a set of whoops at 90+km an hour
because it would be goodnight irene for you and your bike when she cuts out.

I would add that there is a lot of fuel line inside the tank, has to be to be able to pull the stuff out either end. And this has a lot of mechanical effect on stuff flopping around.

The connectors rely on a very small pin in the slip on connector to pop into a corresponding very small hole in the blade to hold it. On mine this tab that has the pin had lost most of it's "spring" effect and would not lock into the hole.

Probably the best solution is what Busa did, solder your wires on as a preventative fix.

Although I feel pretty confident of my safety wire job, and the fact I also tied the wire bundle with a ty wrap to the return fuel line, after pulling down some slack on the wire bundle.

You could also probably just run a piece of safety wire through the hole in the spade and wrap it around the connector and then tie it off on the wire just above the connector itself.

Few days ago I had problem with ignition on 570 and at the end I discover that problem was broken spark mounted one week earlier. Anyway, looking for similar problems I was browsing this forum and found this thread. It seemed to me that many people had/have some problems with fuel pump so I was bit surprised that we never had anything similar (390, 450, 570). But, yesterday evening coming back home my 570 just stopped. Luckily, it was moment before I wanted to jump. :mrgreen: Thanks to this thread, first thing that came to my mind was wire problem due to the fact that fuel pump never shows any signs of malfunction. After opening I could only confirm situation as DaleEO described. We used similar "wire technique" :mrgreen: but more or less now looks pretty much the same. Anyway, thanks for posting, you saved me time and money, but most of all, bike is ready for week-end. :mrgreen: :cheers:
Greetings from Zagreb, Croatia.