Hey all
1st maiden trip off for an MOT and I failed. Managed 10 miles before cut out, I listened straight away at the tank after a start button blip and no fuel pump spinup. So I managed to push it to a nearby garage where I bought some fuses the smallest in the pack being 15amp. The original in the slot was 7.5 so I wasn't happy putting it in there but I didn't have far to go. It got me 100 yards and blew again.

I got recovered by some kind friends with a trailer and got it home safe. So I've ordered a fresh pump,  mounting hardware and all I need internally to put it right. I was using a fuel pump from my old subaru and it just drew to much current and I don't trust the standard wiring to be able to deal with the extra current draw. I will measure the load after I've removed it as I think it's still working OK.

I wondering about the fuel pump relay and if any damage was done running the wrong pump. If after I've swapped the pump for the right one I wouldn't expect the fuse to blow again. If it does other than the relay is there anything else that could cause it?

I'm keen getting the brick back flying and attaching the sidecar chassis I have ready to find a body.
Thanks in advance.
Mark

Model and year?

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duck wrote:Model and year?

(The forum Nazis will tell you to put it in your signature.)

1989 k100rs special edition.

Fuel pumps are cheap as chips, but in all my Ks I replaced everything inside the tank, pump, filter basket, fuel filter, pump mounting and the damper and all new pipes. All in cost for me was about 120 euros.   While you are at it get a fuel cap kit too and replace the seals in it and also the gasket under it. Dont buy a used pump.

The fuel pump relay is not unique to Ks as it is also used in several cars. It's rated for 40A so I highly doubt it was damaged when a 15A fuse blew.

So today I replaced everything in the tank, put in a new 7.5amp fuse and it went well for 10 minutes. It fired up fine and idled fine on the choke till it was warm enough to idle itself then blew the fuse, I swapped out another 7.5amp and it blew as soon as I pushed the start button and again fresh fuse and pop as soon as I press the button.

I've drained the fuel ready for tomorrow's tank off so I can look at the relay box.
So I've joined the 7.5amp fuse blowing club.
The 4 pin plug has already been chopped off and the power to the pump goes via terminal block, the fuel level sender has been deleted already.

I'll go read some threads but I'm fast loosing the will to carry on breathing life back into this bike.

Good news, after removed the fairings to check for a kinked pipe on the left and to unplug the temperature sender the other side I found a chaff'd wire. The positive wire to the fuel pump was the culprit, it didn't pop the fuse with the tank disconnected so I examined it closely and saw it.

The bike didn't want to run with the temperature sender unplugged so I plugged it back in, I also took the ball bearing out of return incase that was the cause. When the fresh fuel pipe arrives I'll redo all the lengths on the bike and redo the vacuum pipes.

Let's hope this is the last hiccup before I get it back on the road after so many years in a shed.

¡Goal!