Problem after fuel filter change.

[Paule230]

The other day I replaced my gear box and diff' oil(75w/90) and the engine oil (20/50). I also replaced the fuel filter with a branded Mahle KL145 one.

I had no issues afterwards when I went for a 50 mile ride straight afterwards.
Today the bike started fine then after a few minutes it wouldnt rev and gave the symptoms of low fuel (tank is half full).
After a minute or so it cleared up and ran fine for about 10 miles then briefly felt hesitant again as I was cruising at around 50mph. This happened once more just before reaching my destination which in total is about a 18 mile ride.

Inbetween the episodes of feeling hesitant the bike run perfect.

I have checked the filter and the arrow is pointing towards the front of the bike and the short rubber hose which you detach to remove the filter from the tank.

The long rubber hose is attached securely to the rear and this hose loops up and over the filter.

Could I have a air lock or something else. Prior to touching the filter I hadnt had any issues, The hoses appear in good condition and are all secured.
The fuel in the tank is Shell V power so its a good quality fuel.

Thanks in advance.

[Motorhobo]

How old is the fuel pump? Maybe you're getting lucky and it's giving you a warning rather than just failing outright.

Alternatives to OEM fuel pump are in the Lieberry.

[Paule230]

Thats a thought, is there anyway to test the fuel pump or is it just a case of it work or it doesnt?

[K75RT Keith]

No chance of an air lock as the pump pressurizes the fuel system
Did you check the hoses in the tank for cracking or splits? 
Was there any gunk in the bottom of the tank? 
Did you also replace the sock filter on the bottom of the pump?   
Check that the connector for the fuel pump and sending unit is tight.  You may need to spread the male ends a little to ensure good contact.

[Paule230]

I have taken the filter back out to re check everything, it is all connected correctly, the rubber pipes appear sound but I did notice the pump wasn't clicked fully home by the 2 plastic tabs.

So I removed the pump to check the rubber gasket underneath, this also proved to be in good condition and have made sure the pump is pushed down properly so that the plastic lugs are in place locking the pump in situ.

Could the fact the pump wasn't fully secure have caused the problem?

I have also replaced the plugs today which I had planned to do anyway as they don't look like they've been changed for a long while. The ones in the bike were Bosch XR7LDC, I have now fitted Bosch XR5DC

Hopefully the loose fuel pump caused the problem and along with some nice plugs and the fact I have the throttle bodies being balanced tomorrow will give me a nice smooth bike ready for my trip to France next week.

[rbm]

I have checked the filter and the arrow is pointing towards the front of the bike and the short rubber hose which you detach to remove the filter from the tank.

  Isn't it supposed to be the other way?

[Paule230]

I hope not, I looked it up on youtube.

[Inge K.]

Your fuel filter is correct mounted, the arrow indicates the direction of flow.
From the fuel pump the hose goes to the rear of the tank, makes a 180^oturn and enters the rear end of the fuel filter.

[Paule230]

Your fuel filter is correct mounted, the arrow indicates the direction of flow.
From the fuel pump the hose goes to the rear of the tank, makes a 180^oturn and enters the rear end of the fuel filter.

Thanks 😃

[johnny]

this motobricker is calling it a dirty under tank electrical connector...

j o

[drut]

this motobricker is calling it a dirty under tank electrical connector...

j o

Good point,symptoms would point towards electrical/dirty connection rather than filter issue.As a matter of interest I replaced my fuel filter with a Mahle KL 145 a few months ago with no issue,a fuel pressure/flow test would check things out but as above it is likely something you have disturbed rather than the filter itself.A location in your profile might place you near a motobricker able to help.

[Paule230]

I rode the bike home from work after I clicked the pump properly in place and it rode without fault for the 18 mile journey. I'm thinking the pump was never in situ properly and when I changed the filter I caused the pump to sit even higher so it was only just under the petrol level. Could this have been the problem?
Bikes now at my local mechanic now having the throttle bodies balanced so I have asked him just check it over.

[drut]

"I rode the bike home from work after I clicked the pump properly in place and it rode without fault for the 18 mile journey. I'm thinking the pump was never in situ properly and when I changed the filter I caused the pump to sit even higher so it was only just under the petrol level. Could this have been the problem?"

Sounds credible,a few more rides will tell!Amazing how disturbing things gives unforeseen consequences!

[Paule230]

Hopefully we have got to the bottom of it. It looks like one of the original metal HT caps has been shorting out against the head. Which was causing the bike to randomly run on 3 cylinders. The cap nearest the rear was sooty and covered in pitting.
On top of this the rubber vacuum take off caps were perished causing a air leak on one of the throttle bodies. .

Time will tell but so far I've ridden for over 50 miles and up to 130mph without issue.

[pdg]

I've ridden for over 50 miles and up to 130mph without issue.

Should I assume that speed was attained on a private road / racetrack / in Germany? ;)

[Paule230]

I've ridden for over 50 miles and up to 130mph without issue.

Should I assume that speed was attained on a private road / racetrack / in Germany? ;)

My work use a very large piece of land.