Noisy fuel pump

[carloalberto85]

Hi all,
I'm new to the forum and new to the FZ6. I just bought one used from 2004 some days ago and I am getting accustomed to it.

Question to you:
When I am driving I can here some kind of constant whistle like a Larsen effect.
I went to a Yamaha dealer and they listened to the motorbike sound and they said it is the fuel pump and that this noise is quite normal.

It is true? Do you here this whistle too?

Thanks
Carlo

 

[TownsendsFJR1300]

Welcome to the forum!!!

Re the noise, mine does NOT have it, most don't and NO its NOT normal. The noise you hear when you turn the key on initially, (the pump priming up) is as loud as it should be..

Its generally a sign of it failing however others have ran their pump, with wierd noises for years. Fuel in the tank helps keep the pump motor cool so NOT running it close to bone dry would help.

A bike that sat for awhile not full tends to have the inside of the tank rust. That rust will get into the pump filter (not replaceable), somewhat cleanable (on the outside at least).

Are you sure its the fuel pump? If you open the tank cap, can you hear it better? You could have vacuum line off, etc.

Here's a recent video from a member here, you can't even hear the pump prime its so quiet (he has COLD revving issues);
https://docs.google.com/file/d/0B2-VbUcK-W_EQS16SEFiZTBtU2c/edit?pli=1

If its under warranty from a dealer, I'd push for a new pump or have him extend the warranty for just the pump. He's going to drag his feet as new pumps are NOT cheap.

Can post a vidio like the one above where we can hear the sound? Just to see if it is the pump or something else. Again, with the gas cap open , with maybe a half full tank (or less) should be noisier and easier to hear..

 

[payneib]

My bike whistles, it's just intake noise, gets alot louder with a new air filter. I'd check with the fuel cap open like the legend above says before deciding what it is.

 

[FinalImpact]

Perhaps it depends on ones hearing? Although faint, i can hear the pump running at idle. I can also hear the tone changes from the RR doing work like when the blinkers are on. Its very faint but present.

If it is a rust ball inside, that needs attention and with the assembly pulled, the electric motor section of the pump can be removed and replaced. The motor/pump roughly $40 - $60 depending quality.

The pump assembly just clicks together. Key word is Denso, Yamaha, Honda, Ducati, and others all use this pump assembly.

 

[ozgurakman]

If you can hear the fuel pump, maybe your helmet's sound isolation is pretty bad or you're running the bike with too low fuel. You can hear the fuel pump's noise before starting bike, just after turning ignition on. if sound is similar with when running, don't panic and enjoy the ride.

Welcome to forum, BTW.

 

[carloalberto85]

HI,
I opened the fuel tank cap and I could hear the noise coming definitely from the pump. I am not under warranty,I bought it from a private person but I went to yamaha dealers and they told me that it is not a very big problem. Until the pump does not brake it is not worth to change.

Meanwhile, can you help me with some links on where to buy a new pump(or pump group) for my FZ6 RJ07? Sorry but into the pump group there is not the filter too?

 

[carloalberto85]

Something like this will fit in your opinion?

Yamaha Direct Fit Fuel Pump 1994 2015 FZ YZF R1 R6 Stratoliner V Road Star New | eBay

This is only the fuel pump...it is ok to buy only this or should I buy also the rest?

 

[TownsendsFJR1300]

Something like this will fit in your opinion?

Yamaha Direct Fit Fuel Pump 1994 2015 FZ YZF R1 R6 Stratoliner V Road Star New | eBay

This is only the fuel pump...it is ok to buy only this or should I buy also the rest?

You really have to take the assembly apart to see how good or bad the filter inside is. The plastic parts will be fine (I'm not positive of the motor itself part #). The filter is non servicable (short of blowing, cleaning) the outside of the filter.

Below pic's are of the dirty filter, the other, with the arrows, will pop the fuel gauge assembly off in the tank making removal MUCH EASIER. Re-assembly, you can install all assembled as one unit.

 

[carloalberto85]

Ok I will decide what to do....in any case I can buy only the fuel pump itself(ebay link), I don't need anything else, right? For now I don't think I will disassemble anything.

The motorbike is working fine...
What could be the worst thing happening caused by an old/noisy fuel pump?

 

[FinalImpact]

The pump has two sections, the electric motor and the rotor & housing which has pretty close tolerances so the pump can build pressure.

The motor could be loud for whatever reason and run a long life or die. Who knows....

The pump if too loose with its internal clearance will loose pressure. Pressure loss throws the fuel injection map out the window and could result in hard starts or inability to rev out because it lacks fuel pressure and runs lean and hot. << a bad combination.

Number one cause of noise is likely a restricted strainer. Depending on how bad it is, debris hinders fuel flow and the pump cavitates which wears out as the impeller is litterally boiling the gas.

My vote would be to take it apart and look. Backflush the strainer repeatedly until clean.

Hint, test it in a pan as is using water or diesel fuel. Clean it and repeat. If you remove a bunch of sediment, it may be a lot quieter once the restriction is removed. You will need some hose, test leads good for 4Amps, and if you have a pressure gauge or can rent one, look for 36psi.

The point of before/after testing is to compare tones and make sure you have no leaks.

 

[FinalImpact]

Also, take a look at this;
FUEL TANK, FUEL PUMP, AND FUEL GAUGE

It may offer some help in your investigation.