Kawasaki FS691V

[Malcolm B]

Pulling my last it of hair out.
I have a Kawasaki FS691V fitted within an ATCO GTX48HR

Checked all fuels lines filters etc.
When by passing new fuel pump and running the mower down hill (gravity fed) engine starts and runs perfectly.
Check impulse line and no wear and tear and no visible leaks.
Blown into impulse line and clear.
Have some suction on impulse line but strong pulse.
When all connected as normal no fuel being fuel through.
Any suggestions as to where to look next?

[Mick]

Hi Malcolm, and welcome to TGMF.

Did you say it was a new fuel pump?

[Malcolm B]

Hi yes new fuel pump and filter.

[Mick]

Hi yes new fuel pump and filter.

Thanks.  Was it a genuine Kawasaki fuel pump, or a generic one as found on amazon etc?

You should be able to pull the hose from the pump which leads to the carburettor, and then using a suitable container turn the engine over and see if it's pumping any fuel.

[Malcolm B]

Hi Mick tried all tests.
New and old fuel pump not pulling fuel through the line.

If I bypass the fuel pump and gravity feed (Jack the mower up at the back) fuel flows and the engine starts and runs.

What is the chance of 2 faulty fuel pumps?

[Mick]

Does seem strange that they have both stopped working, it is always possible that you've been unlucky. 

Have you actually removed the impulse hose to check it hasn't collapsed inside, or got a blockage?  Oil filer cap is good etc as it relies on pulse from the crankcase.

[Malcolm B]

Hi Mick, yes removed impulse hose and all good.

Also when impulse hose connected I can blow through the tube and feel the air  at the dip stick tube with the cal removed.

All caps on tight.

[Mick]

Hi Mick, yes removed impulse hose and all good.

Also when impulse hose connected I can blow through the tube and feel the air  at the dip stick tube with the cal removed.

All caps on tight.

It's starting to look more and more like the pump then to be honest. If fuel flows from tank to pump, and pulse hose is good.   

[Malcolm B]

I will get another pump tomorrow 🤞

[Malcolm B]

Hi tried another pump. Still not flowing.
Checked all lines again and good flow from tank to pump (pump disconnected)
Cannot get flow through 3rd.2nd or 1st pump.
Will change all lines incase of pin hole somewhere BUT no fuel leakage.
Will change impulse line as well.

[Mick]

Hi tried another pump. Still not flowing.
Checked all lines again and good flow from tank to pump (pump disconnected)
Cannot get flow through 3rd.2nd or 1st pump.
Will change all lines incase of pin hole somewhere BUT no fuel leakage.
Will change impulse line as well.

Very strange, I did say to check the impulse hose which you already said was ok.  It's got to be blocked somewhere, either the pulse hose itself has collapsed inside, or where it attaches is blocked in some way. Either that or you have a massive air leak from the crankcase or valve covers, but then I'd expect oil everywhere.  Also check that the fuel hose from tank to pump isn't collapsing when the pump sucks on it, it might flow with gravity but when pulled through. The hoses are made up of layers, like a hose liner within a outer sleeve.

You could always just to test this theory connect a suitable container of duel to the pump with a length of good hose directly to the pump and try it.

I hope you track it down, I'm also curious to know what's going on with it.