Engine knocking shortly after starting (3en1)

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graeme
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Bike owned: VT250FG, FZR400 EXUP
Location: Durban, South Africa
Engine knocking shortly after starting (3en1)

Post by graeme »

After getting her up to around 160kph for the first time it now seems like the knocking noise (that was already present) has become more pronounced - clearly audible at idle. It seems to come from low down in the block and is most audible from directly under the oil pan. My first thought was big-ends... :( but a mate suggested it could be due to oil starvation, possible a blocked oil passage / oil filter?? Hell maybe even the oil pump...

What lends his theory some credence (I think) is that if the bike has been sitting for a while, the knock only starts a couple of seconds (um... 4?) after starting. Kinda like oil is settling somewhere, but then is not getting back there after the engine starts. The noise may also *possibly* be coming from where I think the oil pump is... but I need to check this.

The oil level looks fine going by the window.

I can feel the knock through the chassis... but haven't been able to clearly identify the source with the 'stethoscope' method.

Any ideas?
Evilchicken0
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Re: Engine knocking shortly after starting (3en1)

Post by Evilchicken0 »

It sounds like one of those jobs that should be done sooner rather than later.
graeme
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Bike owned: VT250FG, FZR400 EXUP
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Re: Engine knocking shortly after starting (3en1)

Post by graeme »

Heh heh, yeah... she's just sitting in the garage for now :(
Evilchicken0
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Re: Engine knocking shortly after starting (3en1)

Post by Evilchicken0 »

have a look arounf for a 600 3HE engine just in case ;)
Morespeedvicar
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Re: Engine knocking shortly after starting (3en1)

Post by Morespeedvicar »

Hi,
you sure its not the exup rattling around in the exhaust? Your good trundle may of cleared the soot out from around the bearings. Maybe worth a look before you start taking the engine out!
Cheers
Ian
graeme
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Posts: 30
Joined: Thu Jun 09, 2011 7:10 pm
Bike owned: VT250FG, FZR400 EXUP
Location: Durban, South Africa
Re: Engine knocking shortly after starting (3en1)

Post by graeme »

Thanks but nah it's not the EXUP, I've just given it a make-over... the noise is coming from inside the crankcase.
graeme
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Bike owned: VT250FG, FZR400 EXUP
Location: Durban, South Africa
Re: Engine knocking shortly after starting (3en1)

Post by graeme »

This morning I also checked if the noise changed when the clutch is in or when she's in gear. Also checked if it changes when there's a bit of load on the motor (i.e. in 1st gear and released clutch enough for it to bite a bit)... didn't hear any change.
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CMSMJ1
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Re: Engine knocking shortly after starting (3en1)

Post by CMSMJ1 »

Sounds like the engine is going to die to be honest. Have you checked the oil - drop it out and see if there are any metallic flecks in it?
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graeme
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Bike owned: VT250FG, FZR400 EXUP
Location: Durban, South Africa
Re: Engine knocking shortly after starting (3en1)

Post by graeme »

oh my word... Morespeedvicar I owe you a beer or 2, I guess I'd convinced myself it had to be something bad ;)

I totally dismissed your suggestion about the EXUP... but it just sat there at the back of mind... I just checked and it is the farking EXUP valve. Some play has built up in the cables and it's just rattling away in there, I can hardly believe it... it is SUCH a regular sound you'd swear it was something attached to the crank...

:D
Evilchicken0
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Re: Engine knocking shortly after starting (3en1)

Post by Evilchicken0 »

That's cool - I bet your a happy man now :grin:

Remember adjust the cables to be finger tight only.

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