Which Bearings Have Collapsed Inside My Rev-3 Engine?

[andye]

Hi All

My 2005 Rev-3 started making a noise when running recently.

The noise was most obvious on the overrun, after closing the throttle from medium revs it sounded like a rumbly-grumbly noise, a bit like the engine was full of marbles.

Equally, when riding, vibration could be felt through the pegs.

Naturally I didn't ride the bike after that, although it would start and run - it was just noisy.

Today I pulled the engine out of the bike to have a look.

The piston and barrel are in good shape, and neither of the rings are broken - which is a relief.

However, there are flakes of metal all over the place:

Here are more pictured inside the engine:

More:

There is no evident play in the small end bearing, the piston doesn't rock on the conrod or seem to have any play.

However, the rod does rock, apparently on the crankshaft. Is this normal?

This image (which should be animated) should explain what I mean:

Finally, there's no apparent play when trying to grab hold of the flywheel and move it up and down - no movement at all.

When spinning the engine over by hand, there's an obvious graunching noise.

So - which bearings have failed? I guess it can only be the big end bearing or the main bearings....

Any thoughts?

Cheers.

Andy

Edited August 23, 2010 by AndyE

[stork955]

Gday, Main bearings most likely. Big end possible. Measure side clearance on the rod. Eithewr way, engine split and crank out is coming up.

Cheers,

Stork

[monty_jon]

I don

[betarick]

yep new rod kit and main bearings needed there! split casings and crank will need spliting as well!

[totalshell]

on the plus side .. definately the best illustrated question ever posted.

[andye]

Gday, Main bearings most likely. Big end possible. Measure side clearance on the rod. Eithewr way, engine split and crank out is coming up.

Thanks Stork, how do I measure the side clearance? Is that the clearance between the crank counterweights and the side of the conrod at the big-end end? Presumably a job for a feeler gauge?

I don

Edited August 24, 2010 by AndyE

[boni_tou_1]

If theres no damage or vertiacal play in the Crank (big end) bearing.

I would guess just new main bearings and seals would do you ok

Edited August 25, 2010 by boni_tou_1

[andye]

If theres no damage or vertiacal play in the Crank (big end) bearing.

I would guess just new main bearings would do you uk

Thanks Boni. I couldn't feel any up-and-down play in the conrod, but I'll have a more scientific look tonight.

I need to split the cases anyway to flush all the metal flakes out, so I will order a set of mains and seals, and see if the big end feels rough at all when the crank is in my hand.

Cheers

[lee harris]

on the plus side .. definately the best illustrated question ever posted.

tell me how ya did that....ok its in fotobucket or similar but what did yiou film or store? Its a Gif right???

Lee

[andye]

tell me how ya did that....ok its in fotobucket or similar but what did yiou film or store? Its a Gif right???

Lee

Hi Lee. Yes - most browsers support (and automatically play) animated GIFs. Here's what I did:

1) put camera on a tripod, so it doesn't move

2) take pic 1, rod at maximum left

3) take pic 2, rod at maximum right

4) opened the pictures in Paintbrush to save them as GIFs

5) download and run UnFREEz 2.1, drag both pictures into the window, set a looped animation at 25cs

6) upload to website

That's it! Here's a link to UnFREEz : http://www.whitsoftdev.com/unfreez/

Cheers

Andy

[copemech]

tell me how ya did that....ok its in fotobucket or similar but what did yiou film or store? Its a Gif right???

Lee

No Gif's of you yanking your crank, you naughty!

[boni_tou_1]

Id have a good look around the gear cogs etc to see where the metal flakes may of originated when your there aswell !!!!

But I guess you had thought of that.

[t-shock 250]

How would metal flakes from the gearbox get into the crankcase though?

[boni_tou_1]

A good point

the engine fairies put them in there? possibly ?

Maybe not

[andye]

Ha ha! Thanks Boni, yes, I'm going to check that - I'm hoping(!?) to find a mashed main bearing ball - but my assumption is that it's going to be the clutch side, because the flywheel side sounds smooth (screwdriver test) and there's no play at all at the flywheel side. But I'm prepared to be surprised!

Obviously the gearbox is separate, so let's hope they aren't bits of cog or dog. ;-)

I'll split the cases soon and see what I find. Just need to get hold of a flywheel puller.

Cheers!

Andy