I was changing the transmision oil on my Beta REV 3 270 (year 2007).

When I took the drainout screw out there was an engine part stock on the magnet which I dont know.

It is 22mm long and about 2mm thick... as you can see it on the picture.

Engine is still working fine.

What is it?

Should I bee worried?

Errr... that looks like your water pump gear pin!!! Are you sure your water pump is still working? Maybe there's another pin in the gear box that looks like that but from what I know its the water pump gear pin! Have you heard any grinding sound lately? I would drain the coolant and open up the water pump cover. Pull on the impeller to see if it comes out or start the bike with the cover off for just a second to see if the impeller spins.

And it could also be the push rod from the clutch. If it is ther is something seriousy wrong

It certainly looks like a clutch pushrod but that would be about 4mm thick?

AirFruit: you were right!

I did exactly as you said and the counter shaft of the water pump (with pump fan) just came off.

How can w.p. gear pin fall out of its position?

Happened in the past to anyone else?

Edited April 2, 200917 yr by kasti

Yeah, it happened to me... except it didn't actually fall off, it just started making crazy plastic gear grinding sound after it slipped half way out.

Good thing you didn't ride the bike around too much or else it would have overheated and maybe locked up.

Look at the back of the impeller? does it look worn? what happened to me was that there were some corrosion happening behind the impeller (the magnesium case) and the rough surface thinned the impeller down. That was enough for the pin to slide out from the gear on the other side. If you open it up and see how it's put together you'll see what I mean! It is hard to describe. I tried to put a spacer in there at first but that made it worse.

My left case was replaced under warranty though...

Edited April 3, 200917 yr by AirFruit

Just another thing:

from which material is water pump gear (sprocket) made of? Plastic?

regards

To be basic, yeah, its a whitish plastic.

What's up? Don't tell me you found some white plastic bits in your engine oil...

To be basic, yeah, its a whitish plastic.

What's up? Don't tell me you found some white plastic bits in your engine oil...

I still havent unscrew off the internal clutch cover.

If I pull out the wp counter shaft, should be the water pump gear seen through the hole (through barrings)?

well, the gear is held on by the shaft. It might have moved after you pull out the shaft but its suppose to be right behind the seal+bearing

Today I took it apart.

Looks like the gear in some strange way managed to fall of the shaft. After I saw the way the gear is fixed on to the shaft (with gear pin) I dont have a clue how that happened.

The gear was laying on the bottom of the cranckase - unharmed; lik a new one! I have put it back together, and now the pump is working just fine.

Maybe the previous owner (some spanish guy) did some work around water pump and didn't put it back together in a proper way!?

Once again... thanks again for the hints AirFrut.

One more question:

is there on the market some good but cheap replacement for the original Beta REV 3 skidplate?

Original is 77

Edited April 5, 200917 yr by kasti

Another possibility is that wear on the rear surface of the pump impeller caused by a slightly rough casing has generated enough end float (movement in and out) on the pump shaft to allow the pin to slide out. I have known one that when just re-assembled did indeed find its way back out.

Just like I mentioned before and as M&S did, my problem was due to the back of the propeller wearing down Just be very careful when riding it!!! Did you check the back of the impeller!?!?

I put mine back the first time without knowing the cause. It was fine for a while but due to my love to hop, it popped out real quick again. If you hear any slight abnormal ticking or grinding noise... you should check it again. If it does pop out again, time to get a new impeller. But did you also see if your magnesium case is okay? is there corrosion behind the impeller or just the surface is rough?

Edited April 7, 200917 yr by AirFruit

Is there any trick to check water pump working beside taking off the pump cover?

Listen for any abnormal sound coming from the water pump. If the gear comes off you can usually hear a ticking noise and if you put your hand on the water pump cover you can feel the vibration too... that's about it? or your bike overheating and losing power haha