rossoandy broken his bike again!

[rossoandy]

Pete, I b'lieve this is wot's referred to by the Pro's as an "interference" motor. Yes?

 

Andy's been "blessed" by this same thing twice with 2 different RM's. Wot're the probabilities?!

 

Andy -- please don't wander around outside in a lightning storm. . . .

 

Pete, I take it by your previous comments that this is enough of an anomaly, in your opinon, not to go in and "fix wot ain't broke" -- just f'er insurance purposes -- carefully considering the magnitude of "worse case scenario", of course?

ye ratchet I am pretty sure its an 'interference motor' but jus wanted confirmation. thanks.

 

I havent yet pulled the chain and sprockets to see what locates the cam drive sprocket...can't recall from my last one! It may be a pin, yes.

 

Has this failure come up before on V11lemans ?

Surely I not the only one to suffer!!

hmm,wonder if its something to do wiv my err..style of riding!

Still, I not too bothered, it looks like being a relatively easy fix even if I throw a few valves in the equation.

Still wouldnt change the bike....its called character!

[pete roper]

Yuo pull the chain and sprockets as a *unit*, all three of them. The cam sprocket is located, but not driven, by a pin. If the cam nut is loose? Spin it off and behind the washer you'll see the pin. Behind the sprocket is the 'Phonic Wheel' which is the trigger for the crank position sensor, (That's right, being a Guzzi the crank position is measured off the cam ).

 

If the pin is intact then the timing won't of wandered far enough to bend valves. If the pin has sheared you will need to replace it and if you're really unlucky the broken bit will be stuck in the cam so the cam will have to be removed to get it out.

 

Tis is a very, very odd occurence.

 

pete

[rossoandy]

Yuo pull the chain and sprockets as a *unit*, all three of them. The cam sprocket is located, but not driven, by a pin. If the cam nut is loose? Spin it off and behind the washer you'll see the pin. Behind the sprocket is the 'Phonic Wheel' which is the trigger for the crank position sensor, (That's right, being a Guzzi the crank position is measured off the cam ).

 

If the pin is intact then the timing won't of wandered far enough to bend valves. If the pin has sheared you will need to replace it and if you're really unlucky the broken bit will be stuck in the cam so the cam will have to be removed to get it out.

 

Tis is a very, very odd occurence.

 

pete

cheers pete, thanks for info, nut was very loose! I havnt seen the pin yet but have horrible feeling it has sheared...remember the engine stopped..so timing must be a way out. valve or ignition...or both.

Both times its happened after a real fast rev limit bouncing thrash with engine braking down through gears too. I wonder if the nut works loose when engine hits limiter as the crank et will be subjected to abnormal stresses as the ignition cuts in / out. Or is it due to high rpm when changing down/braking through gears..

Both times failure occured at / or a gear or two after a junction. Still think other people must have had same failure..

Oh, can you enlighten me, do heads come off wiv engine in situ?

Manual talks of removing the engine...will make job twice as big if I have too.

And...just confirm valve timing is the two marks adj to one another when crank/cam correctly positioned, forming line through centres of both.

[raz]

cheers pete, thanks for info, nut was very loose! I havnt seen the pin yet but have horrible feeling it has sheared...remember the engine stopped..so timing must be a way out. valve or ignition...or both.

Both times its happened after a real fast rev limit bouncing thrash with engine braking down through gears too. I wonder if the nut works loose when engine hits limiter as the crank et will be subjected to abnormal stresses as the ignition cuts in / out. Or is it due to high rpm when changing down/braking through gears..

Both times failure occured at / or a gear or two after a junction. Still think other people must have had same failure..

Oh, can you enlighten me, do heads come off wiv engine in situ?

Manual talks of removing the engine...will make job twice as big if I have too.

And...just confirm valve timing is the two marks adj to one another when crank/cam correctly positioned, forming line through centres of both.

Not that I have any experience in valve trashing, but I guess you should have noticed a fair amount of noise and possibly felt it too. Or was that the ominous rattle? Maybe the phonic wheel moved enough outwards so the sensor stopped feeding the ECU? I'm not sure if that's possible but if it is that could mean the engine stopped before nasty things happened...

Anyway, the heads (and the barrels and pistons if needed) come off in no time and with engine in place, just follow Petes excellent PDF on engine strip.

[rossoandy]

All stripped out.....took less than two hrs to get heads off and check / rest valve train.

Pin on camshaft was fine, found it laying in timing case!

All four valves have hit the pistons!

oops...

Shall order parts tomorrow from Italia Corsa. Hopefully will rebuild over weekend.

[Guest ratchethack]

Pin on camshaft was fine, found it laying in timing case!

YIKES!

 

Explanation, Please!

[pete roper]

All stripped out.....took less than two hrs to get heads off and check / rest valve train.

Pin on camshaft was fine, found it laying in timing case!

All four valves have hit the pistons!

oops...

Shall order parts tomorrow from Italia Corsa. Hopefully will rebuild over weekend.

 

So you're saying the nut had completely come off the camshaft? and the pin had then worked it's way forward and fallen out of the front of the sprocket after it had ceased to drive the cam? Never heard of shuch a thing? Not even sure it's possible????

 

pete

[slug]

Note to self: Don't let Rossoandy take my bike out for a spin...

[Guest Nogbad]

Note to self: Don't let Rossoandy take my bike out for a spin...

 

Do you think just one bodge point was enough?

[pasotibbs]

Note to self: Don't let Rossoandy take my bike out for a spin...

Shouldn't this be in the ride it like ya stole it thread ?

[motoguzznix]

camshaft nut wasn't tightened......

[jrt]

Shouldn't this be in the ride it like ya stole it thread ?

 

Yeah, I think so.

[Guzzi2Go]

...All four valves have hit the pistons!

Consider yourself lucky! You could have been riding a 1980 Honda CBX 1000. You'd have 24 valves to change now.

[raz]

All stripped out.....took less than two hrs to get heads off and check / rest valve train.

Pin on camshaft was fine, found it laying in timing case!

All four valves have hit the pistons!

oops...

Shall order parts tomorrow from Italia Corsa. Hopefully will rebuild over weekend.

I must say you took this like a man. No complaining, just pragmatic and almost happy Cheers to that!

[rossoandy]

So you're saying the nut had completely come off the camshaft? and the pin had then worked it's way forward and fallen out of the front of the sprocket after it had ceased to drive the cam? Never heard of shuch a thing? Not even sure it's possible????

 

pete

Top marks Pete, I meant to say...pin was'nt sheared off, nut was at end of threads and I pin was laying in bottom af case, pins has to come out to loose valve timing,but only enuff to loose drive through cam and gear.

 

I must say you took this like a man. No complaining, just pragmatic and almost happy Cheers to that!

shit happens and in the scheme of things coulda been loads worse!