Ducati timing belt issue

[Corporal Punishment]

I know it's a bit off topic for here but I was wondering if anyone has any insight into fitting Ducati timing belts.
Long story short, I replaced my timing belts, first time doing this, so I watched the youtoob vids, did my research and took my time.
Double marked everything and I'm pretty sure I got it right. The rear cylinder inlet cam put up a bit of a fight but I got it on eventually
Note at this point - The cam holding tool you can buy on the net is useless and doesn't fit without serious alterations.
Anyhoo....Belts fitted and at loose tension, I started rotating the motor by hand to check for any binding or nasty crunching sounds.
It turned over nice and smooth.....but....there is a strange moaning sound when the rear cylinder is on compression.
My question is this...is this just a new stiff belt issue, or is the piston forcing it's way "past" the valve. I don't think so but I'd like to get someone else's opinion before I fire it up and possibly do serious damage.

 

[DrFarkoff]

Have you got a sparkplug out off the rear cylinder while you are turning it over??

If not take one out and try again ??

 

[Shunt]

I did a belt change on one of these the other year. I'm not a lot of help. But. Are them funny valve clearances ok too?

 

[Corporal Punishment]

Ya, both plugs out. Valve clearances should be within spec. I had my daughter listen to it while I turned the engine. She reckons the noise is coming from the exhaust cam area. Anyone know if a skipped tooth would cause a total lockup as the engine is turning quite freely.

 

[(RIP) Bin Ridin]

Valve spring vibe - I hear this on airhead when turning by hand. Can you put you finger on the springs? It is not desmo is it?

 

[Corporal Punishment]

Valve spring vibe - I hear this on airhead when turning by hand. Can you put you finger on the springs? It is not desmo is it?

Monster S4 916. Desmo yeah.

 

[(RIP) Bin Ridin]

I don't think you could force a piston past a valve by hand. Can you put a finger on the valves while turning / moaning so to speak? Might feel the vibe.

 

[Corporal Punishment]

I don't think you could force a piston past a valve by hand. Can you put a finger on the valves while turning / moaning so to speak? Might feel the vibe.

Your right. The valve is pushed down by the cam lobe so hand pressure shouldn't be enough to cause the piston to push back enough to ease the piston past the top of it's stroke.
I've just been out again and turned the motor with the starter and all seems well. I'll start it for real tomorrow when I'm happy with the belt tension.
Thanks all for the help.

 

[Keith Chapman]

Spark plugs out, turn the engine over by hand and make sure all the timing marks line up. If a cam has moved slightly while fitting the belt take the belt off and re-align the cam by hand, refit the belt and check all is OK by turning the engine over by hand.

 

[Corporal Punishment]

Spark plugs out, turn the engine over by hand and make sure all the timing marks line up. If a cam has moved slightly while fitting the belt take the belt off and re-align the cam by hand, refit the belt and check all is OK by turning the engine over by hand.

Thanks Keith, I did this yesterday and with the crankshaft cog pointing at it's timing mark, all 4 cam cogs are pointing at theirs. For some reason, the teeth on the belt that I marked to make sure I didn't skip a tooth don't line up anymore but this was explained on one of the ducati forums - something to do with belt stretch I think, but the cams line up.

 

[Bendy toy]

Cams and crank linng up is what matters anything else is the system compensating for belt stretch etc.


Sent from a widget that can't spell.

 

[Corporal Punishment]

Cams and crank linng up is what matters anything else is the system compensating for belt stretch etc.


Sent from a widget that can't spell.

Alls well that ends well. Biked fired up and running fine. Phew. Thanks for all the pointers and advise.

 

[Bendy toy]

It's a scary job on any engine never mind a Ducati with a rubbish cam lock.

Respect


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