Belt tensioner pulleys

[chipripper]

Sorry if this question has been asked and answered. I got to the belt change / valve adjust part of my 12000 mi maintenance session, and noticed my vertical cylinder tensioner pulley free-wheels maybe half a turn when I spin it with my finger. The other three spin smoothly, but stop spinning when I stop pushing them. My notes from the 6000 mile valve check said all 4 rolled smooth but did not free-wheel.

I searched and read several threads, about stuck pulleys, notably this one ->http://www.ducatimonsterforum.org/index.php?topic=3175.0 where Duckpainter said his do not free-wheel.

How do I know if a bearing has gone bad or is going bad? Should I replace it anyway just to be safe?

Now that I look at the photo, I notice grease around the inside of the suspect pulley, and the other 3 look dry. Maybe the bearing has lost its seal and its grease.

[Howie]

I would change it.

[Speeddog]

+1.

[chipripper]

Thanks for the responses guys.

Ouch! That pic looks like it could have been real bad for the valves.

I will pull it off the bike in the morning and give it a better look. Is it serviceable with new bearings or do I buy a new tensioner assembly? I saw a thread with a bearing part number but it was only compatible with bikes through 2006. Advice?

[chipripper]

So I removed the tensioner this morning and I don't see any c clips or any other method of disassembling the roller. It looks like one large bearing press fit onto the roller. It definitely has some play when wiggled, and sounds a little crunchy/dry when spun. GP has one in stock for 96$. I will probably get a new one and see if I can re-bearing this one as a spare.

Does anyone know where to get one at less than dealer price?

Has anyone replaced the bearing in this specific roller?

[Speeddog]

If it spins freely and makes noise, it's toast.

The three companions to the one blown-up roller I showed above were noisy and free spinning.
Owner was not happy about the replacement cost, but he did understand that he dodged a large-caliber bullet and he'd best not press his luck any further.

AFAIK, not a serviceable component, unfortunately.
Folks have searched and not found.

[chipripper]

Thanks Speeddog. Headed to GP now, to give them all my beer money. I will definitely reduce the interval for checking the rollers. I am very happy I decided to take my bike apart instead of riding. It is tough to do, since there is no "winter maintenance season" in San Diego. 

[EEL]

The most common reason for busted pulleys is improper tension. Mainly too much. Keep it at around 100 Hz for both belts.