Monster 696 Rebuild

[rohan696]

In November 2023, the timing belt tensioners on my 2009 Monster 696 broke, damaging the vertical piston and valves. I have a technical background but knew absolutely nothing about rebuilding engines. People said I should fit another engine or part the bike out, but this bike is my baby and I wanted to bring it back to life.

A year later, in November 2024, I finished the rebuild in my apartment living room and wanted to share some before and after pictures as an anniversary celebration, if you will.

As time allows, I will continue sharing some tips and tricks that I learned during the rebuild that may help others.

A big thank you to Ducati Technical Trainer Jeff from the Bay Area, LA Superbikes, Beverly Hills Ducati, Brad Black aka Brad the Bike Boy, Nellie from DesmoWerx, Krista at California CycleWorks and DesmoAddict on Reddit.

Pictures are visible here- https://www.ducatimonster.org/threads/monster-696-rebuild.362135/

[greenmonster]

Please do share, always interesting.

Ouch, first time I`ve seen, or heard of, belt tensioner totally break!
Any idea why? Who tensioned them last, you or some shop? Using frequency or what method?
How long after last belt change/adjustment did this happen? Remaining roller, was it rusted solid?

[rohan696]

A shop in Florida checked and tensioned the belts last, about three years ago. Dude seemed to know what he was doing and I was just an international student back then who couldn't afford a full Desmo service at a Ducati dealership. The remaining fixed rollers were also pretty rough. I didn't know much about Ducati maintenance to be honest, but this project taught me a lot. Live and learn, I guess!

[ungeheuer]

Just to be clear..... both belt tensioner rollers failed, the vertical AND the horizontal??

(Brad Black, Krista Kelly.... you have some Ducati royalty onboard there mate  ).

[rohan696]

Both of the adjustable ones failed, yes. The stationary ones didn't break but were quite corroded. If I knew back then what I know now about Ducatis, I would've changed them out but it is what it is. Never going to let that happen again, that's for sure!

Oh yes, Brad was kind enough to respond to my emails and his videos were a massive help! Same with Krista's valve adjustment videos.

[ungeheuer]

If they both collapsed, I'm gonna say they were likely set excessively tight against the belts.  Or in terrible shape.  Or both.

[ducpainter]

This belongs in Tech...

Off it goes.

[koko64]

Checking belt roller sets as part of scheduled desmo maintenance does sometimes show a need to replace some or all of them. The owner is advised and has to decide on changing a faulty roller or the set.

It kind of becomes second nature to roll them in your fingers to get a feel of their condition when doing belt servicing.
I don't think the newer set up has the longevity of the older type. That's just my experience.

I remember Brad Black pointed out that Ducati had to review the belt tension specs as they were too tight causing serious issues. That was a considerable time ago.

There's considerable anxiety and opinion about this issue on forums worldwide.

[koko64]

Both of the adjustable ones failed, yes. The stationary ones didn't break but were quite corroded. If I knew back then what I know now about Ducatis, I would've changed them out but it is what it is. Never going to let that happen again, that's for sure!

Oh yes, Brad was kind enough to respond to my emails and his videos were a massive help! Same with Krista's valve adjustment videos.

I bet you learned heaps and now really know your bike well. Well done.

[rohan696]

If they both collapsed, I'm gonna say they were likely set excessively tight against the belts.  Or in terrible shape.  Or both.

Yup, probably both.

[rohan696]

I bet you learned heaps and now really know your bike well. Well done.

Thank you. Absolutely, learned way more than I did in 6 years of college!

[rohan696]

Checking belt roller sets as part of scheduled desmo maintenance does sometimes show a need to replace some or all of them. The owner is advised and has to decide on changing a faulty roller or the set.

It kind of becomes second nature to roll them in your fingers to get a feel of their condition when doing belt servicing.
I don't think the newer set up has the longevity of the older type. That's just my experience.

I remember Brad Black pointed out that Ducati had to review the belt tension specs as they were too tight causing serious issues. That was a considerable time ago.

There's considerable anxiety and opinion about this issue on forums worldwide.

Yup, it's not hard to check the tensioner rollers, best to replace them when they feel rough. I just had no idea about any of this before I took on this massive project. Like Bruce Lee said, "If you want to learn to swim jump into the water."

I remember Brad Black talking about belt tension. Tight belts screech like crazy. 100-110Hz is the ideal frequency if I remember correctly?