Why did the Suzuki DR650 R engine fail?

In this video, we're trying to find the reason why the engine failed on this 1991 Suzuki DR650 R

What did we find?
After disassembling the engine we found that the timing had jumped and the exhaust valves had touched the top of the piston, which resulted in a bent piston pin and failed crank rod bearing.
Looking at the history of the bike, it has done only 20,000 km in its life. Since 2004 the bike has done only 1300 km, so it has been sitting for a while.
This time has resulted in dry rotted timing chain guides, that have turned from hard rubber to brittle plastic. Since the old cracked guides can't provide the necessary timing chain tension, the timing chain jumped and resulted in an engine failure

Check out the channel updates on:
Instagram:   / restorationvalve  
Tiktok:   / restoration_valve  

Check out the eBay store for the spare parts from the projects: https://www.ebay.com/usr/restoration_...