damaged balancer chain sprocket in KLR 650 engine

Damaged balancer chain sprocket on the crankshaft of my KLR 650 Motorbike.

The damage to the balancer chain sprocket was most likely caused by a loose balancer chain, which was caused by the failure of the balancer chain tensioner system (I found that both the "doohickey" and the tensioner spring were broken, which is a common failure in the KLR 650 engines).­

The bad news is that replacing this sprocket (a part that costs less than $40) involves taking the engine off the bike and splitting the case open (i.­e.­ basically taking the entire engine apart).­ That's a 20 hours job at least.­

By comparison, changing a valve is a breather.­

Even worse: on the newer KLR 650 models (post '97, i think), this sprocket is integral part of the crankshaft, and it cannot even be ordered as a spare part.­

All this work to change a small sprocket! What did the Kawasaki engineers think about when they designed it? it would have been simple to design it so that this sprocket could be replaced easily!

close-up crankshaft damaged sprocket doohickey kawasaki KLR 650 macro mechanic motorbike motorcycle engine sprocket teeth worn sprocket

Photos that are currently not in any other album.­