One of the biggest problems on the diesel though is chain stretch which throws the timing off enough to kill the power output and fuel economy.
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And that is reason enough to make the change. They sell off-set cam keys for this,
but the easy and best solution is a new chain. You can buy a repacement w.master link that , hooked to the old chain, threads
through the gears with ease. I use a bungee cord to keep tension on the chain and turn the crank by hand in the running direction.
Any that have done this will tell you it is not a big expensive job. It is also advisable to check the chain tensioner.