XT600E '99 engine knock
 

Hello everyone,

I own an XT600e which has a case of engine knocking, it all started a couple of weeks ago when i was cruising doing +-100/110km/hr when suddenly i experienced something what felt like a loss of power, i quickly took the first exit i could and stopped to check my motorcycle which was now making a knocking sound. After this i havent ridden it because i was afraid i would cause more damage.
The bike still starts and drives but the knocking/metallic sound worries me.

Here's a video of it.

https://youtu.be/i5koUh6Mt18

The bike has about 60k kilometers on it.
Could this be the infamous loose primary gear nut?

mmm.... doesnt sound good and im afraid it is not just the balancer nut. well, at least thats an easy thing to check, just remove the right side engine cover and see....
if all is ok there, then its top end off...my money is on something related to the valves, but hard to tell until you open

Do the easy stuff first. Check your valve clearances. If youre lucky one of the rocker adjuster nuts has come loose. If youre unlucky the conrod small end has chewed out and will require crankcase split and crank rebuild. Was your oil level ok?

XT600E '99 engine knock
 

Hi Liam,
The loss of power is consistent with partial piston seizure, and the noise sounds like piston slap. I'm sure you would have checked the oil level, but these engines have a history of oil pump failure and piston damage. Especially if your bike has the 'empty oil tank in the morning' syndrome,
Just a thought.
Be well,
p

Nothing to do but strip it down ...

Decided to give up on trying to find the cause and rather replace this 64000km old engine with a fresher one instead, didnt want to open it up to find out a boatload of things might need to be replaced which would end up being rather expensive as there arent alot of spareparts to find where i live.