Engine Knocking sound
 

Can someone here help me identify the knocking sound on my friends XT550. He purchased this bike which sounded good but idle was set higher. When he got home and set the idle slower, he noticed this knocking. I know XT's are a bit noisy but this seems pretty intense. Anyone have a good idea if this is abnormal or not?

https://www.youtube.com/watch?v=ujRgqboyuaE

Sound like my one when the bolt for the balancershaft was loose.

I am hoping it is something like that or a clutch problem and not a crankshaft. I would think if the crank rod bearing was out it would knock all the time and not just at idle where is kind of rock and rolls....

Its hard to tell, but it doesnt sound good at all. Is the 550 really that easy to kick, it look like you kickstart a 50..

Engine knock
 

UPDATE:

My friend removed the clutch cover and found the primary gear nut loose. He said that the crank bearing on that side was a bit loose too. He is going to tighten the primary, check everything else for tight and close it up. Rebuild crank etc. this winter he says.

I have to rebuild my 84 this winter due to low compression and who knows what else...

I am thinking about documenting the work with a "good" video. Not a long boring remove every screw video but a highlight, overview and specific points to watch out for. I watched one on youtube and found it to be helpful but missed some important points to watch out for. I hope to do a bit better and be specific. It will be edited by me. Another area of interest for me...

Yes, it did seem a bit too easy to kick so is probably low on compression. My 86 has 170 lbs. compression and even with the compression release, it is a lot to kick over.

Piston slap or maybe a bent valve.
I can't even think to stare mine that way. I have to jump on the lever with most of my weight to get it whirling over. I'd say the knock has to do with why it turns over like that.

I'd like to spend some time having a" talk " with a piece of pipe to those seller that try to cover up an issue just to pawn it off on someone else.:taz: