What's this sound?

[Jimbob]

So the bike has been making a strange noise which i have been trying to record, someone described it as tiny when it was cold, which is the first video the second is when its warm. Any ideas?

http://youtu.be/kI4_kxAosaQ

http://youtu.be/5wtsHJ1dCcw

[cWj]

I don't know what it is, but Pokey does it, too.

Tappets?

[Nocluejoe]

Kind of a guess but I think it sounds like a bent valve or piston when's the last time you checked your valve clearance?

[gsJack]

That second vid warm sounds like normal GS running noises except for the light valve tappet noise in the background.  If those are exhaust valve noises that's good, they need more clearance for long life.

The knock in the first vid cold sounds like piston slap confirmed by it being gone when warm.  Is that a high mileage engine?  It still sounds better warm than my 100k mile 02 does.     Gotta get some 20-50 back in mine for this warm weather.

A compression check will indicate if it's a bent valve mentioned above.

Just my opinions, my ears are getting old.

[Jimbob]

The bike has 55k km's on it. I checked the valve clearances the other day because of this noise. They were LI: 0.4 RI: 0.5 LE: 0.6 RE: 0.7

[Jimbob]

Any thoughts?

[Jimbob]

Went to mechanic yesterday and he said it's the cam chain so I need  to replace the cam chain tensioner. So next question would you guys use a manual or auto tensioner?

[HPP8140]

Sounds like mine, but hope it's not as bad. The rear cam-chain guide broke in half.

[Jimbob]

Was that an expensive repair?

[Blairbee]

does it sound like it is coming from left side of motor near crank? magnito coming loose starter gear on crank? does the sound exist from idle to about 2400 rpm? youtube starter clutch and or starter clutch loose bolts........ been down this road not fun

[Jimbob]

according to this video https://www.youtube.com/watch?v=GxS5yZ44AHU
if the bolts were lose it would not start and would make a whiring noise

[HPP8140]

Was that an expensive repair?

well, I was told it would require splitting the case, so decided not to fix. The cam-chain rattled at low revs because of decreased tension due to no guide to push against the chain. The tensioner was rubbing on the chain instead.

[Blairbee]

before it got to the point of would not start and whiring noise bike would start a bunch of times .....was stranded at work bump started to get haome then and to ride to mechcanic 3 bolts that hold starter gear on magnito one was loose other two were broken had to replace starter gear, bolts gaskets apox $250 in parts and the same in labour these prices are canadain i'm sure if your in the U.S. it would be about half seems to be the way it goes up here 

[Jimbob]

Hmmm cause it's starts fine everytime.
I think I'll buy the cam chain tensioner and take it to the mechanic do you guys use a manual or just the auto tensioner?

[Jimbob]

So took it to 2 mechanic today because the knocking sound  I noticed is loud if you accelerating so if you stopped starting to let go of the clutch doing about 2500 rpm's you can hear it loud.
1 mechanic said he has never heard of a GS500 making the noise and would need to pull it apart and the other said they would need to pull it apart as well.

So the problem I have now... Is it worth doing? If it's going to costs a thousand or more it might be cheaper to put a new engine in.
What do you guys thing?
Would it help if I made a video of it doing the sound when doing what I said above?

[gsJack]

I see you posted your bike has about 55k km's (only about 35k miles) on it after I posted above, I wouldn't have thought it a piston knock with such low mileage.  A piston knock which would usually go away as the engine warmed sounds much like the starter clutch knock Blairbee had and that I also had this spring.  The more I listen to the knock in your first video in your first post the more it sounds like the starter clutch knock but it doesn't knock like that in the second video.

The loose starter clutch knocks hot or cold at idle up to 2-3k rpm, some say 4k. If your gettng that knock both hot and cold I wouldn't be considering a big costly engine tear down or replacement without first pulling the lower left engine cover where the generator rotor is and checking for a loose starter clutch which is bolted to the backside of the rotor. It cost me about $20 to fix mine not counting the free labor I supplied or the 3 oil changes I made while removing the left then right and then left again lower covers while checking it out.

[Jimbob]

Ok thanks I'll see if I can record the sound while the bike is warm on Tuesday

[Jimbob]

So when I pop the left side cover off what stuff should I check?

[bombsquad83]

Ahhh the starter clutch...it's the new goats!

[Jimbob]

Anything other than starter clutch while I'm in there?