What's this sound?

[HPP8140]

The 2002 GS I bought a week ago has a thud sound below 2-3k

There is a thud, then the rpm briefly drops less than 100rpm. Seems sporadic.

Does this sound like cam knock or starter clutch bolts?

Can't believe this!! Now this bike is probably out of commission along with my 95, which this was supposed to replace.

[BockinBboy]

HPP, your issue seems like lean misfire.  I had it on my '04 when everything was stock.

Here is the link to the first thread I originally saw it come up on here, but there have been a couple since. So check that out.

http://gstwins.com/gsboard/index.php?topic=66633.msg801720#msg801720



- Bboy

[Jimbob]

Here is a new video so you can hear it a bit better

http://youtu.be/96Ajlpk36jg

[Jimbob]

So after checking the starter clutch what would be the next thing to check?

[MARider]

The cam chain tensioner is not a hard replacement. You should be able to do it your self with some hand tools. Mine makes a similar noise..I know its my exhaust valves and the cam chain could use a new tensioner. I am not trained in any way to work on motorcycles but after years of owning them and not wanting to pay anyone else to work on them a good ol clymer manual is your best friend..and this wonderful forum.

[Jimbob]

Ok yeah I might do that too. It makes a really loud rattle as I accelerate that is only there for a second or 2 as I'm accelerating and the letting the clutch out then it goes.
I went to find out what I'll get as a trade in today and they will only give me $1000

[MARider]

Yeah gs's are not worth to much. As much as we may love our bikes..or in some cases hate them they are not worth anything. Hell mine has only 7k on it and my tax on registering it was 22 dollars.

[Jimbob]

Yeah I plan to take a week off work to pull it apart. Once I have checked the starter clutch that should I check? I guess I'm after a list to go down as I check things off

[Jimbob]

Any thoughts?

[Jimbob]

I've booked some time off work to fix this up. So what else should I check after checking the starter clutch?

[Jimbob]

Just an update. I checks the valve clearances the left intake was out of spec (tight) so I replaced that shim and now it's in spec. I pulled the left cover off and the main bolt turns with the starter so that looks fine (used Adidas video which showed his bolt did not turn with the fly wheel) what would you check from here?

[Jimbob]

Here is another Video of when cold but it makes a much louder noise when letting the clutch out after a gear change as that is when the revs are low but the engine is under load
http://youtu.be/E5l9jvLhz5w

[gsJack]

Your newest video won't play but looking back to one you posted in late July it sounds more like the loose starter clutch knock.  The Adidas video you referred to was a bike with a loose rotor/starter clutch assembly and he was also showing how to pull the assembly off the tapered end of the crankshaft.  That is a different problem from the loose starter clutch knock I had and that we are talking about here.  The starter clutch knock is heard when the 3 bolts holding the clutch to the back of the rotor come loose and the one large bolt into the end of the crankshaft holding the assembly on can still be very tight as mine was.

When I first pulled the left side cover to check for the starter clutch knock the center bolt and the 3 bolts holding the clutch all seemed to be tight and clutch seemed to function properly so I buttoned it back up and went on to check under the top cover and the right side cover for various possibilities before returning to lhe left side to check again.  With more running time on it the starter clutch was then obviouslt loose when I twisted and turned it some and the center bolt holding the rotor assembly on was still tight.

Are you sure your starter clutch was tight to the backside of the rotor?  It could be necessary to pull the rotor to varify it.

[Jimbob]

It seemed tight but you can't really feel the bolts while it's in place all
3 bolts had the same amount if thread visibly screwed in though so unless all
3 loosened to the same point which I guess is possible.

Would the starter clutch also cause a much louder knocking when letting the clutch out after shifting up a gear?
Is it possible to remove the side cover without draining the oil? Shouldn't 99% of the oil be in the sump?

[Jimbob]

Hopefully working link
http://youtu.be/TaWbgtbska8

[Mrlimb]

I am new and no idea of the noise but the link comes up with a message saying it is private.

[Jimbob]

Should work now

[gsJack]

Here's a pic of mine after I removed the left cover the 2nd time.  Looks like all 3 bolts backed off about the same amount.  I could rotate the clutch back and forth the amount of the clearance of the bolts in the holes and wiggle it a bit too:



I found and others agreed that the starter clutch knock was always heard at idle whether engine was hot or cold and it quit knocking when speeded up to 2-3k rpm, some say 4k.  I could ride about without hearing it at all as long as I kept the revs above 3k rpm and it would come back every time as I slowed below that coming to another stop.  Whether you heard it more or less during shifts would depend on your shifting technique I guess.

I drained the oil completely when I pulled the left and then the right side covers and refilled with fresh oil, I had 2 gallons on hand.  But when I drained the left the 2nd time I saved the fresh oil and put it back in.  No idea how much would be lost if the cover was pulled without draining first.

[gsJack]

Your new vid plays now, sounds like my knocking starter clutch did.

[Jimbob]

So when I was working on yesterday that magnet assembly could move towards or away from me but the big sprocket had some movement towards and away from me should that move?