I noticed the other day that sometimes when I start the bike up and give it a bump on the throttle, as it's coming back down it makes this kind of "clunking" sound. It sounds a LOT like the engine is suffering from pre-ignition but that definitely isn't what it is. It sounds like it's coming from the counter-shaft side of the motor. Whenever it's done it, it only happens for a few seconds and then stops. It doesn't do it when the motor's cold, and it doesn't do it all the time.

The thing that seems to make it do it is if you let the bike sit for a while, running, idling, while it's warm...and then shut it off and start it back up after about 30 seconds.

I've heard people talk about a funny sound that the older GS's make...something to do with the crank shaft? Mine's a 98, though it's really a 97. Does this sound like that? Or something more serious?

It sounds almost EXACTLY like this: http://www.youtube.com/watch?v=w0UK0A3iHT4

It doesn't sound quite as harsh though...and it'll only do it while coming down from idle...not while actually idling.

Bike/motor only has 11k miles on it.

exhaust leak and valves out of adjustment. check for a rock banging around on a pipe underneath, and motor mounts.

or a magnet has shattered.

or the clutch broke a spring. i'd check the easy stuff first.

That's what my first engine sounded like when the PO let it run low on oil and toasted the crank bearing. Although with an engine, any moving part out of alignment could cause a noise like that, and like ohgood said, check out the easiest stuff first. Are your valves adjusted properly?

Valves should be fine. Previous owner had them adjusted 2k miles ago according to the service records she gave me. I will check for a broken magnet. I was thinking that...but I sure hope not.

It's time to revisit this thread.

I've been experiencing this issue from time to time ever since I first started hearing it.

http://www.youtube.com/watch?v=gbfKrAm_tMw&feature=youtu.be

You can CLEARLY hear the noise I am talking about when I turn the choke off at 21 seconds into the video.

Sometimes it's louder, sometimes it's quieter. Sometimes it happens right when I start the bike, other times it will happen when I shut the bike off after a long ride and then start it back up. Sometimes it happens when I come to a stop.

I am updating because I realized I could faintly hear the sound while riding. In first gear, revving the motor to 6k and holding it, I could hear it. It's faint, but it's there. It isn't as loud as in the video but it's loud enough that I can hear it over the other sounds of the motor. I assume this is bad because from what I understand, the "camshaft noise" goes away when you rev the motor.

The sound seems to be non-linear and does not keep up with the speed of the motor.

Quote from: Kijona on February 18, 2012, 02:46:09 PM
It's time to revisit this thread.

I've been experiencing this issue from time to time ever since I first started hearing it.

http://www.youtube.com/watch?v=gbfKrAm_tMw&feature=youtu.be

You can CLEARLY hear the noise I am talking about when I turn the choke off at 21 seconds into the video.

Sometimes it's louder, sometimes it's quieter. Sometimes it happens right when I start the bike, other times it will happen when I shut the bike off after a long ride and then start it back up. Sometimes it happens when I come to a stop.

I am updating because I realized I could faintly hear the sound while riding. In first gear, revving the motor to 6k and holding it, I could hear it. It's faint, but it's there. It isn't as loud as in the video but it's loud enough that I can hear it over the other sounds of the motor. I assume this is bad because from what I understand, the "camshaft noise" goes away when you rev the motor.

The sound seems to be non-linear and does not keep up with the speed of the motor.

It's hard to tell what you are hearing in the video.  I would take a listen to it close up while idling and see if it sounds like it's coming from the top end or the low end.  Also, you could check if you have lateral play in your camshafts.

Sounds like a normal GS to me. Twins are noisy engines.

I found the starter clutch bolts had started loosening off in two seperate
engines - was an easy fix - have a search for the thread and maybe it will answer your prayers... it did mine!

Quote from: Unsane on February 19, 2012, 03:58:38 AM
I found the starter clutch bolts had started loosening off in two seperate
engines - was an easy fix - have a search for the thread and maybe it will answer your prayers... it did mine!

What exactly is involved...? I haven't ventured that far into the motor yet.

• remove Generator cover
• remove Generator Rotor
• disassemble starter clutch
• replace the 3 bolts and loctite them in
• reassemble the lot and use a new gasket

You should be able to see if the starter clutch is loose just by removing the generator cover