What Blueknyt said, right on target.  I've had that clunk in at least 2 of my bikes in the past including the 97 GS.  Been awhile since I've heard it.

The little springs in a sprag clutch don't really take any load, they just hold the rollers in place till the wedge action grabs the rollers when the starter motor engages.  When the engine starts it speeds away from the starter motor allowing it to freewheel til you release the starter button.

A lighter oil could possibly get rid of the noise. I've only had it in cold weather.  I seem to remember you were using some straight 40 weight  oil or something like that due to oil consumption.  Probably get rid of the noise with some good 10W-40 oil, but then you'd probably quickly get rid of the oil too.   :lol:  :lol:  :lol: Anyway, I quit worring about that noise like the the other infamous noise in the top of the GS engine that many have heard at idle on a hot GS.  I wouldn't fret about either noise too long.  

I have 1 qt 20/50 in it with 2 qts Lucas oil stabiliser... That thing is like paste... So OK it could be the reason. I will switch to thinner oil and see... Yea its very thick and very cold... Would spinning the rear wheel before starting help... or something else like that.
Cool.
Srinath.

The GS doesn't have a sprag type starter clutch. It has 3 cylinders that are spring loaded on ramps that bear against the crankshaft. It is on the left side of the engine, behind the alternator rotor.

Some sealed lead acid batteries can't supply the peak current that a liquid lead-acid battery can. It could be that when the starter needs a lot of current to turn past TDC, the sealed battery doesn't have the current capability. A second later, the compression has leaked down some, and the starter windings cooled some, and it kicks past TDC.

I would try a normal battery, and maybe a different starter. The bearings in the starters can start to drag, or you get shorts in the windings from over-heating that increase the current draw, and decrease the torque.

The 2 battery I have had this issue with was one of those black walmart ones. The one I had before was a stock grey one that comes in the Yamaha R1's... valve regulated lead acid battery... It just wanted to stop cranking over... This one must have more punch than that cos it cranks right past the clunk... Ok I'll try a regular battery... this bike will fit any battery... including a lawnmower battery...
Could the starter have wear on its gear teeth... making it get more play... and then clunks when it re engages ..
Cool.
Srinath.

I doubt it. Unlike car solinoid starters, the GS's starter gear stays permanently meshed with the other gears of the reduction train. The only area of weakness is the starter clutch. If the little bearing springs go, then it might slip like you mentioned, but I think it would do it consistantly...

If you really want to find out about the starter. Its fairly easy to remove. You don't have to take off the side cover, and only take a little hunting to insert it back against its gear.

Quote from: KevinCThe GS doesn't have a sprag type starter clutch. It has 3 cylinders that are spring loaded on ramps that bear against the crankshaft. It is on the left side of the engine, behind the alternator rotor.

That's it, what we're talking about.  It's an overrunning type starter clutch of the sprag type.  The one in the GS is of the roller-ramp type.  I expect to be technically correct only the ones with the rectangular type elements should be called sprag type and the ones with the rollers  like the GS should be called roller-ramp type.  We mostly called them all sprag type as opposed to the bendix, solenoid, etc types found in automotive type applications.  

Here's a roller-ramp type made to replace Ducati's sprag clutch.  You see they refer to it as a roller-ramp type sprag clutch.

http://www.ducatimeccanica.com/Howdi/default.html

Also a thing on BMW sprag clutch problems, thinner not thickers oils seems to be their answer.

http://www.ibmwr.org/ktech/sprag-clutch.shtml

I'm using the 15W-40 fleet oils now in all three bikes.  Have been for about a year.  Using the Mobil Delvac 1300 oil.

Srinath, you should just re-build that thing so it runs on normal oil! The GS has all those little oil jets to meter the oil flow everywhere, and I'm sure real thick oil is going to starve some parts.

I've got one brand new Suzuki first over-size piston and ring set, if you can find another.

Yeah, the starter gear is always engaged with the gear train. And you can pull the starter without touching anything but the sheet metal cover over the starter. Maybe you have to pull the tank and carbs to get to it.

QuoteI have 1 qt 20/50 in it with 2 qts Lucas oil stabiliser... That thing is like paste...

uh, if your gs is Requiring this mixture to run, yeah, time to do something about it. only reason i use 20/50 or straight 40 is cuz it gets so damn hot down here in south fla, and traffic jams do happen, 10/30 and 10/40 get too damn thin for my liking. i havent used any synth lubes at all.  even though its a ramped/roller overrun clutch it still falls in the original tacumsa lawnmower/edger pullstart clutch, the non plastic rebuildable 4 ball bearing SPRAG clutch design.  its mearly refined. no, turning the wheel wont help, the lightbulb trick, or heated garage bit might work. but watch out for fuel leaks and fumes.  when its like 50-60 degrees in south fla, thats bloody cold to us and our cars. after about 20 mins of pumping the damn starter button over and over cuz clutch didnt want to grab long enough to start the engine. i put a 60W bulb under the engine near the starter clutch area over night.  didnt have an issue then, cept 8 hours latter at work, but then it was warmer out and wasnt so bad.

Well Lucas oil stabiliser isn't needed to run it... I can quit anytime... yea I can man...
Never mind... The oil leak really gets worse with any other type of oil, not to mention the burning... However it was so hot from May to sept... I prefered to use that. I'll switch to the 20/50 soon. Just wanted to wait another week before I did it....
Cool.
Srinath.

where are the leaks srinath? clutch pushrod? countershaft? oil pan? Unless your missing CHUNKS of gasket in places, there are things you can do to bandade the leaks and not require cookie dough to lube your engine, the ages of shoe leather bearings and sawdust in the crank are past. just from the # of bikes you have mentioned and watching you give advice on this board, i know you have the wrenchin knuckles to make this better dude.

Yea... But I am Laaazy... Never mind... House stuff is keeping me bussssssssy.... anyway lucas oil additive makes oil stick better... Cams were slippery with it when I opened to adjust it, the dip stick part above the area immersed in oil also has oil on it all the time... Its real sticky... I dont think pumping it takes more time either... The oil light goes off quicker on cold starts. The stuff is different from 40wt ... It dont increase viscosity I think... Just makes it stick. Now I probably have too much of it in the bike for the present weather... 1 qt of it to 2 oil should be my winter mix... I dunno, it is my frist experience with it. The gaskets are getting a good look soon...
Cool.
Srinath.

You might want to try Castrol GP 20W50 (mineral) It cuts on oil-consumption and  also seems to stick very good to engine parts, at least better than the Shell semi-synth. Also very good at high temps.  Think riding uphill at 5 km/h,stop and go in 35C weather with the almost max. combined weight the GS can handle (365 kg) and for 10 mins long.

1 more point: it isn't expensive  

OK changed the goo and put oil in it instead, 10W40, its been cold around here... and the clunk is still there. So The oil is not it. However the 10W40 might make the oill seepage much more obvious.. and I'll fix it at last. But the clunk... what gives... or is about to give...
Cool.
Srinath.

What about the oil pump? The light goes off quicker, but does that really mean the pump might not be wearing out? Is the clunk consistent like JamesG mentioned regarding the starter clutch bearings?

Well oil pump light takes the same time more or less to go off. The noise is from right under the carbs.... where the starter is... Also doubt if the oil pump will make this noise and still make any pressure. It disappears when warm, or when the bike is running.
Cool.
Srinath.