Ok, so i arrived in Dayton for a rally to discover that something has gone wrong with my starting system. Push starting the bike got me through the few days that I needed it to, but now I want to fix what's broken. Upon pushing the run button, the starter spins nice and strong, but without any clicking (and of course the bike doesn't start either). It's too dark at the moment to go out and test my starter relay, so I want to get some quick opinions before I do so in the morning. Am I correct in assuming that the relay is at fault here?

The starter spinning means the relay is okay, it's supplying juice to the starter.  What's not happening is the starter gear engagement solenoid is not engaging the gear with the clutch basket.  I'd just pull the starter motor and make sure that gear slides in and out with ease.  Also, it may not be lined up properly, preventing it from engaging.

Hope this helps.  If one of the others more experienced with our starter motor, can correct me if I'm wrong, please do.

Ok Scratch my friend -- your idea is right, but the details are incorrect.

The GS has no solenoid to engage the starter motor with the crankshaft/drivetrain to turn the engine over, beginning the starting process.

The GS has a starter clutch, a mechanical gadget, located behind the generator rotor on the left hand side of the engine.

Some possibilites are:

Starter motor is loose in the housing -- this is Scratch's idea -- make sure that the teeth are still on the starter motor shaft. There are only two screws holding the starter motor in place.

Starter motor is running backwards -- not likely unless some serious rewiring has occurred. The starter clutch slips when the crankshaft turns faster than the starter motor and idler gear.

Starter clutch springs are broken or the "dogs" that grab the crankshaft are worn out.

To see my FAQ for details on how the whole things works CLICK HERE.

Ooh that does help. Thank you to the both of you. 

Your are welcome!

One warning though, you can't get what you see in the FAQ without either draining the oil or leaning the bike WAY over on the right side (this moves the oil to the right side. If you do go into the LH side, you will probably need a new gasket.

You are also looking at dealing with stator wiring, clutch pressure gadgets, LOTS of stuff to get to the pics you see in the FAQ.

BTW, the starter motor is under the carbs, under a cover. Just follow the starter wire from the starter relay.

And another thing...if you pull the starter motor, do not try to unbolt the starter cable by just spinning off the nut. You will probably wreck the starter innnards.

You need to hold the threaded shaft still and rotate the nut. This is easier to visualize than describe.  But perhaps I have told you too much already....

Ack it'll take more work to diagnose than I expected. If I'm understanding the situation correctly, I have to drain the oil, remove my case guards, and order a gasket for the left hand crank case cover just to see if the starter motor gear is lining up with the starter clutch gear correctly. Then I have to make a tool with which to remove the rotor so I can determine whether I need new springs or rollers, and THEN keep the bike opened up for a week or so while I wait for springs/rollers to ship. This is sounding more and more like a winter project rather than a few-hour job. I think I'll suffer through push starting the thing until the first snow falls. And here I was hoping you'd just say "get a new starter relay and you're all set", thanks starwalt.     

Or is it possible to see if the starter motor is lined up correctly by looking in through the top cover?

You are welcome...I think.

The simple approach is to remove the starter motor, under the cover under the carbs, and see if the teeth on the shaft of same motor are in good shape.

Here's a picture of a GS400 and GS500 starter teeth. The GS500 is on the right. Click on it for a big view.


Notice the wear on the right side teeth. This is where the starter motor engages the idler gear. The idler gear engages the starter gear.

It is a bummer to get to, but unless you want to pony up the $$ for a shop, you have to get a little dirty. I had to get there to fix mine.

I hoper your starter motor is just loose under the cover. If so, you may be able to just tighten up the mounts. If it is loose, you need to inspect the teeth you see in the photo for damage.

So Scratch, how did you manage to pull off your rotor? I've been trying all day with no luck. I fabricated a "sliding-hammer"-type puller tool as Clymer recommends, but the threads on my rear axle are the wrong size! I think the pre-01 GS had the correct thread size, but not later models. And to top it all off, none of the local hardware or big-box stores sell a long enough metric bolt. The best I could find was a 100mm long bolt (12mm x 1.25mm), and attached a round dumbell weight to it, but that didn't work. Any idea where I can get an aftermarket rotor puller?

I made mine as seen in THIS PHOTO THREAD.

The thread size is 14mm.

I heated the center part of the rotor, on the crankshaft, prior to pulling it.

Just a few words of advice if removing the rotor:  Don't lose your patience because replacement rotors are costly.  Do the job right--don't grab it with a bearing puller--and avoid the heat except as a last resort (heat can degrade the magnet adhesive).  If you can't get it, load it up and haul it to a dealer.   Cheaper than buying a new rotor. 

If you have a motorcycle junkyard nearby, you might run by there and pick-up an axle with the appropriate thread.  If you tell them what it's for, they probably wouldn't charge much.  I do know the front axle from an RD350 will work (that's what I used).  Probably lots of other models would work as well.