Hello everybody

I bought a 2009 GS500F last year and it's had some ongoing problems. The first thing that happened was it started losing power intermittently, jerking and bucking while riding. When this happened it became virtually unrideable, and if I stopped the bike and tried to start it up again nothing would happen. Around the same time that started happening it also began to sometimes just click rapidly when I tried to start the bike (or the lights wouldn't come on at all and nothing whatsoever would happen when I pushed the ignition button). I took it to a repair centre and they replaced the regulator.
For a few months after that the bike ran completely fine, but recently the same issues have been cropping up. Predominantly it's been the electrical issues (no lights at all when turned on or just rapid clicking when ignition button pressed), so I tested the battery and it seemed ok (12.5V measured. The battery is a MotoBatt MB10U, bought April last year). But yesterday while riding the bike did it's jerking and bucking thing again.

So basically at the moment when I try to use the bike I could get any one of these scenarios occurring:

- Turn key to on, nothing at all happens
- Turn key to on, lights come on. But when I push the ignition button all I get is the rapid clicking noise
- Turn key to on, lights come on. Push the ignition button and bike starts (either with some clicking first or no clicking at all)
- Bike starts fine and rides fine
- Bike starts fine, but then while riding loses power and becomes jerky and unresponsive

Any and all help would be greatly appreciated, thanks.

There's 1 big 20amp main fuse in the bike, replace that first. when this goes out, NO lights on the bike come on. nothing happens.

the clicking you're hearing is the starter relay, there's not enough battery juice to get the starter to turn, hence it clicks rapidly. - nothing broken here it sounds like

battery should read charged, standing still, 12.9v-13.7vish range as well.

you have a multimeter, right?


The jerkyness sounds like it could be carb issue, but lets just try to keep the bike running first, eh? lol normally a imbalanced carbs will give you jerkyness you feel at around 35mph/52kph+

but also can be caused by a loose connector, look at each side of the sparkplug boots, trace the boot wire up, there's this black plastic thing mounted with 2 bolts to the bike frame, there's 3 wires, the sparplug wire itself, and two dinky smaller wires I know the positive is orange-white wire. but sometimes the metal female connectors can get loose and barely be on there kinda just dangling and you're gaining/losing that sides spark as you hit bumps n' stuff.

Thanks for the reply

So the bike seems to have regressed.... now nothing at all happens when I turn it on, no lights or anything over a period of a few days. I checked the battery again and it's reading 12.8V. I checked that main fuse too and it looks normal, doesn't look blown

Any other suggestions at this point?

you get power to the dash?

No, no power at all. No lights

Do some wiring and bypass the starter solenoid to check. I had similar symptoms and the starter relay was the culpret. Battery voltage was still good but I'd get a click when I'd push the start button and the dash lights and head light would go out. If I shorted the two major battery / starter post together with a screw driver the bike would turn over quickly and start fine - i.e. not a battery voltage issue.

To get me by I ran 12V and ground into the connector that goes into the starter relay and used a big screw driver to short the battery to the starter motor lead on the relay. This worked fine for me for a week until a replacement starter relay turned up.

Not saying that it is definitely your issue but if you wire the bike to bypass the starter relay you can rule out if it is the relay or not.

I tried to bypass the starter solenoid, but not sure if I can even test that at this point. No lights come on at all, no power, no clicking when I push the start button.....

I re-checked the fuse and even though it looks fine I replaced it with the spare. Still nothing

Also, I checked the voltage of the battery when the bike's off and on - 12.75V off but drops down to 0.06V as soon as I turn the key to ON. Does this mean anything?


Thanks all

Quote from: Davian on November 23, 2017, 10:15:51 PM
I tried to bypass the starter solenoid, but not sure if I can even test that at this point. No lights come on at all, no power, no clicking when I push the start button.....

I re-checked the fuse and even though it looks fine I replaced it with the spare. Still nothing

Also, I checked the voltage of the battery when the bike's off and on - 12.75V off but drops down to 0.06V as soon as I turn the key to ON. Does this mean anything?

You may be chasing more than one problem.

It's a common logical fallacy when encountering something like this to assume a common cause among problems when each problem by itself has a high-probability cause that is unrelated to the other issues.

Taking your issues one at a time:

Your current problem has two likely causes:
a. highest probability (by far): the battery is dead. Why? either it's a bad battery (possible) or it simply didn't get charged by riding (probable). To check this, charge the battery with an external garage type battery charger in "overnight" mode. Check the voltage when charged is 12.8V or so. Repeat the test. if the bike starts ok after forced charging, then you can rule out the battery as the sole cause
b. you have an intermittent short or open, and it's currently behaving badly (either short or open), causing the battery to rapidly discharge as soon as you apply a load, OR, causing an open circuit when you apply a load. First determine if it's short or open. Disconnect the battery, measure the resistance standing idle between the positive and negative battery terminals with a good accurate VOM. This should be very high, like 100s of K ohms or more. Now press the starter button and take the same measurement. It should remain very high because no battery is in place to provide power to the starter relay. If both of these numbers are high (100K+) then you don't have a short. If they are low (10s of ohms) you have a short that's draining the battery rapidly, which is why the battery is dead and won't charge.
Once you determine whether it's a. or b. proceed accordingly. Fix this problem by itself.

Next problem: intermittent behavior when starting. Sometimes lights come on and the bike starts, sometimes lights don't come on and no joy trying to start, sometimes lights come on but starting causes just clicking. This could have multiple causes.
a. most likely, poor electrical connection in the charging system, failing regulator/rectifier, failing stator. You have to check all three. By far the most likely is that there is a bad electrical connection. Could be anywhere from the stator wiring all the way to ground and all the way to the starter itself. You have to manually check everything. this is a good time to clean everything you check with a good contact cleaner/lubricant before reassembly. Whatever the cause, a detailed check and reconditioning the mating surfaces will likely fix it. Notice this is related to cause (b) for the starting problem above
b. less likely, intermittent short in some component (starter relay, ignition coil, a light, connector, horn, etc.) causing rapid battery drain whenever the short is engaged. So really this is a cause of a dead battery, and the battery is becoming dead because something is draining it rapidly when you don't know it. Could be any number of things including just worn wiring insulation somewhere causing a wire to touch the frame off and on and when that happens it drains the battery quickly. Notice this is similar to cause (b) for the starting problem above
To diagnose these issues is the same: trace the wiring and use a multimeter to measure resistance everywhere. You need to become super intimate with the wiring diagram. There are several relays that could be involved. Most likely here is the connector between the stator and the regulator/rectifier (not the bullet connectors, but the plastic one) is melted down and this is causing everything bad. But you probably also have worn wire insulation somewhere and if it's anything like my bike, in multiple places, so you probably need to inspect every inch of wiring anyway and fix all of it. It's time consuming to pull all the wiring out of the looms and run over it all but if you're chasing issues like this there really is no substitute.

Next problem: electrical failures while running. Bucking/jerking and dies and won't often restart.
a. most likely: one of the above things is causing the battery to be dead and it eventually drops below the level needed to keep the ignition on. Follow up with "why my battery is dying or is it just bad" as above.
b. less likely: but still could be, bad ground connection. If the ground connection is intermittent it can cause this kind of behavior and also cause hard to diagnose charging issues. You'd see the lights blinking on and off in that case. Could be a local ground problem. Chase all the ground from the ignition coils, engine block, etc., make sure connections are good and clean and tight. Notice this is related to causes pointed out above
c. far less likely but someone here on the forum will bring it up: the signal generator is failing. This is usually heat related. It will cause intermittent misfire or complete dying when hot, when it cools it may restore working.
d. even less likely but still possible: this is not electrical, could be bent valves or zero valve clearance, when the engine heats up enough you have poor compression and the bike won't want to run at low RPMs. it behaves just like if it had a failing ignition coil or signal generator, but those parts test good and you have low-ish compression (under 140psi) then this could be the problem.
e. even less likely but possible: not electrical, it's fueling. sticking float needle valves cause the float bowl to intermittently go empty and starves one cylinder for fuel, bike wants to stall and manifests as bucking/misfiring and dies at idle. Eventually the float needle stops sticking long enough to get fuel into the carb and it starts and runs like normal. Maybe in effort to get it to restart you drain the battery.

Note you could have multiple problems here. You could have the sticking float needle valve and a bad battery and an intermittent or poor connection from the stator to the reg/rect and it all manifests as these problems together. Then if you fix one (say, replace the battery) then it still does most of what it did before but now the battery holds a charge much longer between manual charging, so you go longer between times when it just clicks and won't start at all. Then you fix the float needles and still the battery doesn't always charge or takes forever to charge. Eventually you need to isolate the problems one by one and fix them all.

It's an old bike. Probably lots wrong with it.

Ok, so I believe I have fixed the problem now. But perhaps I've fixed just one issue and there are potentially other things to look at, so I wanted to run it by you all.

First off, huge thanks to all who responded, it's avoided a huge hassle and cost getting it to a mechanic.


So, turns out I just embarrassingly overlooked something..... I thought I had checked the battery terminal connections properly but I had not. There was a fair bit of corrosion and dirt going on at the negative terminal, so I cleaned that up and tried the bike again. Lights turn on, bike turns on no issue. I haven't got to test ride it yet, but everything so far seems back to normal. My question is - does this poor connection explain all the issues detailed above? Or do I need to look further as well (perhaps into the carburetor still?)

Again, thanks all for the detailed answers. It may have been a stupid little thing to overlook, but I'm new to all of this and I learnt a lot during this process.

Cheers!