Hey guys/gals, been lurking for a while but recently decided to sign up.

Recently my '03 GS500E started sputtering at anything higher than 7000 rpm. Today I was out on the bike and after about 10 minutes it died completely, and wouldn't start again. After 30 minutes on the roadside, it finally started up again. I checked the lines for leaks and cleaned out the carb/jets. Everything looked alright; there was some sediment in the cleaner after soaking the jets, but it fired up okay after putting it back together.
Once the engine was warm, I tried to rev it past 7k rpm, but it died around the 7-8k mark, and now I can't get it to start again.

Any ideas as to what could be the problem? The bike was working fine up until a few days ago. Any insight would be appreciated!

EDIT: Shortened post.

You could be starving for fuel. I've noticed the 01 and later carbs are more prone to that.
But you're revving to 7k @ idle and then not starting ? You could have a bad ignition trigger pickup.
Its on the right side under that round hatch. Try spraying it with cold spray and see if it starts.
Cool.
Buddha.

Thanks for the reply, Buddha!

I also initially thought fuel starvation, but after cleaning the already-fairly-clean carbs, I'm starting to think it's something else.

I just pulled out the spark plugs and tested them to see if there was a spark...and neither plug had a spark (checked both plugs on both sides). They're visibly worn, but it's unlikely that both plugs died at exactly the same time, right? I'm almost certain it's ignition/electrical issues now. I just find it strange that they would develop seemingly out of nowhere. I took a look at the trigger pickup and nothing seemed unusual...but I'm not really sure how to test them.

Oh, and what is "cold spray"?

Thanks!

Quote from: airplaneman on June 12, 2017, 03:48:17 PM
Thanks for the reply, Buddha!

I also initially thought fuel starvation, but after cleaning the already-fairly-clean carbs, I'm starting to think it's something else.

I just pulled out the spark plugs and tested them to see if there was a spark...and neither plug had a spark (checked both plugs on both sides). They're visibly worn, but it's unlikely that both plugs died at exactly the same time, right? I'm almost certain it's ignition/electrical issues now. I just find it strange that they would develop seemingly out of nowhere. I took a look at the trigger pickup and nothing seemed unusual...but I'm not really sure how to test them.

Oh, and what is "cold spray"?

Thanks!

I think what he means by cold spray, is like a bottle of canned air, and holding it upside down and spraying it for a second to cool it down temperature wise.

That cold spray (yes upside down can of dust-off or whatever its called - compressed air) may work on a marginal trigger coil, but on a completely dead one, probably not.
I dunno, you may have to replace it. but no spark is a pretty definite indicator that its bad.
Could be TCI but lets hope not. The trigger pickup's die between 15k and 35k miles for sure, pretty much like a wear item depending on how it was used and how well it was made etc etc.

Cool.
Buddha.

Sounds like a bad pickup coil to me, typical bad coil symptoms.  The 03 had a single pickup coil I believe, we had no 03 models in US but single pickup coils started earlier in some markets, they first appeared in France in 1998. Hard to test those coils that don't fail until they're hot.  Might just have to replace it to see.   

Take the pickup coil off the bike and leave it in a warm oven for 15min.

Then carry out the static tests again.

Thanks for the responses guys.

The bike has about 40k on it, so a worn pickup is sounding more and more likely.

Will try the suggested tests for the pickup coil tonight after work. gsjack - you are correct, it is a single pickup.

Question: If I have to replace it, do I need a GS500 specific one, or can I get away with using something from a different engine? Or if mine is a single, can I buy a dual from earlier years and just take one off? The single GS500 ones seem to be next to impossible to find, but I can find plenty for snowmobiles.

OK you guys (GSJack and sledge) are both assuming its a marginal coil. I've had those happen to me as well, they fail only when hot and only when allowed to drop in rpm, as in you get on the highway while its working and hold it WFO it will run till - I guess the coil is dead all the way or till it runs out of gas.

However, there is also a dead coil - that is dead even at freezing.

Marginal = dead when hot. Easy to test. Wait till it gets hot, and hit it with cold spray and see if it comes back to life.
Dead coil = dead all the time. Cant test it without swapping over with a new one.

Cool.
Buddha.

Thanks Buddha.

If the bike won't spark at all, even when left overnight, wouldn't that confirm that the trigger coil is dead?

Yea, but could also be a TCI in some very special conditions or the usual "bad ground".

If the coil was cold spray fixable, you just proved the coil is the only issue.

Cool.
Buddha.

Ah, fair enough. I'll grab some air tomorrow and test after work.

Side note: Anyone know if I can just take one pickup off the plate of a dual-pickup bike (pre-00's) and re-mount it? Can buy a dual pickup locally from a part-out.

I'm believe the pickup is pretty much the same however it is wired up a little different as opposed to the single pickup design and I am not 100% sure there were no internal changes to the pickup. If the pickup is the problem you would be best to just pickup the right one for the bike. Either new or pulled from a known running bike. You will find them relatively cheap online if you go hunting or call up a local motorcycle wrecker they usually have the odd one kicking around.

Thanks for all your help, guys!

Posting this for future readers: the pickup coil was my issue; replaced that and she's running beautifully now.

Glad to hear you got your issue resolved!