gs550 stalls when warmed up

[airbornespud]

i had the same thing happen with my previous bike, a 550 Kaw. it would crank over, but not fire. charged the battery and it was fine. i always start with the simplest and least expensive fix first. in your case i would say the battery might be a little on the weak side. if you have some cells that are low on electrolyte, fill them up. you can use distilled water, but for less than $10 you should be able to get a bottle of battery acid at the parts store. charge it, fire it and see what happens. if nothing changes, you can eliminate the battery and find a friend with a little multimeter experience and check the charging system out.

[BassCliff]

Hi,

Have the battery load tested. Make sure it is properly maintained and properly charged. Then, once you have verified that you have a good battery, test the charging system.

Stator Papers
Stator Test

Stator Replacement

Regulator/Rectifier Replacement
More On The Stator Papers
GS Charging System Health+Quick Test
Battery Charging
Regulator/Rectifier Diode Test


Thank you for your indulgence,


BassCliff

[Planecrazy]

Welcome!

Yes ... first check the battery under load to verify it's actually in good shape. Once you are 100% sure the battery is good, do a charging system test (Basscliff's links, as always, should provide all the info you need on this, hehe!). I wouldn't be surprised if the R/R is bad. The original Suzuki units have a reputation for failing, and many of us replaced them with Honda alternatives which, once installed, are virtually bulletproof...

However, don't make the mistake of throwing money blindly at the bike. Verify each step before jumping to the next on false assumptions. Plenty of us learned "the hard way" that a skipped step can be costly. Hope this is helpful, and good luck narrowing it down!

BTW, where are you located? The GSR crew often likes to help new members if we're close by ... "It's what we do!"

Regards,

[suzi]

Thanks for the welcome. I will get right on the battery check in the am.

I live in Conway, SC (near Myrtle Beach)

Again, many thanks to all of you!

Will keep you posted

[suzi]

OK, I went ahead and replaced the batt (it was 3 yrs old anyway) and it seemed to help somewhat.

I did my usual ride it actually seemed a bit smoother throttle response, when warmed up. H owever, when idling for a couple mins it died. Still wouln't resart right away, but it did after a couple minutes, which is certainly an improvement. So, I figure it must be one of three things.

I already checked all connections and this bike is really clean, all were good.

R/R, sig gen or stator.
What do ya'll think?
Regarding R/R , I keep reading refernces about SHINDENGEN replacement.

Could someone please tell me which model to get. I'm a bit frustrated now and really don't care TOO much about bying a part unnecesarily.

We're only talkin about less than a couple hundred bucks, and it would be well worth it to get all this behind me.I WANT MY SON TO RIDE THIS THING! I KEEP SAYING IT ALL HAS TO DO WITH THE ENGINE WHEN WARM. It will restart but have to nearly run batt down to finally get it going. When it was cold today, just after installing fully charged batt, IT STARTED IMMEDIATELY
What should I do guys???

[Nessism]

Why not check the charging system before you spend $200 on parts you may not need?

[mike_of_bbg]

One common failure mode for the igniters on these old GSes is that they'll stop sparking when they get hot. More so than the coils I would suspect the iginter. My 550LZ did exactly that. The answer was a Dyna S DS3-2, which runs about $120. The coil relay mod helped with cold starting, as there was too much voltage drop from the battery to the coil.

One reason I think that igniters get damaged is because the stock Suzuki R/R allows the voltage to get too high. I did replace with a Shindengen R/R, an SH541-12 if I remember correctly. The stock R/R would put out 15.5V at 5kRPM, whereas the Shindengen clamps it down at about 14.6V.

http://www.ebay.com/itm/Dyna-S-Electronic-Ignition-Suzuki-GS550-GS750-GS850-GS1000-GS1100-77-78-79-80-81-/380382026185?pt=Motorcycles_Parts_Accessories&hash=item58908919c9&vxp=mtr#ht_1889wt_901

Edit: just checked, yes the R/R is a SH541

[Planecrazy]

Why not check the charging system before you spend $200 on parts you may not need?

I'll second this ... Basscliff left you a post with ALL the answers to the questions you have regarding proper testing of the charging (and other) system(s).

Spend a little time clicking those links and following those guides and you'll have the bike sorted out in no time, and without spending a dime more than you have to on replacement parts. Don't make the same mistake others have made by throwing money at the bike without actually knowing if that money needs to be spent.

Regards,

[Missile99]

Why not check the charging system before you spend $200 on parts you may not need?

+1 on this too. Visually checking connections is not good enough. Get instructions for the multimeter and use it. If you get confused as to what settings to use for a particular test, ask us. We'll even send a picture if need be.

You never said when it's warm if there is no spark from all 4 plugs or just one.
Check your electrical system thoroughly using all the info provided before burning up parts unnecessarily.

Heed Nessism's signature line, "To measure is to know." This is especially true when dealing with 30+ yr. old weather exposed electrical systems.