How do YOU jump start an old GS?

[OriginalOwner]

Suzukian > good idea but this battery is sealed.


Rich82GS750TZ >
Key on: 12.6 volts
key on while pressing the start button: 11.9

...then the starter motor seizes up and the voltage drops exponentially. I think I gotta get that thing outta there and rebuild it. It's never really been right - I always chalked it up to an engineering flaw thinking that the recommended battery was wasn't powerful enough for this engine - or maybe my timing was slightly off. Who knows?

Maybe after 42 years, I'll finally get it squared away.

PS - I could be wrong but as I remember it, '81 was the first year manufactured without a kick-starter - having one would have saved me a whole lot of grief over the years. I KNEW that was a bad idea on Suzuki's behalf.

[Rich82GS750TZ]

Pretty sure ‘79 was the last year for a kick starter. No matter. ‘80 GS 750 chain drive models were the first yr for the 16 valve TSCC engine. None of those had a kicker.

Sounds like taking the starter motor out and apart is a good course of action. Well, it’s what I’d do anyway. Admittedly, I don’t always know what’s right.

[rphillips]

Also don't matter but no GS1000, including "78" had a kicker.

[Suzukian]

If the starter motor were seized up, it would be sucking up a lot more voltage than that. Try jumping the solenoid and see if the starter motor turns over. (make sure the bike is in neutral and on the center stand). You can just take 2 large screw drivers and on the large terminal ends of the starter motor, touch the screw drivers together to make a "jump" (or make a far jumper wire, there's a lot of current there). If the starter motor sparks, but doesn't turn over, then you have a bad starter motor, make sure you press hard, as they will spark at first. If it turns over, then you have a bad starter solenoid, or a bad connection to the starter solenoid.

You also could just try applying 12 volts directly to the starter solenoid lead at the starter motor (the skinny wire), that will test the starter solenoid. If it turns over, then you have a lose connection somewhere. The 2 heavy wires are one from the battery to the starter and the other side of the starter goes into the starter motor, for clarification

[OriginalOwner]

If the starter motor were seized up, it would be sucking up a lot more voltage than that. Try jumping the solenoid and see if the starter motor turns over. (make sure the bike is in neutral and on the center stand). You can just take 2 large screw drivers and on the large terminal ends of the starter motor, touch the screw drivers together to make a "jump" (or make a far jumper wire, there's a lot of current there). If the starter motor sparks, but doesn't turn over, then you have a bad starter motor, make sure you press hard, as they will spark at first. If it turns over, then you have a bad starter solenoid, or a bad connection to the starter solenoid.

You also could just try applying 12 volts directly to the starter solenoid lead at the starter motor (the skinny wire), that will test the starter solenoid. If it turns over, then you have a lose connection somewhere. The 2 heavy wires are one from the battery to the starter and the other side of the starter goes into the starter motor, for clarification

So, I just started it with the bigger, higher amperage charger. In your opinion, does that rule out the solenoid or the solenoid connection? Or even the starter motor?

Is my issue simply just a weak battery?

F*ck! In 42 years with this bike, I have never got more than ONE friggin' year out of a new battery. WHAT BATTERY do you guys buy/like?


rphillips > FYI - Instead of the vice grips, I used these 2 random battery clamps that I had laying around - I think I might have hoarding tendencies.

And they worked perfectly!!
image.png

[Suzukian]

I start off with a 10 amp battery for 10 minutes, then go to a 2 amp, sometimes the 2 amp batteries can break into the cells, especially if they have any sulfate on them. I purchased a new Schumacher charger that has a high frequency setting to knock off any Sulfur it detects, it also does standard, AGM, and has a 2 amp setting.. It's all digital, kind of small, and has been the best one I've had yet. The most I can coax out of a battery now is maybe 3 years, but usually two, and I had better be riding the bike al lot. They don't make motorcycle batteries like they used to. I used to get 5 years out of a YUASA Battery, but not now. I keep them on trickle, automatic 1.8 volt chargers, but they end up steaming all the electrolyte out, and you have to add distilled water, which I'm sure deteriorates the batteries state.

So the bike did start? IF it did, it means that the battery reading you are getting with the AGM is just a surface charge, not an indication of the amps it's able to produce. That's why I stick with conventional batteries, at least I can see the electrolyte levels, and check each cell with a hydrometer. If you bike did start with a larger source load, it means your battery is probably shot Some starters will take more current when they start to go, but Suzuki makes a really robust starter. Mine has lasted 40 years, and spins right over.

Make sure you check the ground lead from your battery, all the way down. On a lot of bikes those years, Suzuki grounded the battery to a painted spot on the engine, relying on the bolt threads to ground the battery. This caused electrolysis to occur, and you end up with a really bad ground, which wreaks havoc on the bikes charging system. If this is the case, scrap that surface down to aluminum, apply a little dielectric grease so no oxidation in any area that isn't covered with the bolt won't oxidize, and use a new bolt, and tighten it, clean the ground connector too, so it's nice and shiny., then you will have a good ground. This creates a level playing field for the electronics. The batteries sold at Walmart are made by YUASA, can you believe that!!

[OriginalOwner]

I start off with a 10 amp battery for 10 minutes, then go to a 2 amp, sometimes the 2 amp batteries can break into the cells, especially if they have any sulfate on them. I purchased a new Schumacher charger that has a high frequency setting to knock off any Sulfur it detects, it also does standard, AGM, and has a 2 amp setting.. It's all digital, kind of small, and has been the best one I've had yet. The most I can coax out of a battery now is maybe 3 years, but usually two, and I had better be riding the bike al lot. They don't make motorcycle batteries like they used to. I used to get 5 years out of a YUASA Battery, but not now. I keep them on trickle, automatic 1.8 volt chargers, but they end up steaming all the electrolyte out, and you have to add distilled water, which I'm sure deteriorates the batteries state.

So the bike did start? IF it did, it means that the battery reading you are getting with the AGM is just a surface charge, not an indication of the amps it's able to produce. That's why I stick with conventional batteries, at least I can see the electrolyte levels, and check each cell with a hydrometer. If you bike did start with a larger source load, it means your battery is probably shot Some starters will take more current when they start to go, but Suzuki makes a really robust starter. Mine has lasted 40 years, and spins right over.

Make sure you check the ground lead from your battery, all the way down. On a lot of bikes those years, Suzuki grounded the battery to a painted spot on the engine, relying on the bolt threads to ground the battery. This caused electrolysis to occur, and you end up with a really bad ground, which wreaks havoc on the bikes charging system. If this is the case, scrap that surface down to aluminum, apply a little dielectric grease so no oxidation in any area that isn't covered with the bolt won't oxidize, and use a new bolt, and tighten it, clean the ground connector too, so it's nice and shiny., then you will have a good ground. This creates a level playing field for the electronics. The batteries sold at Walmart are made by YUASA, can you believe that!!

Thanks! Will check that negative battery cable/ground first thing.

Yes, the bike started with the "larger source load" and ran well, sorry I wasn't more clear on that. I'll try your charger protocol, 10 amp to 2 amp but I realize there probably isn't much hope left for this battery. FYI, I have a "smart" .8amp (800mA) "trickle charger" but even that will fry a motorcycle battery if left to do it's thing. I use an old wind-up lamp timer on it and set it to run just for an hour, twice a day.

Do you buy/use the Walmart batteries? Can you suggest a battery to purchase for this bike? That question is really for anyone reading along, I'd like to hear anyone's personal battery preferences and experiences.

Thank you!!

[rphillips]

I've been using e-bay chee-po batteries for several yrs. now. For me are doing the same as others at appx. 1/2 the price. Several yrs. back, I decided to get a "Good" batt., went to Interstate and bought theirs. Got home opened the sealed Interstate box and found a YUSA batt. and an Interstate sticker, that could be stuck on the YUSA . I wasn't impressed... Also does anyone know of a Batt. tender or trickle charger that turns completely off when batt. is full charged, like many Batt. chargers these days? All I've checked out never turn completely off.

[Suzukian]

None of the trickle battery tenders I have actually "shut off'. Maybe it's the "Touring Principle", that a machine can't shut itself off and be truly off, then turn itself back on, therefore it must always be on, to turn itself on (Of course that my own summation, but that is the basics of it).

I use the Walmart batteries. The most I get is three years out of them, one time I didn't even get a year. That was a long time ago. I have a 1.8 trickle charger, and no longer keep it on continuously. Every now and then, I plug it in and within a couple of hours the battery is fully charged, and no fluid has evaporated out. It seems to me that back in the mid '70's to the mid '80's, batteries lasted around 5 years easy. I think they are purposely made cheaper. Sounds paranoid, but nothing else has changed in my bikes, the batteries just don't last as long.

[1978GS750E]

"Do you buy/use the Walmart batteries? Can you suggest a battery to purchase for this bike? That question is really for anyone reading along, I'd like to hear anyone's personal battery preferences and experiences."

Whatever battery you buy I would recommend getting an AGM sealed battery. No more checking fluid levels!

I use Interstate AGM batteries in all of my bikes and leave them on a Battery Tender Jr. all the time, year round. The oldest one is six years old! Maybe I'm lucky?

[Rijko]

Shop owner i know stores customer bikes over the winter period, paid service.
Collects the bike if need be, services it etc.

Had the batteries on trickle chargers all winter the first couple of years.

Then switched to 100% load at first and leave them without charger for a month.
Load 100%, leave them for another month.

He noticed a significant drop in batteries dying.

[rphillips]

I just replaced the batt. in my "83" GS1100 about a month ago, it had just lasted, don't remember exact date I had written on old one, appx., 2 yrs. but also when getting bikes started back up after winter nap, I saw the batt. in the "99" Bandit was put in in 2017 and all still good. Yes, these days AGM.

[Grimly]

Used to be I got 8 to 10 years out of a Yuasa wet-cell battery, but since 2012 the longest a Yuasa lasted was 3 years. I've been using Motobatt AGM since 2016 and 2017 and those two are still in service.
However, recent purchasers of Motobatt have complained of them not being as good as they were, so there's that.

[OriginalOwner]

My Suzuki Part No. is 33610-49210 (12V, 14AH)

12? 14? Is box size, right? Can't remember.

This one is 12 ah - this should work, right?


image.png


https://www.amazon.com/Mighty-Max-Battery-Maintenance-Motorcycle/dp/B01GEVSUJ6/ref=sr_1_1?keywords=14L-A2&qid=1689887719&refinements=p_85%3A2470955011&r n id=2470954011&rps=1&sr=8-1

[Rich82GS750TZ]

I’ve had an $40 AGM Might Max battery like that in the bike for 3 years. I’ll run it till it dies. I, too, used to replace my battery with a Walmart- add electrolyte at home battery about every year. I don’t thing there’s anything wrong with those batteries. made by Yuasa? Didn’t know that- interesting.

Difference is, I fixed my charging system. I would guess that is the root of your issues too. Plenty written here on the forum of how to test and fix your charging system. See Quick Test and Sorted links in my signature.

Link below to the Mighty Max that I bought because it was nearly the exact same size as the original. Realize that a battery even just a little taller that the original could give you problems installing the air filter box.

https://www.amazon.com/gp/product/B01GEVTMZW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Pay attention to the position of the POS and NEG posts. They may be reversed from the original orientation. I don’t recall. You may have to rearrange some things. Just be sure.

For what it’s worth, I keep the leads that connect to my Battery Tender Junior bolted to the battery posts. If I’m riding the bike regularly like March thru Nov, I don’t bother with the tender. In the winter I have it connected to a Christmas Light type timer 12 hours a day. Right or wrong, I don’t care. It works.