Smoldering while jumper-cables connected

[gsman88]

Firstly, I am brand-new to these forums and motorcycles...

1978 GS550

I was jumping the motorcycle because I was trying to diagnose ignition problems. The motorcycle has starting/running problems. The owner I bought it from, and me, have thought that it was carburetor related since it's quite an old bike, common problem, etc.

but when jumping and turning it over I had the spark plugs out and ground-jumped and noticed none of them are producing a spark. I was getting "antsy" thinking I've found the problem but when I came back down with my meter I noticed some smoke coming out from under the gas tank. I immediately removed the jumper cables and sat and watched to make sure nothing bad was going to happen.

I'm wondering if that was the rectifier.... I'm wondering if I found the problem and it finally burned up... or if I merely created another problem. If that last statement is true then I would be wondering this: "Can I not jump a motorcycle like a car?"

Some assistance, and restraint, would be helpful.

[bccap]

The car must not be running......

[Cipher]

coils got hot from not being allowed to discharge properly I assume.
Try doing one plug at a time.

[gsman88]

The car must not be running......

Thank you. I appreciate this. Really. It was suggested to me by someone that they got their motorcycle started by leaving the car running. I actually tried starting it yesterday using only a battery. But, as usual when listening to other people, I decided to try "his way" before actually looking it up to see if it was safe. It clearly is not.

coils got hot from not being allowed to discharge properly I assume.
Try doing one plug at a time.

Any other components that could have potentially been damaged? Would the magneto have been safe from this? I should mention that I took 1 plug out at a time, reconnected it to the wire, grounded the plug with another wire I had, then put the plug back in and reconnected it, moved to the next plug. But the car was running when I did this, as suggested by a neighbor.

[habsdoc]

Your neighbor was wrong and yes there is likely more damage now. R&R could be toast now.

[JJ]

Thank you. I appreciate this. Really. It was suggested to me by someone that they got their motorcycle started by leaving the car running. I actually tried starting it yesterday using only a battery. But, as usual when listening to other people, I decided to try "his way" before actually looking it up to see if it was safe. It clearly is not.



...But the car was running when I did this, as suggested by a neighbor.

Your neighbor was wrong. When jumping from a car, the car should NOT be running.

[gsman88]

Your neighbor was wrong and yes there is likely more damage now. R&R could be toast now.

I swear when newbies post people specifically try to use rarely-used acronyms just to make us look more stupid than we really are. What is R & R?

EDIT: I'm assuming it's Regulator/Rectifier. That took me a ridiculous amount of time just to figure out it meant something I previously mentioned in my first comment. *lesigh* C'est la vie, c'est la guerre, c'est la pomme de terre

[JJ]

I swear when newbies post people specifically try to use rarely-used acronyms just to make us look more stupid than we really are. What is R & R?

EDIT: I'm assuming it's Regulator/Rectifier. That took me a ridiculous amount of time just to figure out it meant something I previously mentioned in my first comment. *lesigh* C'est la vie, c'est la guerre, c'est la pomme de terre

Yes, R&R means Regulator/Rectifier. It's a standard acronym, not rare at all. On some earlier models, they are separate units. On later models, they are combined into one unit. I'm not sure of when the changeover date is, '79 I think.

[roeme]

I swear when newbies post people specifically try to use rarely-used acronyms just to make us look more stupid than we really are. What is R & R?

EDIT: I'm assuming it's Regulator/Rectifier. That took me a ridiculous amount of time just to figure out it meant something I previously mentioned in my first comment. *lesigh* C'est la vie, c'est la guerre, c'est la pomme de terre

Yeah, no, sorry, as others already have said, R/R is a bog-standard acronym - while it may take some time to figure it out the first time, it wasn't used in the way you are suggesting.

I assume that stems from you reading some other threads where newbies got themselves a bloody nose. Rest assured, just reading from your first post, you wont, as it is apparent you're willing to learn and are not one of the standard issue hur-dur-bike-wont-run-halp-me newbies who then get offended when one points out they're not following advice given. It's those who make people cranky.

Now, to the problem at hand.

The R/R on your bike is actually made up from two separate units. Looking at the schematics, assuming you connected your car to the battery terminals, and from what you've described, it sounds like the diodes in the Rectifier broke down, which in turn let the regulator trying to get the voltage down - a futile endeavor, given the power source. I recommend getting a SH775 R/R (it may take you some time to find a genuine part), it will remedy a host of potential problems with the stock charging system, which is sh!te anyway on this particular bike. Check the forums for more pointers on this.

It looks like the single/main 15A fuse hasn't blown, so overvoltage got everywhere:
- The life expectancy of all bulbs on at the time will be dramatically reduced (no idea if your model was one of those which let you turn off the lights),
- most likely your ignition coils are fried (Side note: the ignition system on these bikes is not a magneto one, but "battery/generator and coil" - refer to wikipedia for more info)
- you need to inspect all wiring harness connectors for obvious damage / discoloration, any existing bad connections, i.e. high-resistance, could've gotten hot with the over-voltage.
- also, it's possible that one leg (winding) of your stator got a visit from angry pixies as well, given a broken down rectifier.

Of course, the starter relay and motor got some extra juice as well, but I presume them to be okay, given that they got it for a comparatively short time.

My recommendation for your next actions:

1. Measure your coils, search the forum on how and what values to expect
2. Replace R/R
3. Measure stator windings, like 1), search the forum, replace as necessary
4. Inspect wiring/harness/connectors for obvious damage

Take pictures and report back as you go, this will get you the most help from the forum.

[gsman88]

Yeah, no, sorry, as others already have said, R/R is a bog-standard acronym - while it may take some time to figure it out the first time, it wasn't used in the way you are suggesting.

I assume that stems from you reading some other threads where newbies got themselves a bloody nose. Rest assured, just reading from your first post, you wont, as it is apparent you're willing to learn and are not one of the standard issue hur-dur-bike-wont-run-halp-me newbies who then get offended when one points out they're not following advice given. It's those who make people cranky.

Now, to the problem at hand................. [etc]

Take pictures and report back as you go, this will get you the most help from the forum.

Wow, I really appreciate this. I'll have to come back on my days off and read through this, do some work, etc. Thanks!

[bccap]

I did the same thing before I joined the forum. Had to spring for a new R/R. Do a search for recommendations for a replacement on this site. You don't want the original Suzuki one. Also check out any post posplayr makes and in his signature you'll see how to test your charging system.........

[argonsagas]

The regulator/rectifier AND the stators on GS-series bikes are known to be frail, and given to failure without outside interference, thus, as others have said, having a LIVE outside source for electricity is not good for them.

Also, as others have said, in every case, the engine in the vehicle with the good battery must NEVER be running at the time jumper wires are being used to start another vehicle.

In many of the more modern cars, for example, jumping while the engine is running can cause considerable damage to the electrical system on the vehicle with the running engine. For this reason some manufacturers recommend against using their vehicle to jump-start another.

[Burque73]

I used my F-150 to jump the forklift at my old workplace. Engine running, turned the key and the forklift started but the truck groaned and shuddered. After that the truck's alternator was toast.

In regards to the bike, thought I'd mention never to run the engine without a battery hooked up. Not sure why anyone would ever do that, but I did. Oh here's why, after a second battery died and before putting in a new one in I wanted to check charging output. Disconnecting the battery while running sent a power surge through the electrical system but luckily only the headlight bulb blew. I wound up replacing the R/R which is what ruined my batteries, adding a new ground, and of course a headlight bulb.