Damaged something welding to frame

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Austblue

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G'day,

I had a friend weld some tabs on my bike's frame today and I believe that I've damaged something and I'm looking for some advice.

Before welding anything I disconnected the ground connections, removed the coil from its mounts, disconnected the rec/reg and pulled the fuses from the panel believing that was adequate to protect the electrics. Unfortunately I didn't consider having the welders earth close to the job and we left it on the horizontal brace under the seat while welding at the front down tubes and a couple of tabs on the sub frame.

I'm running a capacitor with a Pamco unit and high output coil, HHB PMA and custom wiring. Bike was running fine before today, did 100miles just the other day.

So after reassembling the bike it wouldn't kick over and something strange I noticed was when I replaced the fuses and earths the headlight came on for a moment which indicates that the cap had some charge in it but of course it quickly drained. I pulled the plugs hooked them back up to the leads and earthed them to the frame and kicked but saw no spark.

I checked the fuse panel and all were intact except I am pretty sure that the headlight fuse was blown so I replaced it.

I then hooked a 12v battery up to the ignition and retested and had spark so I re-installed the plugs and the bike kicked over. I didn't let it run more than 5s and didn't rev it at all but it idled.

I pulled the pamco side cover off and had a quick visual inspection of the board and could see no signs of damage/burning but didn't pull the rotor off.

Given that after welding the bike ran with a separate power source and the cap was able to power the lights this is leading me to think that I've done something to the PMA but not sure what to do from here. At a guess if it is safe to do so I would think that I could leave it powered off the battery and kick it over and go buy a multimeter and read the PMA output either side of the rec/reg and cap but not too keen to race ahead without some educated advice.

Thanks for any help.
 
People don't seem to realize that welding produces a huge magnetic field. It's not so much the huge electrical current that does the damage.

The fact that you could get the engine started again would seem to indicate that the PAMCO is OK. It either works or it doesn't. I don't know what is in the PMA regulator, but my best guess at this point is that you cooked the regulator....:eek:

Any damage to the electronics, including the PAMCO and the PMA regulator will not necessarily be evidenced by burnt components etc. The huge magnetic field actually destroys the internals of the solid state devices, transistors, IC's, chips etc. It's like the infamous neutron bomb. It's bloodless......:wtf:

Lecture time: :banghead:

Every year we get at least two cases of a welding misshape. It's real simple. If you are going to weld, remove ALL electronic parts from the bike before welding....:thumbsup:

Now, someone will join this thread and say that they have been welding for 45 years and never had a problem. Those people are extremly lucky. Follow them around and bet on whatever they bet on :D
 
Thanks for chiming in Pete. Regulator was on the bench as the plate I had welded on was to mount it. Apologies if this is a silly question after you've just said remove all electrics but does that include the PMA?

I just got a multimeter so will test it out now.

I just noticed too that when I hook the battery up to the ignition as I remove the power it lets out a "choof" from the air filter area. I have no idea what that is?!
 
the 45 year thing is the torque wrench thread.
Ive tried to tell peeps not to weld with motor in. It doesnt matter how close the ground is, its ALL charged during welding. It puts little pits in bearings and high tolerance items.
Im guilty of it t00
 
Put a multimeter off the reg reg output and I'm getting 150-400mV

Is there a way to test the output directly from the stator? What should I be reading off the each of the three yellow wires?
 
Austblue said:
Put a multimeter off the reg reg output and I'm getting 150-400mV

Is there a way to test the output directly from the stator? What should I be reading off the each of the three yellow wires?
Click to expand...

I read around 2-5V off each of the 3 yellow wires at idle and at revs :(
 
wow am i glad i read by chance. here i was ready to let my buddy do some welding on my bike and never even thought about this. now should i take everything electrical out? even wires? what about the motor? is there any way to ground the welder to prevent this from happening? taking everything electrical seems like more work than its worth to put a couple tabs on. also about that poof ive gotten that too and dont know what it is either so any answers would be awesome. thanks again
 
toplesschevy said:
wow am i glad i read by chance. here i was ready to let my buddy do some welding on my bike and never even thought about this. now should i take everything electrical out? even wires? what about the motor? is there any way to ground the welder to prevent this from happening? taking everything electrical seems like more work than its worth to put a couple tabs on. also about that poof ive gotten that too and dont know what it is either so any answers would be awesome. thanks again
Click to expand...

That's why I posted this up rather than just PM - I thought I'd done enough to protect my bike but I still stuffed up so I figured others would benefit from the lecture I knew I was in for :D

Still not sure what to do now though :confused: Any tips on what to check for in the PMA or what would need replacing?
 
Austblue said:
Thanks for chiming in Pete. Regulator was on the bench as the plate I had welded on was to mount it. Apologies if this is a silly question after you've just said remove all electrics but does that include the PMA?

I just got a multimeter so will test it out now.

I just noticed too that when I hook the battery up to the ignition as I remove the power it lets out a "choof" from the air filter area. I have no idea what that is?!
Click to expand...

Well, I wish I had known that the regulator was sitting on the bench. :doh: Details matter when you are describing a problem. :thumbsup: It's possible that you just did not reinstall the regulator properly, or if you painted the new mounting plate, then maybe you are not getting a good ground to the regulator. Did you paint the new mounting plate? Is there anything else you are not telling us? Huh?? :wtf:

Maybe you are one of those lucky for 45 year guys.:laugh:...44 years to go!:D
 
Last edited:
On the poof or choof, the Ignition fires when the current flow through the coil stops. When you turn off the power current flow in the coil stops. This fires the plugs even if the engine is not running. Often this extra spark happens with an intake valve open. Any unburned fuel in that chamber will fire up and burn. Thus the poof or choof from the air cleaner.
If you had the stock airbox on the bike you wouldn't hear the noise. It would muffle the sound. The same thing happens as often with an exhaust valve open, you won't here that because the muffler quiets it so much you can't hear it.
Leo
 
pamcopete said:
Well, I wish I had known that the regulator was sitting on the bench. :doh: Details matter when you are describing a problem. :thumbsup: It's possible that you just did not reinstall the regulator properly, or if you painted the new mounting plate, then maybe you are not getting a good ground to the regulator. Did you paint the new mounting plate? Is there anything else you are not telling us? Huh?? :wtf:

Maybe you are one of those lucky for 45 year guys.:laugh:...44 years to go!:D
Click to expand...

Hmm you're right, sorry I thought I covered that by saying that it was disconnected but I can see how that's different. Regulator has its own earth wire but then I didn't paint the plate yet anyway.

I'm doing my best, mate. Sorry for misleading with disconnect vs remove don't want to waste anyone's time.

So with the low readings I got off the yellow wires out of the PMA doesn't that indicate something in the PMA is stuffed?

Cheers.
 
When I had some tabs welded on my frame I thought I had pooched my Pamco.
After tracing my wires I realized it was a bad ground.

Not saying welding won't fry electrical, but do some testing before replacing anything.
 
Yeah I've already disconnected and reconnected the earths, PMA and rec/reg but I'm going to disconnect everything again and reconnect it because I'm hopeful that is it.
 
I just rewired it and put a different capacitor on and it still didn't start. Also Just noticed that the main fuse had blown - I had definitely checked this and it was fine before testing with the multimeter the other day so must have blown then I expect.

I then pulled the rotor off and found that it was very tight to get off and it was magnetically attracted to the rotor whereas my understanding was that it should be repelled.

Is this my problem?
 
New question... how does one delete a thread :doh: j/k

I put a new fuse in and out of desperation thought that there was a chance that the fuse was always blown and wasn't visible so at the 11th hour before I go away for work for the fortnight I put a new fuse in it then rechecked all the connections and something urged me to give all of the earth connections a tug to see if they'd come loose as it wasn't visible under the heat shrink. I couldn't believe it when the rec/reg earth wire slid out :wtf: Earthed that wire and kick started and it roared on the 2nd kick :eek: :yikes: :doh: I had removed and reinstalled all of the earths about three times but because I'd heatshrinked the ring lugs onto the wire sheath it wasn't obvious that the wire had come loose and I must have accidentally not soldered that ring lug onto the wire.

As frustrating as the whole thing was/is gee it felt great when it kicked over!

Sorry to waste people's time and thanks for all the help and suggestions it has been very much appreciated. Hopefully still serves a lesson for others planning on welding their frame. :bike:
 

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