1980 xt Yamaha earth issue?

my guess would be the tank is either rubbing the plug lead or pushing the lead onto the frame.
Old XR's and TT's had no battery,, XL's and XT's did.

Definitely as others have said the HT lead is touching the frame somewhere and you are grounding it. It is not the earth wire off the coil as this is the low tension side and won't shock you.

Could be a primary voltage as opposed to secondary which would make more sense as this is what the kill switch will be connected to. Maybe the switch that is used is faulty.or the earth between the Frame and engine is poor

Ah, thanks Muzz, yes I was thinking TT. Not XT.

Um, the Kill Switch works by earthing the magneto to the frame, so if you have it earthing that side of the coil, then the bike won't run at all.

mag to coil is the primary ignition kill switch earth's this a if the frame is not earthed to motor push kill switch primary voltage flows through frame (back emf from coil) enough for a descent shock or the mag wire has a short to frame somewhere with a poor earth to frame so it doesn't kill engine and switch is earthed back to engine. I would of thought a secondary short in the ht lead would cause some noticeable running problems also the engine is grounded so should the frame so you should not get a shock even if it was shorting from ht to frame/engine

so did you answer the question, is this only when you touch the kill switch, or when you touch the frame at anytime the engine is running
you make it sound like a HT shock, yet if the HT was shorting out enough to shock you the engine would not run - thats why I asked the question
I can assure you if it was HT you'd see the spark jump from your balls to the tank, even through your jeans
I don't need the attitude, I asked you to clarify so I could try to help, I cannot help you if you start in with the defense mode,"yup I'm a hillbilly an I thik I'm too grate to bothert wid talkin pruper"

they were the first or among the early CDI ignition - they didn't run a mag, the kill switch was wired to kill the primary to the coil from the CDI box

the HT side will not fire if the primary side is shorting, if the HT side is shorting the plug won't fire, how to hell does HT side get routed through the riders body

if he gets a belt standing beside it, where does it come from, how does it complete the circuit back to the frame, leg stand?

cannot imagine why it is happening unless someone has been playing silly buggas with the wiring and deliberately set it up to belt someone,and that would take 2 points, one to deliver and one to exit, basic principal electricity follows a path, it won't belt you if it cannot pass into AND out of your body

I think they also used a wasted spark system, 4 stroke air cooled 248cc single banger, not a lot to go wrong with the electrics - heres a thought though, the battery coils could poke out 115VAC, the batt regulator and rectifier controlled that and limited it to about 16VDC, this particular one doesn't have a batt, wonder what was done with the wiring, could be he wouldn't be the first to think that 115VAC is the HT side of coil ( which patently if leaking the engine would not run), the 16VDC will run the lights as he notes, but if he was being put between 115 and earth he'd certainly feel it ( if he was between V and earth on HT he'd see the spark, big long blue buggas)
beetle, suggest you slip the side plastic off were the batt used to live and check all wires in that area are not bare, or touching the seat, also lift the seat, check the fuse connectors and plugs on the right side just under your arse when seated, if one of those where able to brush your leg, and you hand was on the frame it would give you a hurry up

The primary will be around 90v the charge coils about 20v ac before being rectified and the primary and secondary can both only give you a shock if something is not earthed or you are touching exposed cabling.

open circuit on my Yamaha lighting and charging coil is about 110-115vAC, thats direct off the coil, checked as it exits the coil cover
but yeah, all bikes may have different V rates, also depends on revs too I'd imagine

20V AC?, you'd probably feel that, the AC factor would lend itself to you noticing more than 20V DC would

point is that I suspect this kick he is getting is more likely to be from that than HT

would the coil work if primary was leaking?, I don't think it would, which would mean if the primary was leaking the engine would have no spark, ergo would not run

Hey mate, I apologize for my attitude at the time. I have replaced the sparkplug as it had a fine crack in it,still had the issue but the jolt was less,more of a tingle than a kick. I disconected the kill switch from the loom and it disappeared so now just turn it off at the key. One thing I did find that when the kill switch was connected it had spark to the plug even when the key was switched off so I,m not sure what that issue means but will sort it out when I put on a new kill switch. Thankyou and others for youre imput and knowledge. cheers AJ

thanks for coming back, the plug issue ( crack) will not be part of the cause, if the spark was leaking at that point the engine would not run, it will not only partial leak, - you've got upwards of 22000v at the plug and it WILL jump to the weakest link in the circle, ie you, not just part of it, all of it,stand more than your hair up can tell you that

the kill switch is the likely culprit, its carrying up to 90vdc and has an ac factor, all the switch does is earth that primary to chassis, ie handle bar or back down the loom to an earthing point ( check that - they usually have a black wire earthed to chassis in around the steering head somewhere, has a lug on it that is screwed to the frame - not to the front forks system), the switch portion you touch is usually plastic so won't carry current, but some of the earlier ones were steel covered plastic, and the cover wears thin

grab a spare left handle off a quad, all the yamy's used the same switching on all their quads

90v is enough to give you a good tickle, 20v lighting will give you a wee tingle, the key kills supply to the reg and the black box thus kills all spark, the kill switch also kills start operation on those with electric start ( quads)but doesn't kill other circuits ( ie lights, indicators etc, to kill them the key has to be turned off, but not an issue for you as there is no battery so as soon as the engine stops there is no batt to drain)

Check to make sure the forks and handlebars are earthen to frame. Then rewire kill switch. As per my original post.

Cheers mate, will check that out in the morning. AJ