Motorcycle spark issue

[KINGPRAWN]

I have a Yamaha TR1 (xv1000) .. 1984 ... It's a Vtwin . The front cylinder has no spark . If I remove the plug connect into the cap and put it against the head "no spark " .... If I move it just away from the head sparks fly from all over the plug ..... Any ideas ... ( plug is new , as was the one I removed)

[Jim San]

Its a long time ago since I had bikes but i often had trouble with spark.

It ended up it being a cap, HT lead or plug or sometimes the lead earthing out on something.
I've never seen spark coming off from all over the plug but I have seen them jump form the cap to the cylinder head and that sort of thing

As its a twin, i'd swap the coils over and see if the problem goes with it

[KINGPRAWN]

Thanks .... All of that done ... Spark will jump from plug to head but not across the plug gap
.... Bonkers !!!!

[CovKid]

Duff plug/lead. Try substitution. If it sparks against head but not on its own. theres clearly no circuit.

[KINGPRAWN]

[quote="CovKid"]Duff plug/lead. Try substitution. If it sparks against head but not on its own. theres clearly no circuit.[/quote

Only sparks against the head if I pull i away from the head ... Then the Sparks leap across ... Touch it against and they stop ???

[windy]

Swap plug from front cylinder to back cylinder & try again. If the problem swaps cylinders then you know that plug is duff.

[CovKid]

I stand by what I said. When you're dealing with high voltages you do get seemingly strange effects when theres a fault.

Duff plug/lead. Try substitution. If it sparks against head but not on its own. theres clearly no circuit.[/quote

Only sparks against the head if I pull i away from the head ... Then the Sparks leap across ... Touch it against and they stop ???

[KINGPRAWN]

Thanks for the input Covkid

[KINGPRAWN]

all fixed now .... It would seem that using a resistor plug where one is not required can cause no end of headaches

[Jim San]

Well - you live and learn. Not that i ever knew a resistor plug existed or that i'm any the wiser for it. Glad you have it sorted though

[KINGPRAWN]

Well - you live and learn. Not that i ever knew a resistor plug existed or that i'm any the wiser for it. Glad you have it sorted though

Any plug with a "R" ... Eg NGK BPR7ES ..

[KINGPRAWN]

Back to rubbish again !!!!
Tried another Coil ... Same
Tried another TCI unit ... Same
Tried another plug cap ... Same
Tried no plug cap ... Same
Open circuit it sparks to ground .... Ground it out and ZERO spark ... How can this be ????

[Jim San]

Are you using the correct plug? BP7ES according to yam chart.
Have you changed anything else do to with the ignition system?
Have you charged the battery, is it in good condition.
Do you know anyone with the same bike you could try your parts on?

I've no idea really, these would be the questions I'd be asking myself

[KINGPRAWN]

Are you using the correct plug? BP7ES according to yam chart.
Have you changed anything else do to with the ignition system?
Have you charged the battery, is it in good condition.
Do you know anyone with the same bike you could try your parts on?

I've no idea really, these would be the questions I'd be asking myself

Thanks for the input .... All of those correct :/

[Jim San]

Open circuit it sparks to ground .... Ground it out and ZERO spark ... How can this be ????

Have I got this esra about face but could this be that there is just not enough ooomph getting to the plug? as if its being earthed or shorted out to something within the ignition circuit.

A chap at work has a similar bike but not 1000cc I think, if I get chance tomorrow i'll ask if he's hadany similar issues