suddenly, no spark

[rlevenson]

80 550 L, will not start, had been running excellent and starting right up every time

this morning I had tank off, it is back on the bike with fuel supply and vacuum lines reattached

battery fully charged
fuses intact
on pressing start button, strong steady starter motor cranking
all lights are working
plenty of gas

cranks and cranks, will not start

Removed spark plugs one by one; reattached plug wire and on cranking touched the tip of plug to engine, no spark on any of the four plugs

I have a multitester and the wiring diagram, but am kindergarten with these things. Rudimentary visual check does not show anything obviously disconnected, fried, melted or loose. This bike so far had not given signs of electrical glitches.

What are steps for locating the fault ?

Thanks for the leads.

Sincerely,

Richard

[KEITH KRAUSE]

Not sure how your model is wired but try a new ignition fuse. Don't just trust the existing fuse because it may look good. Check any solder points in that area too.
If good,try checking the ignitor connections. Maybe a loose connection.

[tconroy]

80 550 L, will not start, had been running excellent and starting right up every time

this morning I had tank off, it is back on the bike with fuel supply and vacuum lines reattached

battery fully charged
fuses intact
on pressing start button, strong steady starter motor cranking
all lights are working
plenty of gas

cranks and cranks, will not start

Removed spark plugs one by one; reattached plug wire and on cranking touched the tip of plug to engine, no spark on any of the four plugs

I have a multitester and the wiring diagram, but am kindergarten with these things. Rudimentary visual check does not show anything obviously disconnected, fried, melted or loose. This bike so far had not given signs of electrical glitches.

What are steps for locating the fault ?

Thanks for the leads.

Sincerely,

Richard

Have you checked the coils where they plug in to the harness.Clean the contacts on the coils and see if you get spark before you put the tank back on.If it was running great before you took the tank off then something must have happend when you put the tank back on .Possibly pulled a wire loose or something.

[rlevenson]

still looking, what/where is "ignitor"

I am looking at everything that might be loose or dirty, and cleaning, put in 10a fuse in the "ignition" slot in the fuse box. Are there any hidden "in line" fuses ?

The term ignitor in Keith's post, that would not mean the two cylindrical boxes that send high tension juice to the spark plugs, those are "ignition coils " in the manual ? I am not finding in the book anything specifically called ignitor.

Thanks again.

[brveagle]

I am looking at everything that might be loose or dirty, and cleaning, put in 10a fuse in the "ignition" slot in the fuse box. Are there any hidden "in line" fuses ?

The term ignitor in Keith's post, that would not mean the two cylindrical boxes that send high tension juice to the spark plugs, those are "ignition coils " in the manual ? I am not finding in the book anything specifically called ignitor.
Thanks again.

I am 95% positive that's what it is... Check under the airbox.. That's where mine was on my gs550's... Just follow the wires, it's usually cleverly hidden

[tconroy]

I am looking at everything that might be loose or dirty, and cleaning, put in 10a fuse in the "ignition" slot in the fuse box. Are there any hidden "in line" fuses ?

The term ignitor in Keith's post, that would not mean the two cylindrical boxes that send high tension juice to the spark plugs, those are "ignition coils " in the manual ? I am not finding in the book anything specifically called ignitor.

Thanks again.

It should tell you in your manual.Look under reg/rec.section and you will find it.It is probably under you air box.They like to tuck them away like that.You should be able to see it from the right side close to the bottom of the battery box.

[matbrodog]

Follow the cable from the ignition on the bottom right sid of the engine and it will lead direct to the ignitor /CDI box,Check the box connectors into and out of the box as it sounds as if Keith is spot on with his diagnosis.