HELP!! 1981 gs1000l no spark

[foxxx85]

I have a 1981 GS1000 L. It ran just fine in March. Charge the battery and fire right up. It was ridden for only a day or two at that time. It has sat ever since. Recently brought it back out, changed the oil, charged the battery.... No start. It cranks and cranks but won't start. I checked for spark by pulling the plug and holding it just off the engine( still connected to plug wire) but there is no arc. Can anyone help direct me?

[psyguy]

maybe a bad kill switch

see if you get any voltage at the coils

[foxxx85]

I will check voltage on thursday... i am out of town until then. what should the voltage read? Thank you

[psyguy]

the voltage at the coils should be very close to what you get at the battery, 12V would be good, however the spark would be produced at less than that

btw, when checking for spark, you want to have the sparkplug touching the engine

if the petrol is 6 months old, that may be a problem too

[foxxx85]

I checked for spark again... none. I checked the voltage going to the coil by disconnecting the clip that goes to each and checking the voltage in the clip and got 12.2. ....?

[Thelen82gs550l]

I dont think that it would be the kill switch because if mine is in the stop position it wont even turn over

[foxxx85]

Good Call!! i just tried to turn it over in the OFF position and it wouldn't crank... Anyone have any advice? Where to now...

[foxxx85]

How do i check voltage at the plug wires and what should it be?

[psyguy]

I dont think that it would be the kill switch because if mine is in the stop position it wont even turn over

a "bad" kill switch is where you can crank the engine as the starter motor relay gets the power from the "start" button but the coils dont get any power as the kill switch isn't functioning properly


it is unlikely that both coils would fail at the same time however it pays to test them
the igniter is a suspect too

download a manual from bikecliff website for the testing procedure

[foxxx85]

how do i bypass the kill switch... just to totally eliminate it from the equation. Sorry for the simple questions this is my first bike project.

[psyguy]

if you re getting the power to the coils and can crank the engine, the kill switch is ok, so no need to bypass it

one other thing to check is the sparkplug caps
and make sure the caps have a good contact with the coil leads

[foxxx85]

get no spark if i ground the plug to the head. If i take the plug cap(boot) off and touch the wire to the head i get a spark. If i put the boot back on the wire and put a jumper to the contact in the boot i get a little spark. Put the plug in the boot and i get no spark. Spark plugs have been tested in another bike and they fire fine. I am doing this all by using jumper cables to a good battery. Would the jumpers cause the weakness??? Is it the plug wire/boot?? All four to fail at once would just seem odd. Also, The way i checked voltage going to the coil was to disconnect the clip that has and orange and black wire going to each coil and put my meter inside that clip and got 12.2 volts. is this correct or should i be checking somehow what comes out of the coil.

[psyguy]

yes you used the right way to check the voltage at the coils
if the sparkplug caps are old it pays to change them, they are often a culprit for a bad running engine
cut the coil leads 1cm back to expose good wire to connect to the new caps
also, given your symptoms, maybe the caps dont connect well to the sparkplugs - another warrant to get the new caps

[foxxx85]

I dont know what caps to purchase. i am looking at Z1... I am pretty sure i need 2 of the small 120 degree and 2 of the larger 120 degree 14mm thread. Are these the correct ones?? I dont know how to determine if they are the right ones for my bike. 1981 1000gl I am going to get new plug caps and a new battery. Hopefully this will help.

[foxxx85]

I bought a new battery and trimmed my wires and i have great spark now. I still can't get the bike to fire up though. Thank you for your help getting spark psyguy. Hopefully i can get this bike going before the season ends.
Cheers!