81 gs 750 no fire

[tom203]

Unscrew spark plug caps from a coil; stick meter probes into wires and measure ohms; stock coils are about 12000 ohms wire to wire. Check both ignition coils. What do you have?
Nothing when you manually tried to trigger ignitor with screwdriver tip? doublecheck to make sure ignitor is being fed 12 volt positive thru its connector- this comes from those orang/white wires that feed both ignition coils 12 volt positive.

[shopguy]

will check with caps off but istill dont know why im getting 12 volt on both wires(orange/white from igniter and black/yellow from igniter to the same coil 2 and 3,other coil is 12 volt orange/white goes to on other wire white 1and4tried rotating pulse generator to see if it woul read change oncoils but it did not

[shopguy]

the sparkplug caps have certain amount of resistance is this correct i ohms tested them 3 of them same reading other copletely different

[tom203]

Yes, the caps themselves might have an ohm measure of 5000 to 10000 each depending on maker. Corrosion can make it hard to get a decent reading. The coils are easy to measure once you unscrew caps and measure wire to wire.

[shopguy]

alright done mr, m 1.5 test on igniter which is supposed to simulate pulse from pickup,had spark at plugs with this test.tried mr.m test on pikup by swipping thin screwdriver between contacts got nothing at all,so did first test prove that both igniter and coils are good and pickup is bad,did ohms on pickup got 324 tested my old igniter with 1.5 battery test and got no fire so it was bad,still stuck on coil that has power on both leads when you unhook at connector it is 12 volt orange wire plug it back in 12 volt both wires

[tom203]

I've done both the 1.5 volt battery test and the screwdriver flick on my bike and both sparked.
I was just looking at my Chilton's manual and the chain drive 650's use a different ignitor and signal generator setup than shafties- for the chain 650's Chilton talks about 80 ohm resistance across EACH signal coil to ground ( it still tests ignitor with 1.5 volt battery ) I'm unclear as to what resistance is correct. You need a 750 owner with same ignition to chime in.

The ignitor obviously needs to be triggered with enough juice or no sparky!

[shopguy]

ok im stumped short of just replacing everything i dont know what else to do

[tom203]

You know your old ignitor was no good (failed Mr. M's 1.5 battery test) but your replacement passes, yet it's not being triggered by signal coils which seem to test out ohm wise at 320. It would be nice if another 81 750 owner could verify that ohm reading of the signal coils.

[shopguy]

i was going by mr,m specsthat were 250-360ohms asi stated in previous post does this bike have kickstand switch which is no start when down

[tom203]

Nope, some bikes had kickstand switch that lit the oil light but it didn't kill ignition. I'd have to bet that this replaced ignitor is faulty- not feeding the signal coils with enough juice for them to "disturb" when rotor tab flies by.

I checked my spare signal coils- measured 315 ohms.

[shopguy]

probably going to put it back together and sell it tired of fighting with it anybody looking for 1981 gsxe750 with clear title

[almarconi]

Where are you located?

[shopguy]

Bell.fl 32619 $300.00