Having ignition trouble need help.

[gsryder]

Okay I am having some serious problems here. I will try to walk thru this as detailed as possible. I have a 81 GS750. The bike ran great just gave me problems with cold starts, after it was started and warm it would run great and start every time. So I was reading about the relay mod thinking this would help. This where I have been having problems.

I did / wired something wrong on the first attempt

Now I have spark from the left coil - cyl 1 and 4

No spark from right coil - cyl 2 and 3

Bought used set of coils from ebay replaced all wiring back to stock

Same problem.

Have voltage to both coils (10 to 11 volts) and voltage leaving both coils.

Still no spark on cyl 2 and 3

I then swapped out the left coil for the right coil still no spark.

Replaced left coil and I have spark again.

I am convinced it is not a coil problem.

Is there a way to test what is actually wrong with this.
My next guess is the pick up coils (if that is the right name?) on the right hand side of the motor in front of the clutch.

Need help...............................

[Dave8338]

Okay I am having some serious problems here. I will try to walk thru this as detailed as possible. I have a 81 GS750. The bike ran great just gave me problems with cold starts, after it was started and warm it would run great and start every time. So I was reading about the relay mod thinking this would help. This where I have been having problems.

I did / wired something wrong on the first attempt

Now I have spark from the left coil - cyl 1 and 4

No spark from right coil - cyl 2 and 3

Bought used set of coils from ebay replaced all wiring back to stock

Same problem.

Have voltage to both coils (10 to 11 volts) and voltage leaving both coils.

Still no spark on cyl 2 and 3

I then swapped out the left coil for the right coil still no spark.

Replaced left coil and I have spark again.

I am convinced it is not a coil problem.

Is there a way to test what is actually wrong with this.
My next guess is the pick up coils (if that is the right name?) on the right hand side of the motor in front of the clutch.

Need help...............................

So am I... It sounds like an issue with wiring or the igniter. Someone with much more experience in the ignition systems will chime in soon...

[Nessism]

Your service manual should have an ignitor check. That's next thing on the list.

[gsryder]

Does anyone have a down loadable version of the manual or know where to get one?

[Dave8338]

Check with Basscliff or on his website...

[gsryder]

Thanks for the help guys. Also does any one know if the ignition pick up coils are the same for 650, 750, 850, 1100? Or if any are interchangeable?

[salty_monk]

It's more likely to be the ignitor box that's had it rather than the pick-ups themselves. The tests are simple enough.

Your best bet is to get a Dyna S ignition set for $120 & wire it up if there are any issues with either. It's cheaper & simpler. Make sure you wire it in properly.

Dan