GS750 Firing on 1 and 4 only

[formline]

I discovered today that a 750 I purchased is firing on 1 and 4 only. 2 and 3 fire from opposite coils. Does this mean that the coils are bad or could it be the boots and wires? The owner installed a Martek ignition when new. Could this be the problem? Any advice or experience with this problem would be appreciated. Thank you

[formline]

My Mistake

2 and 3 fire from the same coil. I suppose since both are out the chances of two bad plug wires are slim.

[BassCliff]

Hi,

Testing The Ignition System

See if that helps. Sounds like the right coil needs looking at. Does it have 12v? Is the ignitor working?


Thank you for your indulgence,

BassCliff

[Big T]

77 750?

Does it still have points?

Start there

[7981GS]

I discovered today that a 750 I purchased is firing on 1 and 4 only. 2 and 3 fire from opposite coils. Does this mean that the coils are bad or could it be the boots and wires? The owner installed a Martek ignition when new. Could this be the problem? Any advice or experience with this problem would be appreciated. Thank you

No points.

[850 Combat]

I would try switching the power to the left coil to the right and vice versa. Switch the 1/4 plug leads to 2/3. In my experience, that is possible.

If it changes to 2/3 running instead of 1/4, its coils. If it remains 1/4, it is the trigger/amp.

I assume its a Dyna on there? Are they Dyna coils too?

[formline]

Hello again, The bike has a Martek pointless ignition from the 70's and the coils are original. I'll try the coil swap today. Thanks for the input.

[7981GS]

If, he has one of these, it could be points:



Daniel

[Rudeman]

I had a Martek on my 77 750B and NEVER had a single issue with it. It's likely the coil.

[formline]

Hello again, I switched the coils and the coils work fine. The ignitor was mentioned earlier. Is the ignitor in the pointless unit? Are there two or does one ignitor fire both sides. If there is only one and it fires the left coil then shouldn't it fire the right coil? I've never worked with the pointless ignition. Maybe I should put the point system back on since it came with the bike or would it be better to pick up the Dyna system and install it. Thanks again for your replies.

[Defore]

Im having the same exact problem! but i have an 82 gs550l. only 1 and 4 are firing but im still trying to fix it? Ill continue watching this post. good luck.

[Rudeman]

Hello again, I switched the coils and the coils work fine. The ignitor was mentioned earlier. Is the ignitor in the pointless unit? Are there two or does one ignitor fire both sides. If there is only one and it fires the left coil then shouldn't it fire the right coil? I've never worked with the pointless ignition. Maybe I should put the point system back on since it came with the bike or would it be better to pick up the Dyna system and install it. Thanks again for your replies.

The pointless unit that fits under the ignition cover is just a triggering unit like the points. They are maintenance-free and never wear out.

I'd be sure to thoroughly diagnose the system before going out and spending a C-note or better on a Dyna S. Replace the Martek with the points and see if the problem goes away. If not then it's not the Martek but some other component inthe ignition system. Invest in a good service manual like a Haynes or a Clymer's and follow the guidance therein.

[Big T]

So, after you swapped the coil leads, 2-3 were firing?

If so, check the wire back to the Martek and see if there's a short or something

Then check the Martek to see if there's any wiring issues. It could be as simple as a bad connection. This type of ignition is pretty simple

Take off the ignition cover and show us what you've got under there

If it seems to be dead, get a Dyna S to replace it

[formline]

Hello again, Looking over the service manuals the 1977 with points didn't have a ignitor. That was added in 1980 with the pointless ignition. Since the bike was changed to pointless with the Martek system, is there a ignitor in the Martek system? Thanks again!

[Big T]

Hello again, Looking over the service manuals the 1977 with points didn't have a ignitor. That was added in 1980 with the pointless ignition. Since the bike was changed to pointless with the Martek system, is there a ignitor in the Martek system? Thanks again!

No ignitor in your system