1986 odd running problem

[dieselcowboy]

Hi fellas, My 86' Marathon is giving me fits. Just about in desperation to find the problem.
Its been in our family at least 20 years. My dad was running it and it just quit on him. I got ahold of it and found no spark so first thing I did was Print a manual on it.
Long story short I have it running but not very well. It idles ok but as soon as the gas pedal is pushed past the brake pedal level it starts backfiring and loosing rpm / power. Does this in forward and reverse.
Here is what I have done to the cart because of this....

Honed cyl and installed new piston, gaskets on top end (piston was scored and blown head gasket)
Replaced crank seals
New fuel pump and carb
New coil
New pulsar
New spark plug
Cleared fuel lines
Removed muffler and cleaned inside and out.
Adjusted everything by the book except for the timing. Its still where is has been for the whole time we owned it. Checked over wiring about 100 times.
Have not replaced ignitor or voltage regulator. I am very familiar with mechanics and just can not for the life figure this one out. Any help is surly appreciated guys.

[trig123]

Originally Posted by dieselcowboy

Hi fellas, My 86' Marathon is giving me fits. Just about in desperation to find the problem.
Its been in our family at least 20 years. My dad was running it and it just quit on him. I got ahold of it and found no spark so first thing I did was Print a manual on it.
Long story short I have it running but not very well. It idles ok but as soon as the gas pedal is pushed past the brake pedal level it starts backfiring and loosing rpm / power. Does this in forward and reverse.
Here is what I have done to the cart because of this....

Honed cyl and installed new piston, gaskets on top end (piston was scored and blown head gasket)
Replaced crank seals
New fuel pump and carb
New coil
New pulsar
New spark plug
Cleared fuel lines
Removed muffler and cleaned inside and out.
Adjusted everything by the book except for the timing. Its still where is has been for the whole time we owned it. Checked over wiring about 100 times.
Have not replaced ignitor or voltage regulator. I am very familiar with mechanics and just can not for the life figure this one out. Any help is surly appreciated guys.

These engines don't idle. Make sure your piston is in correct. Remove exhaust and look in cylinder. If you see the rectangle hole in piston you have it in wrong.
Make sure you have the pulser coil wired correct also. If wrong it throws the timing out and won't run.

[dieselcowboy]

I know I've got the piston in correctly. Eureka on the pulsar wiring. I put it back just as the old one came out and never thought any more about it. Going to swap red and blue wires and see if that helps. I know it works on the HEI deal. Maybe it will work here also.

[dieselcowboy]

Most of these don't get followed up on. Swapping pulser wires fixed the problem. No more backfire and back up to running great.

[crash12888]

Thanks, we do appreciate the follow ups from people.
Some ya just never hear from again.....

[Dabble Inn]

Just read this thread, glad you got it running and yeah Thanks for the follow up. We like the winning success stories

[trig123]

Originally Posted by dieselcowboy

Most of these don't get followed up on. Swapping pulser wires fixed the problem. No more backfire and back up to running great.

Always glad to hear good news. Thanks for letting us know.