8n running rough

I replaced the points/condenser/rotor button this week. I had replaced the dist. cap and plugs(Champion H10) and plug wires this past summer. I noticed this problem after that, and discovered a plug wire was arcing against the engine head. I moved the wires, and the problem went away. I cant get it to go away now.

I swapped a friends carburetor on it to see if it could be a fuel problem, but still noticed no change.

What do you think would be the next thing to do?

I get nervous when guys say they changed their ignition wiring and now it don't run well.

Check your firing order, should be 1,2,4,3 CCW. That N-Engine is so GOOD, that it'll start and run (not well) miss-wired. Generally, its the 3 & 4 sparkies that getts miss-wired..... .....respectfully, Dell

Engines need three things to run correctly:

1) Good spark (whitiesh/blue) delivered to each cylinder at the propert time

2) Proper fuel/air mixture delivered to each clyinder

3) Sufficient compression.

Assuming your tune-up was indeed thorough AND YOU HAVE whitiesh/blue spark, then turn attention to each of the three fuel screens in case they are gummed up. If all three okay, check for manifold leaks (not uncommon for a manifold gasket leak or burn-thru between exhaust and intake to develop).

If above okay, then eithe your and your friend's carb need adjustment or rebuilding OR your compression is poor in one or more cylinders. Could be anything from a stuck valve(s) to broken rings to head gasket, etc...

However, I'm guessing your tune-up was not complete. Replacing parts and regapping to specs is NORMALLY sufficient, but many other things can cause poor spark. For example, the little gounding strap and the insulator in your distributor can cause very poor performance (or none at all) or your starter or kill switch has an intermittent ground. MAKE SURE you have good spark or diagnosing from there can be a real pain...

2) 1" or so cylindrical screen that sits inside the top of the assembly itself and protrudes into the tank itself.

3) 1" or so cylindrical screen that goes in the elbow fitting that connects fuel line to carb.

From your reply to Dell I have to wonder about your decision to swap the wire order. You should only have to look at where each plug wire is attached to the distributor cap and trace it to the appropriate spark plug. NO NEED to swap anything unless your visual inspection shows you have the firing order (1-2-4-3) incorrect. Random swapping is not necessary.

As for the quality of spark question, take an old properly gapped plug if you have one and pull #2 or #3 plug wire. Atach it to the old plug and make sure the end of the plug is grounded. Crank engine and look at the spark. If whitiesh/blue it is good. If yellow or non existent, then probably your point gap is bad or perhaps coil/condensor.

AGAIN, you must check the integrity of the little grounding strap inside your distributor AND the insulator that runs thru the distributor. These can be gounding and that will dengrade/eliminate spark. So will a bad rotor.

Thank you very much for your help.

Once you know the condition of the plugs.. that will give you some clue to the problem.. i'e' oil on plugs, sooty plugs, coolant on plugs.. etc.

Also.. check the condition of the spark at each plug when you crank over.

Did you use nice copper core wires.. the carbon fiber anti radio static wires don't work well on our LEI systems.. ;-)

Go through all the steps.. inspect the rotor and cap.. look for burns / corrosion, as well as any indication of the rotor striking the cap ( ecentric motion caused by worn parts in the distribuitor). Also look over the insulators in the distribuitor side where the wire exits.. check for arcing there.

And check your fireing order.. 1243.. reversing 4 and 3 will kill power but allow starting.. etc.

Check your coil and all electrical connections.. If the coil is old.. might get a new one...and keep the old one as a backup .. etc.

good luck

report back what you find.

Soundguy

I'll try the hotter plugs and run the thing in the dark to help find arcing.

the coil may be old - I never replaced it.