Fouled plugs

[birch]

It seems I have been reading alot about fouled plugs and cold pipes in the forum lately. Here's a trick that might save some money. My friend told me about this trick he used on his XS when he was having carb problems.

Spray the inside of the plug out with any brand of carb cleaner. Stick the red squirter stick up there and let er' have it. Wait a minute or two and then spray again. After that, get the spray wand into your air compressor and evaporate the carb cleaner out of the sparkplug. Repeat the process again, and they will fire like new.

[TADracer]

True. It works but.....you still must solve the problem that caused the fouled plug in the first place.

If everything is right then all four should be burning a nice light tan on the insulator. And it will take a ride of at least a few miles to re-color your plugs after you make a tuning change.

[birch]

Absolutly.

However, I know there has to be at least a few snowmoblile riders out there that just throw them away when they figure a plug is fouled. All those suckers were me in the past. I used to leave a trail of plugs to find my way home until i learned this trick.

[dbeardslee]

Birch - I just clean mine with a little wire brush - looks like a wire toothbrush. I just blow on 'em to get rid of the loose stuff, put 'em back in, and they work fine. Mine was giving me fits 'till I rebuilt the head so I started carrying a brush in my tool kit. If I got someplace and it didn't want to start I would just take 'em out, clean 'em, and it would start right up.

[Flatlander]

please explain

I know what happens when a plug foules.......It don't work!
But can someone explain what is happening insde the plug actually?

[DiverRay]

In simple terms....
A spark plug works by having a high voltage "jump" a gap between the center electrode and a ground. When a plug is "fouled", there is a path the electricity can follow between the center electrode and the ground without "jumping" the gap. This can be liquid as in gas or oil, or solid as in carbon or other deposits.
HTH

[HobbyMan]

I use carb cleaner and a wire brush. Regap and reinstall. I replace them every once in a while.

[dbeardslee]

Flat - what Ray said. It's the outside of the plug that gets fouled, not the inside.

[TADracer]

What everyone is saying is true but if your plugs foul in a 4-stroke motor then there is a problem that must be cured.

The reason a plug fouls is because the combustion chamber temperature is too low to burn off the carbon and deposits. Too much fuel, bad rings or valve guides passing oil, weak spark, poor fuel and other things can all cause the chamber temp to go below the 1,200 +/- degrees it takes for proper combustion.

When you have a good tune and the chamber temp is where it is supposed to be your insulators will color a light tan and you will never have the need to clean your plugs because of fouling.

[birch]

I havent had to clean my plugs since I fired her up for the summer (over 2000 miles ago). She loads up if I let er Idle for over five minutes, but cleans up again once I twist the throttle. Still, every spring I always foul at least one plug on the initial start up.

Everyone should take the time to get their bike functioning properly. Hot spark and good fuel/air ratios are a must. The time inbetween when one might be tempted to tear his/her hair out might be well spent doing some self preservation by saving some money and time to the parts store.