Suggestions please, Black Spark Plug.

[Boney 0]

Today the 725 didnt want to start. Took plug out and it was as black as could be. It was also a thick black almost looked like black velvet. It does blow bluish smoke. Any suggestions about how I can help the problem until this summer. I will have motor out then and probly end up replacing piston. Thnx

[MPH 12]

I believe black plugs are a sign of running too rich, if it's just a flim,might try leanning carb some. Do you go through a lot of oil? Know on my B-112 I gotta add oil every tank of gas and the plug is normally fouled shut within 2 tanks with pretty dark crud. Soon as I get my floor poured out there it's coming apart.

[UCD 14]

Fuzzy black is a sign of to rich due to a vacume leak. Bad gaskets in carb, warn throttle shaft etc.

[firefoxz1 4]

Thick black would be from the oil it's burning. I never looked but see if they have a hotter plug that might keep some of that burned off and last a little longer.

[Boney 0]

Thnx all for the response. MPH when leaning the carb is that turn it in {clockwise} or turning it out {counterclockwise} ? I do go through a lot of oil. Maynard, thnx I will looki tomorrow and see if I can find some leaks.

[RayS 79]

Turn the needle in (clockwise).

[BLT 717]

quote:

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Originally posted by Boney
Today the 725 didnt want to start. Took plug out and it was as black as could be. It was also a thick black almost looked like black velvet. It does blow bluish smoke. Any suggestions about how I can help the problem until this summer. I will have motor out then and probly end up replacing piston. Thnx

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If you can chip it out with a small pic, it is most likely burnt oil. More spark plugs are the only way to stay ahead of it. Most all spark plug people frown on re-cleaning them as residue cleaning grit might still be present.

[firefoxz1 4]

Best way I have to cleaning plugs is to scrape and burn. After scraping most of the crud I burn the the rest off with a torch till the ceramic/porcelin? is glowing red. When it cools off if it is white again your usually good to go, just look for cracks. Don't worry if the ground electrode glows red also just regap if needed.

[MPH 12]

For the last two summers I just been taking the one from the B-112 to the soft wire brush on the bench grinder. Finish off with the grinder turned off twisting the plug into the brush. Seemed to run just as good and long as a new one, two tanks of gas.