Plug fouling question???

[DR.DUCK2000]

I have a 2-stroke Johnson 25. It is great on my 15 ft boat. I always carry extra plugs and a plug wrench...because one time I had the plugs foul and that was a very long ride having to idle all the way back to the landing...My question is for some of you that have more knowledge than I about these motors. Did the plugs foul b/c I idled around to much going slow or improper fuel mixture? I have heard both will cause it. I now have two tanks and keep a constant mix in each. Just wondering if there is any other things that I can do to prevent that from happening again. I did learn my lesson though and keep those extras with me. Thanks for any input. [img]images/smiles/icon_confused.gif[/img]

[NOHERE]

you will get an oil build up on the plug, this can and does cause fouling...another cause is improper sparking, this is from various reasons. by simply "running" the engine at a higher rpm for , say , 10 to 15 mins should take care of the situation if you have been idling quite a bit during the day. another little trick, every 3-4 times you use the motor....take the plug or plugs out and simply wipe the end of the plug off with a clean wrag dipped in gas.

[Po Monkey Lounger]

Plugs fouling is most often caused by improper fuel mixture. Find out your manufacturer's suggested gas/oil ratio and be as precise and consistent as possible when mixing---using good quality synthetic oil and good quality gas (bad gas will screw up your hunt). This does not guarantee you will not foul a plug, but it makes it a rare occurence. Since extra plugs and a plug wrench take up so little room in the boat, there is no excuse for letting a fouled plug ruin a hunting trip.

[CaptnT]

DR.DUCK2000, I wonder what grade of gas do you burn? I have learned over the years different motors prefer different grades of gas. I had a honda that refused to run on smooth on anything but premium. A Johnny-Rude that preffered mid-grade, and now my Yamaha runs best on the plain old 87 octane unleaded. I think its because I'm not a hot rodder on the water, only opening it up when I need to. Try different grades of gas as well as the other good suggestions given here.

When is the last time you changed the fuel filter?

[no angel]

it could be something in the carb doing it also a busted diaphram in the carb will let gas constantly run. the best thing to do is go get it checked by a boat tech because it should not foul plugs from idleing around. i haven't ever seen a 4 wheeler or car foul plugs unless fuel was just pouring in it . it is more than likely the carb but it be too much oil in the mix also. most are 50 -1 ratio but the plug gap could be closed not letting enough fire through to the chamber. there are 1 million it could be's but a person that fools with these regularly can spot it right off the bat.

[DR.DUCK2000]

Thanks for the info guys. It only happened once last fall during some preseason scouting. While hunting this year it did great...I was meticulous on my fuel mixture and kept a wrench and plugs in my gun box. Just wanted to make sure there wasn't anything else. Thanks [img]images/smiles/icon_biggrin.gif[/img]