View Full Version : Fouled plugs?
Black Dog
10-03-2001, 10:20 AM
My F80 runs a bit rough above idle (prop engaged). It is sweet and smooth everywheere else.
Do I have a fouled plug?
How do I check for a fouled plug?
I have been running Stabil regularly.
Woof!
perchjerker
10-03-2001, 11:05 AM
Is the motor an O/B?
All you have to do is pull the plugs and look at them. Most of the time, a fouled plug will be either black and oily (oil fouled) or sooty or wet with gas (gas fouled). If they all look that way, best to change them anyway. You can try to clean them, but its not really recommended. (the insulation breaks down and causes them to short out).
There is a chance the breather tube that comes out of the head and into the silencer mounted to the carbs is drawing oil. The oil will collect in the bottom of the silencer and get sucked into the bottom carb causing a rough idle. I only say this because it happened to me. I removed the silencer, cleaned the oil out of it and the carb, and drained 1/4 quart of oil out of the reservior to eliminate it from happening again. I wish these motors used a pcv valve type baffle in the head where the breather tube feeds out.
buzzer IA
10-03-2001, 01:57 PM
Hey Back Dog,
I wondered the same thing before I headed for Canada this spring, so I pulled the plugs from my Mariner and took them to the best outboard wrench in town and asked him if he thought they were worn..He asked if I "float tested" them yet..As you can imagine, I had a dumb look on my face when I asked him what the float test was..He laughed and said, "Take the plugs down to the river and throw them in..If they float, they're still good!!Otherwise, spend $2.50 each and get a new set of NGK's and your problems will be solved.."
Well, they didn't float (LOL) and I bought a new set of plugs..Problem solved!!
Hope that this helps!!
buzzer IA