What do fouled plugs look like

[whalerjet]

I am familiar with what a fouled plug looks like in a car engine because it is not supposed to burn oil, but what does a fouled sparkplug look like on a 2 stroke engine? <br /><br />Is anyone familiar with the wiring on a COBIA boat? I removed my faria tachometer and now need to reinstall it. I misplaced (lost) my diagram of the wiring connections. I have three posts that need the loose wires. There are two black wires, two purple ones and a single gray wire. I feel certain the black goes to ground, but which goes to signal/sender and battery? Also, what is the pulse setting for this tach? I have it set at 6 which works better than the 5 that it was set at factory. The motor is a Yamaha 150 1998 without oil injection if that matters. Whenever I trim the motor the tach will respond with what I call a crazy needle and then return to where it seems it should be.

 

[Spidybot]

Re: What do fouled plugs look like

Fouling is any kind of deposits on the spark plug tip. The fouling can tell about malfunctions in ingition/fuel depending on how it looks. A motor that burns the fuel optimally will have no or very little deposits. Some fouling can be OK if you know it stems from the way you've used the motor (extensive idling, enriched fuel/air mix, use of choke, low oil/fuel quality).<br /><br />Fouling can look wet or dry but should, after running at normal working rpms, be very little.