Reasons for Fouled Spark Plugs

One of the most common issues with two cycle outboard motors occurs when the spark plugs become saturated with gasoline, and foul out. When it seems like no amount of replacement plugs can fix the issue, it might be due to a number of factors. Most often fouled spark plugs are noticed when the engine starts fine, runs fine for a while, but then bogs down, starts to lose RPM, and dies. If this occurs a number of times after the spark plugs have been replaced, the engine is flooding with gasoline.

The most common cause of this issue can be attributed to incorrect spark plugs, so be sure to check that the right spark plugs are being used first. The other issue could be an incorrect gasoline/two cycle outboard oil mixture. More serious issues are also plausible, for example, the choke or cold start enrichment circuit could be failing to switch on and off. If the engine requires actual maintenance, it can become expensive fast. When purchasing a two cycle outboard engine, it’s important to check customer reviews and even consult other boaters first. Two cycle outboards from brands like Yamaha, Mercury, and Evinrude have proven track records of success, while other brands might not enjoy much in terms of industry respect.