A fouled or bad spark plug is a plug that has become covered with a substance like oil, fuel or carbon or one that is blistered from running too hot. Other possibilities are the carburetor is adjusted too rich, or on a two-stroke outboard, when pouring too much oil in with the gasoline. The sun, the cool breeze off the water and the gentle rocking of the boat makes for a relaxing day. Signs that your boat’s spark plugs are failing include: To know for sure if a fouled or damaged spark plug is the cause of your boat’s engine issues, you’ll need to examine the spark plugs. it's one of the first signs of a sick engine. The other issue could be an incorrect gasoline/two cycle outboard oil mixture. When purchasing a two cycle outboard engine, it’s important to check customer reviews and even consult other boaters first. In this instance, a case of hard starting was the result of carbon buildup on the plugs. This will produce a weaker spark at the spark plug gap, making the engine harder to start. Whether you have a speed boat, pontoon boat or fishing boat, there is nothing like a day on the water. 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. Four Stroke Engines burn oil at startup mainly because of oil left in the cylinders or all the time with an oil leak. An Outboard Motor smokes because it is burning oil. Two-Stroke Engines burn oil all of the time. Their condition can also indicate lurking internal problems, too. With oil and gasoline covering the carbon that has adhered to the firing end, the insulation resistance value drops abruptly, causing misfires. ©2020 DRiV Incorporated. Step 2. Plugs are cheap. They are by far the easiest part to check first. A visual inspection of your boat engine's sparkplugs can help you diagnose problems. If this occurs a number of times after the spark plugs have been replaced, the engine is flooding with gasoline. Symptoms of Bad or Failing Spark Plugs. Engine is Misfiring. According to AA1Car.com, this occurs when the spark plug fails … The motor has been fouling out one of the two spark plugs. Spark plugs can foul up with oil and carbon on two stroke engines resulting in poor spark. Wet fouling is seen, for example, in motorcycles (with two-stroke engines). a fouled spark plug is when it isn't burning the fuel cleanly, usually leaving wet oilly deposits of the plug, thus causing it to misfire even more. A wet spark plug can indicate water in the fuel while a white residue on the plug can point to a plug that is too hot. For further recommendations, consult your owner’s manual or your trusted boat mechanic. In … 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. (some of the older units with the metal cased CD's read 8-14 ohms). Also, check the exhaust smoke. I foul the number 1 plug about every 5 or 6 trips. Actually 2, a F115 and a LF115. More serious issues are also plausible, for example, the choke or cold start enrichment circuit could be failing to switch on and off. If you can’t determine if it is carbon or oil fouling, smell the plug; it will smell like engine oil. If you’ve eliminated fuel problems and air problems, consider pulling each spark plug and giving it a thorough inspection. The length of time between spark plug changes depends on variables such as how many hours you use your boat and how you are using it. Fouled or damaged spark plugs can cause all sorts of problems in any engine, much less in an outboard. Next, check the spark plugs for signs of fouling. A carbon-fouled Spark plug looks like this Carbon-Fouled-Spark-Plugs. Need an idea of where to start. It ran great for the next 3 weeks. Take it from an old 2 stroke race bike guy and do yourself a favor. My 06' CR85 was fouling plugs one after another like crazy. Carbon fouling is one of the potential fouling problems that happens to spark plugs. Inspect the spark plugs for damage to the insulator tip, boot and upper and lower insulators. I just changed the fuel ratio to 40:1 instead of 32:1. A fouled spark plug occurs when the plug isn’t burning fuel normally, leaving damage to the plug which can cause the engine not to start. Driving with fouled or bad spark plugs can cause a host of problems for your engine. Gas is 32 times more than the amount of oil. Re: 15hp 2 Stroke Johnson Outboard Issues - Spark Plug Fouling Check your fuel in your tank, sounds to me like it might have copped a bit of odd fuel (diesel or similar) by mistake sometime. This spark plug lead connects to the secondary circuit, which sends an electrical charge from a coil to the spark plug. If the engine requires actual maintenance, it can become expensive fast. The top spark plug is dry and kind of a grayish/tan color and the bottom one is wet an a little darker when I pull them out. If the spark plugs show signs of damage or fouling, new ones may be in order. | ' : ''}}{{lede.tags.join(', ')}}. Now it is starting to hesitate when mashing the throttle to get up on plane after trolling it for 6 hours. Tis the season for tune-ups, my friends! Next, check the spark plugs for signs of fouling. Before you know it, your boat engine starts acting up and your day of fun is over. One of the most common issues with two cycle outboard motors occurs when the spark plugs become saturated with gasoline, and foul out. Sooting can occur which can ruin your boat’s engine. If I clean the plugs they run again for same amount of time, clean, repeat. We encourage you to consult with a certified technician or mechanic if you have specific questions or concerns relating to any of the topics covered herein. So, what are some of the common causes of flooded boat motors? Choosing the Right Two-Cycle Outboard Oil for Your New Boat, Yamaha Oil has a History of Quality Performance. All 8 plugs black fouled, dry, no oil. Spark plugs are a popular item to change, and it is important to know what a good spark plug vs. a bad one looks like.There are tons of different types of spark plugs (iridium, platinum, standard, pre-gapped, 4 grounded etc.,) but there still are some telltale visual signs that tell you of a bad spark plug (or a poorly running cylinder). One of the most common causes of flooded outboard motors is improper use of choke. Buy two sets at a time and keep a set in the boat. According to NGK Spark Plugs, when the insulator nose of the spark plug is coated, it is considered fouled. If enough oil is in the combustion chamber, the deposits can build up on the tip, porcelain or shell. Spark plugs that are continuously fouling can indicate a weak spark. If this occurs a number of times after the spark plugs have been replaced, the engine is flooding with gasoline. The engine ran great the first few times I had it out, but always seemed sluggish, I was getting 4600 rpm and 36 mph at WOT, but it would take a while to get up there, it didn't seem to be very responsive. 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. 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. When it seems like no amount of replacement plugs can fix the issue, it might be due to a number of factors. Listed below are a few common symptoms of worn out spark plugs or spark plugs that have fouled and need ... 2… My 1995 Mercury 3 cylinder 2 stroke 60 HP is fouling plugs regularly. for factory 125cc 2 strokes and 250cc 2 strokes for people that are having problems fowling plugs in summer time trail riding or even in the sand dunes See Photo 2. Done this 3 times now and need to figure out what might be causing this and what I … Once that porcelain gets soaked, it's toast. A fouled spark plug occurs when the plug isn’t burning fuel normally, leaving damage to the plug which can cause the engine not to start. If the coil is weak or damaged it will produce less spark energy than it is designed to. Replace the plug good for more 5 or 6 more trips. However, under load, the fouled plug will misfire, resulting in "blow-by" of fuel mixture, eventuating crankcase contamination with fuel (assuming a 4-stroke engine). So, you have some work ahead of you to determine why you keep fouling the spark plug in your 2-stroke dirt bike. A key component of your boat’s engine, marine spark plugs take in high voltage electricity at one end and ignite a spark at the other end. When there’s an imbalance of these elements, the motor may fuel with an excess amount of fuel. 10. To read a spark plug and assess engine troubles, you first have to remove it. Oil fouling of a spark plug typically results in a shiny, black appearance. {{lede.date | date:'dd-MMM-yyyy'}}{{lede.tags.length > 0 && lede.date ? ' Disconnect the boat’s spark plug lead from the spark plug. Photo 1: Dry fouling Photo 2: Wet fouling Schematic drawing: 2) Under no circumstances will we be liable for any loss or damage caused by your reliance on any content. If a bad spark plug remains in your engine for the long period of time, the effects can be devastating to your engine. Weak spark could also be the culprit. Engine Misfires. I think fouling plugs has something to do with excess oil drowning out the plug. After a long storage, both motors were fouling plugs. HOW TO PERFORM 100-HOUR SERVICE ON A 2-STROKE MERCURY OUTBOARD STEP TWO: Spark Plugs & Compression T his step begins by removing any plastic covers covering your spark plugs or ignition coils. A normal spark plug will appear dry with a grayish color. Oil Fouling. I've had guys tell me 100 times that they "just bought those plugs"...when I told them to toss em out. Such a plug can reportedly be decontaminated with a torch, although a more direct fix is a simple replacement of the affected plug. The content contained in this article is for entertainment and informational purposes only and should not be used in lieu of seeking professional advice from a certified technician or mechanic. A normal spark plug will appear dry with a grayish color. Worn or damaged pistons leak oil which fouls the spark plugs. You launch your boat and begin to cruise. Step 3 Also, when I was running 32:1, there was oil dripping out my exhaust and making a mess. They have the correct spark plugs per the owner's manual. Like many automotive components, spark plugs don't last forever. The plug on the left is fouled with carbon. For example, it means that for every 128 ounces (one gallon) of gas, you add 4 ounces of 2-stroke oil for a 32:1 ratio, or just over 3 ounces to a gallon for a 40:1 ratio. For most 2-stroke motocross bikes, a good ratio is 32:1. Instant carbonisation sort of points to either excessive oils in the fuel or too cold a plug. Privacy Policy | Ad Choices | Terms of Use | See official rules for restrictions and complete contest details. If the engine misfires, it's typically due to an issue in the ignition system. Choke. You don’t want to test your outboard coil with these wires connected. The website continues to explain that while carbon fouling can cause problems, if … ... hour after hour after hour. There are a couple of tricks that can be done to reduce the amount of smoke that an engine burns and here are your best options! I just had the carbs rebuilt and tuned and the motor still fouls out one plug and only runs on one cylinder. My dealer replaced the plugs, they were really fouled up. All rights reserved. A fouled spark plug occurs when the plug isn’t burning fuel normally, leaving damage to the plug which can cause the engine not to start. Could it be the spark plugs? The motor is set up for full synthetic and I only run XD 100 oil, I have been running super unleaded in it since the new plugs with the 2+4 additives. You get your boat off the water and begin to troubleshoot what could have gone wrong with the engine. If the plug is black with soot, it can mean that the fuel has too much oil while an eroded plug can indicate a too-hot plug. Learn more about Champion spark plugs for boats, find your boat part, or find where to buy your boat part today. While engine misfires can trigger check engine lights, they don’t always trigger … Use a spark plug wrench with an extender. Both motors doing exactly the same thing. When a vehicle engine is reluctant to start, it often means that the spark plugs need changing. A common malfunction is a wet spark plug. To the point that they would start to miss after about 45 minutes of cruise running, 4000-4500 rpm's. That spark fires the air and fuel mixture within the engine and creates the combustion that powers your boat. Once you get the socket over the spark plug, place your hand over the head of the wrench, grasping the head firmly and pull the handle, hitting it … As a result, starting the engine may prove difficult due to the wet spark plugs. A too rich air/fuel mixture is a great way to ruin a spark plug. If one or more cylinders will not fire with the spark plug installed], check the timer base resistance between sensor leads: PP2, from white/black to black/white; PP3 from black/white to all all whit/blacks; PP4 1-3 and 2-4, readings should be 10-20 ohms for all sensor coils. The oil … can be from bad carboration, spark, carbon, compression, misadjusted gap, just to name a few. Compare it to the new plug on the right. Dont try to clean plugs on a 2 stroke. A wet spark plug can indicate water in the fuel while a white residue on the plug can point to a plug that is too hot. I have a 1984 Mercury 25HP XD outboard. A normal spark plug will appear dry with a grayish color. An easy fix, for a few dollars you can get your boat engine running again. I have a question for you guys about a boat I recently purchased, a 2002 Boston Whaler, with a 2003 Yamaha 90hp 2 stroke Outboard. This voltage gets transported to the spark plugs, where it fires up the engine.