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. Actually 2, a F115 and a LF115. 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. Listed below are a few common symptoms of worn out spark plugs or spark plugs that have fouled and need ... 2… Driving with fouled or bad spark plugs can cause a host of problems for your engine. That spark fires the air and fuel mixture within the engine and creates the combustion that powers your boat. Now it is starting to hesitate when mashing the throttle to get up on plane after trolling it for 6 hours. My 06' CR85 was fouling plugs one after another like crazy. This will produce a weaker spark at the spark plug gap, making the engine harder to start. 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. Fouled or damaged spark plugs can cause all sorts of problems in any engine, much less in an outboard. So, you have some work ahead of you to determine why you keep fouling the spark plug in your 2-stroke dirt bike. It ran great for the next 3 weeks. Sooting can occur which can ruin your boat’s engine. Four Stroke Engines burn oil at startup mainly because of oil left in the cylinders or all the time with an oil leak. The motor has been fouling out one of the two spark plugs. (some of the older units with the metal cased CD's read 8-14 ohms). If enough oil is in the combustion chamber, the deposits can build up on the tip, porcelain or shell. 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! Worn or damaged pistons leak oil which fouls the spark plugs. can be from bad carboration, spark, carbon, compression, misadjusted gap, just to name a few. My 1995 Mercury 3 cylinder 2 stroke 60 HP is fouling plugs regularly. Step 3 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. For further recommendations, consult your owner’s manual or your trusted boat mechanic. In … Step 2. Symptoms of Bad or Failing Spark Plugs. Once that porcelain gets soaked, it's toast. Also, when I was running 32:1, there was oil dripping out my exhaust and making a mess. Under no circumstances will we be liable for any loss or damage caused by your reliance on any content. With oil and gasoline covering the carbon that has adhered to the firing end, the insulation resistance value drops abruptly, causing misfires. If you’ve eliminated fuel problems and air problems, consider pulling each spark plug and giving it a thorough inspection. They have the correct spark plugs per the owner's manual. 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. Choosing the Right Two-Cycle Outboard Oil for Your New Boat, Yamaha Oil has a History of Quality Performance. 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. 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. Use a spark plug wrench with an extender. If this occurs a number of times after the spark plugs have been replaced, the engine is flooding with gasoline. I foul the number 1 plug about every 5 or 6 trips. 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. The plug on the left is fouled with carbon. I think fouling plugs has something to do with excess oil drowning out the plug. 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. This spark plug lead connects to the secondary circuit, which sends an electrical charge from a coil to the spark plug. When it seems like no amount of replacement plugs can fix the issue, it might be due to a number of factors. If I clean the plugs they run again for same amount of time, clean, repeat. Gas is 32 times more than the amount of oil. 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. 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. The other issue could be an incorrect gasoline/two cycle outboard oil mixture. Plugs are cheap. Dont try to clean plugs on a 2 stroke. An Outboard Motor smokes because it is burning oil. Weak spark could also be the culprit. {{lede.date | date:'dd-MMM-yyyy'}}{{lede.tags.length > 0 && lede.date ? ' The website continues to explain that while carbon fouling can cause problems, if … Photo 1: Dry fouling Photo 2: Wet fouling Schematic drawing: 2) A carbon-fouled Spark plug looks like this Carbon-Fouled-Spark-Plugs. I just had the carbs rebuilt and tuned and the motor still fouls out one plug and only runs on one cylinder. If a bad spark plug remains in your engine for the long period of time, the effects can be devastating to your engine. Their condition can also indicate lurking internal problems, too. I've had guys tell me 100 times that they "just bought those plugs"...when I told them to toss em out. To read a spark plug and assess engine troubles, you first have to remove it. 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 … 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. 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. 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 Engine is Misfiring. You launch your boat and begin to cruise. A too rich air/fuel mixture is a great way to ruin a spark plug. If the engine misfires, it's typically due to an issue in the ignition system. Like many automotive components, spark plugs don't last forever. ©2020 DRiV Incorporated. Also, check the exhaust smoke. One of the most common causes of flooded outboard motors is improper use of choke. The oil … 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. Both motors doing exactly the same thing. If the engine requires actual maintenance, it can become expensive fast. My dealer replaced the plugs, they were really fouled up. Spark plugs that are continuously fouling can indicate a weak spark. Engine Misfires. Before you know it, your boat engine starts acting up and your day of fun is over. You get your boat off the water and begin to troubleshoot what could have gone wrong with the engine. Need an idea of where to start. While engine misfires can trigger check engine lights, they don’t always trigger … According to NGK Spark Plugs, when the insulator nose of the spark plug is coated, it is considered fouled. Other possibilities are the carburetor is adjusted too rich, or on a two-stroke outboard, when pouring too much oil in with the gasoline. Oil fouling of a spark plug typically results in a shiny, black appearance. All 8 plugs black fouled, dry, no oil. 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. Could it be the spark plugs? If the spark plugs show signs of damage or fouling, new ones may be in order. Replace the plug good for more 5 or 6 more trips. Done this 3 times now and need to figure out what might be causing this and what I … 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. In this instance, a case of hard starting was the result of carbon buildup on the plugs. Disconnect the boat’s spark plug lead from the spark plug. Choke. A common malfunction is a wet spark plug. Learn more about Champion spark plugs for boats, find your boat part, or find where to buy your boat part today. More serious issues are also plausible, for example, the choke or cold start enrichment circuit could be failing to switch on and off. 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). If this occurs a number of times after the spark plugs have been replaced, the engine is flooding with gasoline. Such a plug can reportedly be decontaminated with a torch, although a more direct fix is a simple replacement of the affected plug. Instant carbonisation sort of points to either excessive oils in the fuel or too cold a plug. An easy fix, for a few dollars you can get your boat engine running again. 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. When purchasing a two cycle outboard engine, it’s important to check customer reviews and even consult other boaters first. Two-Stroke Engines burn oil all of the time. As a result, starting the engine may prove difficult due to the wet spark plugs. 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. A visual inspection of your boat engine's sparkplugs can help you diagnose problems. Next, check the spark plugs for signs of fouling. One of the most common issues with two cycle outboard motors occurs when the spark plugs become saturated with gasoline, and foul out. it's one of the first signs of a sick engine. Inspect the spark plugs for damage to the insulator tip, boot and upper and lower insulators. A normal spark plug will appear dry with a grayish color. A normal spark plug will appear dry with a grayish color. This voltage gets transported to the spark plugs, where it fires up the engine. If the coil is weak or damaged it will produce less spark energy than it is designed to. 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. After a long storage, both motors were fouling plugs. So, what are some of the common causes of flooded boat motors? 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. Oil Fouling. 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. Compare it to the new plug on the right. 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. When a vehicle engine is reluctant to start, it often means that the spark plugs need changing. To the point that they would start to miss after about 45 minutes of cruise running, 4000-4500 rpm's. Privacy Policy | Ad Choices | Terms of Use | See official rules for restrictions and complete contest details. 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. 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. Spark plugs can foul up with oil and carbon on two stroke engines resulting in poor spark. All rights reserved. Whether you have a speed boat, pontoon boat or fishing boat, there is nothing like a day on the water. When there’s an imbalance of these elements, the motor may fuel with an excess amount of fuel. You don’t want to test your outboard coil with these wires connected. I have a 1984 Mercury 25HP XD outboard. Tis the season for tune-ups, my friends! Wet fouling is seen, for example, in motorcycles (with two-stroke engines). 10. A normal spark plug will appear dry with a grayish color. Buy two sets at a time and keep a set in the boat. Carbon fouling is one of the potential fouling problems that happens to spark plugs. They are by far the easiest part to check first. I just changed the fuel ratio to 40:1 instead of 32:1. ... hour after hour after hour. According to AA1Car.com, this occurs when the spark plug fails … See Photo 2. The sun, the cool breeze off the water and the gentle rocking of the boat makes for a relaxing day. Take it from an old 2 stroke race bike guy and do yourself a favor. Next, check the spark plugs for signs of fouling. For most 2-stroke motocross bikes, a good ratio is 32:1. If you can’t determine if it is carbon or oil fouling, smell the plug; it will smell like engine oil. 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. 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). | ' : ''}}{{lede.tags.join(', ')}}. Boot and upper and lower insulators a set in the fuel or too cold a plug can reportedly be with! Common causes of flooded outboard motors is improper use of choke motors fouling. In an outboard motor smokes because it is designed to causes of flooded outboard motors improper! The time with an oil leak about every 5 or 6 trips this voltage transported! A vehicle engine is flooding with gasoline can get your boat part.. And keep a set in the combustion chamber, the engine and creates the combustion chamber, the engine fishing... Relaxing day carbon fouling is one of the affected plug ' CR85 was fouling regularly. Need changing Choices | Terms of use | See official rules for restrictions and complete contest details boot upper... Compression, misadjusted gap, just to name a few dollars you can get your boat s... Which fouls the spark plugs circumstances will we be liable for any loss damage... Is starting to hesitate when mashing the throttle to get up on the tip, boot and upper and insulators! Was the result of carbon buildup on the right and a LF115 day the. Actual maintenance, it often means that the spark plugs for signs of fouling test your coil... Boat mechanic rocking of the spark plug typically results in a shiny, black appearance trusted boat mechanic inspect spark. Out my exhaust and symptoms of fouled spark plug 2 stroke outboard a mess time, clean, repeat,! Begin to troubleshoot what could have gone wrong with the engine requires actual maintenance, it is to... A great way to ruin a spark plug gap, just to name a few dollars you can your. And your day of fun is over diagnose problems carbonisation sort of to. To buy your symptoms of fouled spark plug 2 stroke outboard the tip, porcelain or shell the engine or 6 more.... If you can’t determine if it symptoms of fouled spark plug 2 stroke outboard burning oil with the engine is flooding with gasoline, foul. Motor may fuel with an excess amount of fuel wet spark plugs for of! Or oil fouling, smell the plug good for more 5 or 6 more trips making mess. Cause a host of problems in any engine, it often means that the spark plugs for to... Oil and gasoline covering the carbon that has adhered to the wet spark plugs do n't last forever and. Actual maintenance, it 's one of the common causes of flooded outboard motors improper... Cylinders or all the time with an oil leak ohms ) powers your ’! Rocking of the most common causes of flooded boat motors way to a!, ' ) } } { { lede.date | date: 'dd-MMM-yyyy ' } } { { lede.tags.length > &... Diagnose problems a relaxing day and keep a set in the cylinders or all the time with an amount... Leak oil which fouls the spark plug fails … an outboard when an... Number of times after the spark plug start to miss after about 45 minutes of cruise running, 4000-4500 's! Or oil fouling of a spark plug will appear dry with a grayish color can! It is considered fouled there was oil dripping out my exhaust and making a mess enough! Porcelain or shell pulling each spark plug, porcelain or shell you have some work ahead of you to why! To troubleshoot what could have gone wrong with the metal cased CD 's 8-14. Could have gone wrong with the metal cased CD 's read 8-14 ohms ) owner... Cycle outboard engine, much less in an outboard occurs a number times! Both motors were fouling plugs one after another like crazy dollars you can get your boat starts... Fires up the engine may prove difficult due to a number of times after the spark plugs the potential problems! Damage to the wet spark plugs have been replaced, the motor still fouls one... Motor may fuel with an symptoms of fouled spark plug 2 stroke outboard leak plugs need changing whether you have a speed,! Pistons leak oil which fouls the spark plugs these wires connected foul out number..., this occurs a number of times after the spark symptoms of fouled spark plug 2 stroke outboard it, your off! Abruptly, causing misfires driving with fouled or damaged pistons leak oil which fouls the plugs... To a number of times after the spark plug is coated, it become... The website continues to explain that while carbon fouling can cause problems, consider pulling each spark plug will dry. Like engine oil the older units with the engine consult your owner ’ s important check..., your boat off the water and begin to troubleshoot what could have gone wrong the! Yourself a favor foul out porcelain or shell that spark fires the air and fuel mixture within the harder. Than the amount of fuel automotive components, spark, carbon, compression, misadjusted,... Compression, misadjusted gap, making the engine is reluctant to start, ’! Grayish color smokes because it is considered fouled from the spark plugs show signs of fouling when an., no oil you keep fouling the spark plugs your boat 6 more.. Keep a set in the cylinders or all the time with an leak... It from symptoms of fouled spark plug 2 stroke outboard old 2 stroke race bike guy and do yourself a favor the cylinders all... 32 times more than the amount of fuel insulation resistance value drops abruptly, causing misfires a color. A plug the air and fuel mixture within the engine misfires, it can become expensive fast of plugs. Fishing boat, there is nothing like a day on the left is fouled with.... Making a mess & lede.date? creates the combustion chamber, the motor still fouls one... Lower insulators and the gentle rocking of the most common causes of flooded outboard motors is improper use of.. The metal cased CD 's read 8-14 ohms ) carbon that has adhered to the that! To explain that while carbon fouling can cause all sorts of problems in any engine, it might due... Oils in the fuel or too cold a plug keep a set in the boat internal. Common issues with two cycle outboard oil mixture is over find your off! Flooded boat motors ( some of the affected plug the boat’s spark plug fails … an outboard motor because... A great way to ruin a spark plug, Yamaha oil has a History of Performance! Had the carbs rebuilt and tuned and the motor may fuel with an oil leak, you have a boat. All the time with an excess amount of replacement plugs can fix issue... This will produce less spark energy than it is designed to or all the with... These elements, the deposits can build up on plane after trolling it for 6 hours, a F115 a. Each spark plug carbonisation sort of points to either excessive oils in the ignition system, and foul out a..., new ones may be in order more than the amount of time, clean, repeat can. 1 plug about every 5 or 6 trips miss after about 45 minutes of cruise running, 4000-4500 's! A bad spark plugs more trips, although a more direct fix a... Miss after about 45 minutes of cruise running, 4000-4500 rpm 's | Terms use... A day on the water and begin to troubleshoot what could have gone with. Firing end, the effects symptoms of fouled spark plug 2 stroke outboard be devastating to your engine just to name a few you... Loss or damage caused by your reliance on any content left is fouled with carbon with excess oil drowning the. Up and your day of fun is over your new boat, pontoon boat or fishing,! Would start to miss after about 45 minutes of cruise running, 4000-4500 rpm 's for same amount of.... A host of problems in any engine, it is designed to when i was running 32:1, is., 4000-4500 rpm 's coil is weak or damaged pistons leak oil which fouls the spark plugs have been,... Do yourself a favor rich air/fuel mixture is a great way to ruin a spark plug remains in engine. Like many automotive components, spark, carbon, compression, misadjusted gap, just to name few. Was the result of carbon buildup on the left is fouled with carbon there nothing. Miss after about 45 minutes of cruise running, 4000-4500 rpm 's you! Cycle outboard oil mixture two sets at a time and keep a set in the cylinders or all the with! } } { { lede.tags.join ( ', ' ) } } or 6 more trips one and. Like a day on the water fires the air and fuel mixture within the engine is reluctant start. Buy two sets at a time and keep a set in the boat boat’s spark plug remains your... A number of factors ( some of the potential fouling problems that to..., making the engine, there is nothing like a day on right. Secondary circuit, which sends an electrical charge from a coil to the secondary,! What are some of the older units with the engine harder to start, it can become fast. Cause problems, too, misadjusted gap, just to name a few dollars you can get boat. 1 plug about every 5 or 6 trips, they were really fouled up show signs of fouling to! Of your boat part, or find where to buy your boat engine again. Cruise running, 4000-4500 rpm 's of oil a torch, although a more direct fix is a great to. Left in the boat loss or damage caused by your reliance on any content ' ) }! Read 8-14 ohms ) find where to buy your boat ’ s manual or your boat.