Ignition points gap too small. I set the hold down screw for the points with a little drag, and adjusted the points according to the dwell meter, while turning the motor with the starter. Even some owners of classic cars find it more practical to replace the points with an aftermarket electronic system. Maintaining the correct spark plug gap is crucial for combustion efficiency, power output, fuel economy, and emissions reduction. 015 they are napa. 020 thou. The issue can be fixed by adjusting the gap through a process that is not too difficult but requires a few specialized tools. Since 1982, Briggs & Stratton engines have used a solid-state ignition. Edit Oct 1, 2004 · When my small block ford had points, I used to remove the distributor cap and adjust the point gap with a dwell meter. The spark plug gap refers to the distance between the center electrode and the ground electrode of a spark plug. This wide gap situation causes excessive arcing at the points and, because of this, your points will prematurely burn and pit. This gap is critical because it dictates the voltage needed to jump across the gap and create the spark that ignites the fuel. Without sufficient electrical charge or if carbon buildup blocks sparks from traveling across the gap, it can make starting your engine a challenge. In this video, I'm showing you how to properly set your ignition points using a feeler gauge. 026" (give or take) and use ignition systems that use 50,000 - 80,000 volts, but more importantly, up to 40 Amps! What is the best spark plug gap? Many think the larger the gap, the better. If the small point-gap was the result of rubbing block wear a check of your timing would have shown it to be retarded by several The points gap will decrease as the rubbing block on the points wears (the rubbing block is a small piece that gets greased with cam lube or points lube as shown above). Performance Implications The choice between a small or big spark plug gap can have profound implications for engine performance: Fuel Efficiency: A properly set spark plug gap can enhance fuel efficiency by ensuring complete combustion. After you are satisfied, set the ignition timing. Discover its importance, ideal gap sizes for ignition, and ways to adjust it. With current engine technology, universally incorporating solid state ignitions and computerised fuel injection, the gaps used are much larger than in the era of carburetors and breaker point distributors, to the extent that spark plug gauges from that era are much too small for measuring the gaps of current cars. . You can reuse these strips again and again, just keep several I see a lot of discussion on point gaps and timing, so here are my assumptions: Point gap on a magneto must be set so the points open when the magnetic field is strongest, so it is critical. DIY Tip: An incorrect plug gap can contribute to a high rate of misfires, so it’s important for you to know the right gap for your engine. The ignition coil gap is the small space between the center electrode of the coil and the ground electrode. Adjusting the points gap by moving the fixed half of the contact breaker points will cause the points to open when the fibre heel is higher or lower on the rising edge of the cam - closing the gap retards the timing, opening the gap advances it. This transfer is uneven, and in effect closes the point gap. ) Has anyone had different results with different spark plug gaps for either points or electronic ignition systems? Or is there no difference? Thanks! Brian Setting the point gap and ignition timing Perform the following whenever the breaker points assembly is replaced or where a timing problem is suspected. Symptoms of a spark plug gap that is too small include lack of ignition power, misfires, poor gas mileage, and spark plug fouling. using the timing tool to set the opening to occur at the right time Failure to lubricate this critical wear point usually results in the points gap closing up as you run the engine. A problem with the gap size on your spark plugs may cause an ignition misfire or harsh engine operation. A spark plug gap that’s too small may seem trivial. Setting the right spark plug gap ensures efficient ignition and optimal fuel burning for improved mileage. The rule of thumb for the spark plug gap on older engines is coil ignition 0. The majority of classic 2-strokes have ignition systems that fall into one of two types: contact points inside a flywheel magneto (Villiers and early Japanese engines) and external contact points mounted on an adjustable plate with an internal flywheel. A gap that is too wide may lead to incomplete combustion, resulting in wasted fuel and increased emissions. Adjust the point gap setting to specifications using a feeler gauge. What is the spark plug gap on a 57 Chevy? 035" is the spark plug gap and not the distributor point gap. Even if there are multiple coils, each with one set of points, then it is still single point. Jun 14, 2025 · Why is It Important to Set Points Gap Correctly? Setting the points gap correctly ensures that the ignition system provides enough current to create a spark at the right time. Adjusting point gap in a Ford distributor Air gap is a fairly critical adjustment in small engine magneto ignition systems. Well, the title says it all: What would be the symptoms of an engine running with spark plugs with the wrong gap? Can we feel it when driving? Thanks! When you have two sets of points on one coil it is called a dual point system. Too-small spark plug gaps may cause… This is the easiest way to set the air gap on an ignition coil and get it perfect every time. Setting the ignition contact point gap may eventually become a lost art, since the points are replaced in modern cars by electronic ignition. However, if the gap is too large, and the ignition system can’t provide the voltage needed to spark across the gap, or turbulence in the combustion chamber blows out the spark, misfires will occur. Yet, it can cause significant engine problems. On the other hand, if the gap is too small, there will be excessive current flow Jun 6, 2016 · Too wide a point gap decreases the dwell angle. The common misconception most newcomers have concerning point ignition systems is that they are difficult to service and tune. Problem Areas: Each time the points open, a very small amount of metal is transferred from one side of the points to the other. The spark plug gap, though small, significantly impacts engine performance by influencing ignition efficiency. What Happens If The Spark Plug Gap Is Too Small A small spark plug gap leads to weak sparks. Watch to find out what these numbers me If the gap between spark plugs and cylinders is too small, not enough voltage will be generated to create a strong enough spark for a successful ignition. Anyway, I bought 16 of them and intend on putting them in both the '70 1100 D truck with it's original points ignition AND my '79 Scout with Pertronix and a flamethrower coil. Point gap on a distributor based system is the best of both worlds for being able to open/close On a four-cylinder engine operating at 3,500 RPM, the points open and close 7,000 times per minute. Adjust the point gap to properly set the dwell before it does. 014" and 0. The net effect is to reduce your spark voltage and duration. We also used a new Innova Profession 2n 6 volt cant get the points opened to . If the points are set too close, the dwell is increased but the points may bounce at higher speed and the idle becomes rough and starting is made harder. Badly retarded timing causes overheating, back firing, poor performance and poor fuel consumption. At anything above an idle this results in very doggy performance. My friend's 1973 Corvette was running horribly due to worn-out points so we replaced them and adjusted the initial points gap. When the gap gets too small, the engine stops - wherever you are and no matter the time. Why does a point gap affect ignition timing? The reason for this is that the points gap directly affects the ignition timing, which is one reason why electronic ignition modules make good sense as the relationship between electronic ignition and ignition timing remains constant, whereas with points gaps it changes with time and wear. The wider the point opening, the smaller the dwell and the smaller the gap, the larger the dwell. proper way to set point gap [Options] [Printer Friendly] [Posting Help] [Return to Forum] [Log in to Reply] Hop to: The points gap is designed to give the correct dwell ange, but with age, cam wear etc this becomes less accurate. It also slightly retards the timing. How to set / adjust the armature air gap on small engines such as lawnmowers. Conversely, if the gap is too large, you may experience a weak spark because it reduces the coil's charging time. (345's both. This gap allows the spark to jump across when high voltage is applied, creating the ignition spark. If the points gap is too small, the heel of the points will meet the cam lobe sooner, advancing the ignition slightly. My recommendation is: Old points style ignition or and 60's early 70's style coils limit your gap to . But it won't start now, it started OK before dismantling. 02" 2. Ideally, check and set the gap, between every major service, and replace the contact breaker after 6,000 miles or 10,000 km, or twice a year. In short, adjusting the size of the points gap alters the internal timing of the magneto. It would appear that there are 2 methods: 1. I've got a B & S 10A902-2072 lawn mower, recently pulled the magneto off yes, I know, not a good idea - I didn't think the gap would be too crucial. Here's how to do it. setting the gap at maximum opening to 0. What are the symptoms of improper point gap? What about plug gap? Add in the indifferent, low-energy spark and incorrect ignition timing caused by worn-out points, and you've got an engine that won't fire--oh, and wet spark plugs too. If the gap is too wide, the ignition system components are required to work harder to jump across the extended gap. In short, either too wide or narrow a point gap will cause a misfire under load. Well, if I'm reading you right you're running points ignition, but the plug gap is set for HEI? There is a difference in plug gaps between conventional (traditional) points ignition and HEI. On the other hand, if the gap is too large, the spark will be too strong and can cause damage to the engine. That’s why it’s important to set the correct gap for your vehicle. This guide provides essential steps and tips for setting points gap accurately, ensuring optimal engine performance and reliability. 021". This can result in engine misfires and reduced performance. The procedure, in a nutshell, is you set point gaps between 0. 16". The smaller the air gap, the better will be the magnetic coupling effect between the flywheel's permanent magnets, and the coil armature's poles. Then you set the timing to the first timing mark. Oct 15, 2011 · Also, having too small of a point gap increases point "dwell" and can cause the points and coils to overheat. Fuel economy may suffer, and acceleration can be sluggish, causing frustration during drives. 018 - 0. Jan 4, 2026 · A gap that is too small increases the dwell, which can cause the coil to overheat and reduce high-RPM performance due to insufficient time for the points to fully open. Points are the simplest ignition system since the points are both the sensor and actuator. Understanding the consequences of having a spark plug gap that is too small is crucial for car owners and enthusiasts alike. Why it's important to set your ignition points gap and dwell before you play with your timing. This does not give the coil sufficient time to charge, resulting in a weak spark. Measuring dwell angle takes away any effects of worn or pitted points, slight play in the distributor etc. Just an FYI; most very high powered blown gas, blown alcohol, and even blown fuelers run gaps as small as . Rotate the crankshaft so that the cam that operates the points is at the highest location and the points are wide open. 025 thou and magneto ignition 0. Anyone know what the gap from the magneto armature to the rotor should be on these Further adjustments can then be made by adjusting the position of the plate upon which the points assembly is mounted. The contact-breaker setting is often neglected, but it is vital to good running. Murphy's law usually dictates that this will occur at your farthest point from tools or assistance. Spark plugs can misfire or produce a spark that doesn’t connect with the electrode, the ignition coil can overheat as it requires higher voltage to generate the spark, and control module failures can result for the same reason. I'm setting up the ignition on my 1968 6hp Johnson Seahorse and just wondered how critical it is to get the points gap exactly right. Point Settings Explained If the gap is too small the coil's magnetic field will not be fully collapsed before it begins to re-charge. However, if the gap is too large, and the ignition system can't provide the voltage needed to spark across the gap, or turbulence in the combustion chamber blows out the spark, misfires will occur. My tractor misses at WOT not too noticable if it is sitting but if in road gear going up uncline it is noticeable. Three: my point gap is probably too small, which is why, according to the Sears timing light I've just discovered in the garage, my timing is way, way too late. This video covers basic adjustments for most automotive ignition systems, specifically, the ignition points' dwell angle. If the point gap is set too wide, they open gradually and the dwell angle - the time they remain closed - is small. A gap that is too wide will make it difficult for the spark to jump, resulting in a weak spark or no spark at all. Whatever the gap was when the engine ran it's best overall, is where you should gap your plugs at. Because dealing with points can be a pain, many folks who road-trip their vintage cars replace the points and condenser with a small electronic triggering module. What is the best spark plug gap for fuel economy? Briggs & Stratton is a manufacturer of small engines used in lawn and garden equipment such as lawn mowers, rototillers, snow blowers and more. 035 as these style ignition systems only put out about 30k volts and the spark will have a hard time jumping the gap between electrode and ground strap at any gap wider than that. A large spark plug gap setting requires a higher voltage to jump the distance between the electrodes. 016" to . The spark plug gap is the tiny space where the ignition spark is created. In this lesson Mark Simpson explains how points work and are installed, and shows how to properly set the point gap and the dwell. The distributor point gap for the 1957 six-cylinder engines is . Here's the reality of how sim If the gap is too small, the spark may not occur due to insufficient separation to disconnect power to the coil. But setting the gap is only a p If the distributor is fitted with points rather than an electronic ignition trigger, it’s important to check the points gap before you start because if it’s incorrect, that will also affect the timing. How to Set Ignition Timing Setting 2-stroke ignition timing is fairly simple. If there is only one set of points per coil then it is a single point system. Too wide of a point gap can lead to a weak spark. Conversely, a gap that is too wide decreases the dwell, resulting in a weak spark because the coil does not have enough time to fully saturate with current. If the points gap is too large, there will be sufficient current flow and strong sparks, resulting in misfiring or engine stalling. What happens if the ignition coil gap is too narrow? A too- narrow ignition coil gap can prevent the spark from jumping, leading to misfires and poor engine performance. On the other hand, too much gap can lead to misfires, reduced engine performance, and potential damage to the ignition system. I recommend setting your point gap with a feeler gauge and fine tuning with a dwell meter. It's quick, simple, and very important for maintaining your ignition system! Explaining the mechanics general rule of thumb 10-20-30 for the coil to flywheel, ignition point and spark plug gaps. A gap that is too narrow may not provide enough spark to properly ignite the fuel-air mixture, while a gap that is too wide can cause a weak spark or a high voltage requirement, potentially leading to ignition failure. The ideal spark plug gap is specified by the engine manufacturer and varies depending on the engine type and design. In depth video on points and condenser and complete ignition system tune up, on older engines that use points and condenser, before the newer magnetron electronic ignition came out. How to set the coil and magneto air gap on Briggs and Stratton engine. ovdw7s, rtb8, ikevx, hmfqhz, y8csye, wkmmmk, kef3, uqgnl, ugxz, nzhny,