2 Stroke Engine Backfires But Wont Start

Year, Make, Model. Forum Main Tech Help/Race Shop 08 KX250F - low compression, won't start. I have checked the compression, to verify the valves are ok. when i pull the start nothing happens, not even the. The rapid burn that occurs while the exhaust valve is open causes a backfire. I hope that is all it takes. The mower started after that and ran fine while I cut the grass. However, if by opening the throttle it will start in a turn or two, the orifice is satisfactory. Re: wont start just backfires. 4: Backfires in Exhaust Note: It is normal for many high performance exhaust systems to moderately backfire or pop when the throttle is closed from mid-to-high rpm. I've seen similar on car engines when the head gasket has gone between two cylinders The effect on a 2 stroke would be to get it to "pop" back through the inlet manifold and exhaust. Is a back fire caused by to lean high needle mixture. I'd say two things might have happened: Your float is a little sticky, your float needle and seat could be a little gummy or old and not seal well. but it would be at the top of the exhaust stroke. 4-STROKE STARTING TIPS: With the four-stroke revolution bumping the rev limiter, more and more two-stroke fiends are entering the world of cams and valves and pumper carbs. I have plenty of gas going to the carb and the solenoid on the bottom is working fine. Note: Backfire and afterfire through the carburetor will not harm the engine at all! Find out the most common causes and possible fixes for engine backfire and afterfire. First, and most logically, pop off the gas. Cylinder compression ratio in two stroke engines I wrote this post a few weeks back, but its currently about 2 pages and only halfway done. Your lawn mower blade is dull. Why Won't My Engine Start ? You just finished building an engine or are reviving one that has sat for a while and now it simply will not start. Carefully pull apart the carburetor, wash all parts, fuel tank, line and air box also, with a good degreaser. 01-27-2004, 05:01 PM. 5 won't start, cranks hard, and backfires. My Engine Turns Over OK But It Won't Start If your engine won't crank or turn over, go HERE. its not working. Check for fuel restriction. I have an 01 Scrambler 500 4x4. 96 Chevy S10 Blazer with 4. Then wouldnt start no matter what I did. Engine backfires can be produced by a vacuum leak, bad timing, problems in the ignition system, a faulty sensor, an exhaust leak, or some other system fault. You may have put the base gasket on wrong or it is the wrong one for this carb & engine combination. Engine Cranks But Will Not Start (No Smoke From Exhaust) 13 Things About the 7. If you know how to start a 2 stroke properly then you will not need anything more than the choke. There should be a better oil level indicator. Rotax-Owner. However, you'd almost need to use a good caliper to measure the wear out. 1) Patience and 2) penetrating oil. If it won't fire on the compression stroke, it will fire at the end of the exhaust stroke and ignite the intake charge on valve overlap. it wont start it turns over but does not start. #2 Excessive under hood temperature: Ensure fuel line is not located too close to heat sources such as the exhaust or block, causing expanding fuel to be forced past the needle and seat. 1) Never use the off-the. engine still turns over, but is not even trying to start. This will help locate the system that is having a problem and needs repair. If you’ve ruled out electrical, spark/ignition and fuel problems, but the engine still won’t start, it may have an internal problem, such as low compression. A thick coating of soot will form inside the exhaust pipes, which must be thoroughly cleaned, and the same attention should be paid to the expansion chamber. Sprint Bread 50 GY6 here. This is an old OS FS-120 Serpass I have had for about three years and tonight was the first time I ran the motor. It's still a 28 oz balancer ! The engine has been apart before from the signs of different gaskets that are not stock and signs of silicon being used. There might be a pending code. On a two-stroke engine low compression means the rings are not sealing right. Things were looking up: I replaced the spark plug, cleaned out the exhaust, adjusted the idle / fuel screws, and even replaced the brakes (I can stop now!). It started when I turned the lights on it would kill the battery, so I disconnected the light switch and charged the battery but it still won't turn over. 2006 Mustang Cranks but won't. So the engine both cranks and gets spark but just wont start. Next, you should check the fuses on your car. wont start got my motor in an it ran for 10 seconds. 0L MPI 350 MAG MPI MX 6. Had a PE 250 which sheared the woodruff key on a number of occasions. i can only get the bike to backfire through the exaust hard enough to blow the exaust outa the spark rester. In other words it needs "enriching". So I'm back home from uni for afew days during summer. You may have put the base gasket on wrong or it is the wrong one for this carb & engine combination. Sprint Bread 50 GY6 here. MerCruiser Engine Wont Start - Troubleshooting Manual MerCruiser troubleshooting can determine faults and help correct mechanical or electrical system problems. STIHL MM55 WONT START WONT STAY RUNNING - A few years back my trusty old MANTIS TILLER died after many years of faithful service. In such a scenario, the engine is prone to stalling as you drive. Got a 21 hp Briggs on a craftmans riding mower and it was giving a neighbor of mine a lot of trouble and he wanted me to look at it. I was told the battery is probably on its last legs and it hasn't been ridden for days and before that probably not regularly for ages. But it still pops, even when I speed up the notor. If it is cranking too slow the engine will not start. He never does anything except change the oil and lube the auger shaft -- that's it. We have checked the following: coil - replaced fuses - good control module (ecm) - replaced plug wires - replaced. well i took apart the mini moto and left the engine for a while. The sizing of the orifice to the engine can be checked for accuracy by energizing the SV valve separate from the starting circuit. Why? 84 Answers. I have an OEM fuel filter and will try to replace that and add some fresh gas. In other words it needs "enriching". 2 stroke 250 backfire and kick start kicking back problem found No Start Troubleshooting A 2 Stroke Engine 12 Reasons a 2 Stroke Cycle Engine Loses Power/Won't Start/Cuts Out/Bog Down. If no warning lights are on continue down this guide. I drained the gas tank, and put 2 or 3 gallons of fresh fuel. It will start okay when primed for about 5 secs and then dies irrespective of what you do with the choke or throttle. This yard blower delivers 510 CFM and 215 MPH blowing performance for a powerful impact. wont pick up or nuthin Thats the same thing my friends did we couldnt get it started just a backfire here and there. Check for fuel restriction. when i pull the start nothing happens, not even the. If you're in this situation, there is hope Here's some things to check. In a 2-stroke engine, it takes one full revolution (2 stages) to complete 1 power stroke. STIHL MM55 WONT START WONT STAY RUNNING. #2 Excessive under hood temperature: Ensure fuel line is not located too close to heat sources such as the exhaust or block, causing expanding fuel to be forced past the needle and seat. Bigger carburetors, higher compression ratios, altered port timings and expansion. I have plenty of gas going to the carb and the solenoid on the bottom is working fine. Checked spark. I cleaned the carb and set the timing. A download outboard repair manual is a book of instructions for learning how to maintain, service, troubleshoot, and overhaul the engine to factory specifications, including procedures for engine won't start. The engine turns but it won't start working. Fortunately, due its spacious engine compartment, the troubleshooting steps for a nonstarting jeep are easy to perform. Sometimes, locating the source won't take you much time, other times it can prove difficult. Check for fuel restriction. Learn how to diagnose and solve an engine backfiring problem… in case it is a problem. My dad has a little bike 2 stroke engine that won't start, so he has given me the job of attempting to get the little thing to start. I fixed the wires and the electrics are now good. Let's dig in to see what to do when a mower won't start. How to Diagnose Two Cycle/Two Stroke Engines September 2, 2011 This article outlines the appropriate steps needed to accurately diagnose your two-cycle lawn equipment engines, walking you through fuel system, ignition system and compression system diagnoses. They have a single cylinder and run on a mix of gasoline and oil. A back-fire or backfire is combustion or an explosion produced by a running internal combustion engine that occurs in the air intake system rather than inside the combustion chamber. If you know how to start a 2 stroke properly then you will not need anything more than the choke. won't start. My choke wont stay up after. In almost all cases, whether it is a 2 cycle or 4 cycle engine, golf cart backfiring is caused by the accelerator cable being out of adjustment at the throttle plate of the carburetor. Additionally, sparks need to happen at the right time and. Year, Make, Model. Unlike other diesel engines the Powerstroke has two oil pumps. Top 25 Reasons Your Boat's Engine Wont Start Even the mood created by this idyllic scene can be ruined by a hard to start marine engine. String Trimmer Won't Work: 2-Stroke Engine and can be spitting or backfiring through the carburetor or exhaust. I was told the battery is probably on its last legs and it hasn't been ridden for days and before that probably not regularly for ages. Posted on July 31, 2014 by Rosy Maria Most of the Tecumseh engines that are used as small vehicles such as lawn mowers, snow blowers, carburetors, generators, etc. Rules, New Member Introductions, and Forum Information. You will. It was frustating. Bigger carburetors, higher compression ratios, altered port timings and expansion. An engine backfire is an explosion produced by an internal combustion engine. its not working. a backfire is normally caused by an exhaust or intake valve that fails to open, or ignition timing that is way off causing the spark plug to fire at the wrong time when the valves are in the wrong position. i got home and took the heads off and water was everywhere. Briggs & Stratton 14. When someone posts 3 or more highly improbable, if not, impossible things, I throw a flag. I Can turn over the car just fine. How Can You Tell When Your ATV Backfires? Diagnosing a backfire is pretty darn simple. This is a discussion on WD-40 as starting fluid for 2 cycle engines. one ought t. So, your outboard won't start. So ive been battling with this bike now and still nothing. The engine turns but it won't start working. A thick coating of soot will form inside the exhaust pipes, which must be thoroughly cleaned, and the same attention should be paid to the expansion chamber. Turns over but won't start. Repeat for ALL cylinders. I need some help on my 2-Stroke, Polaris 250. When that was done, I syphoned all the old fuel out, and replaced it with fresh 91. What he needs is an understanding of what air leaks are and how to check for them. My focus is on the unique features found in boats that are the common sources of a "no-start. #1 is on the passengers side closest to the back firewall. Greeting esteemed mower owners, I have a 15 year old Craftsman tractor with a 17HP OHV Briggs and Stratton engine that won't start but occasionlly backfires. Adjust choke if necessary. Starting an old carbureted two stroke when cold I have a 1991 90 HP 2 stroke Yamaha. Thus, use of a very volatile agent like starting fluid can easily promote backfires through the carburetor and intake fuel path of small 2 strokes, especially in summer time ambient temperatures. Real backfiring means the engine is not properly timed and the fuel/air mix is getting a spark and ignition at the wrong time (when the intake valve is open). It chucked a MAS 16x8 prop about 15 yard. The biggest dilemma these converts will face will be lighting the fire within the beast. I'm an auto-mechanic by trade, and I've had 2 stroke bikes and jetski's throughout my younger years. If you didn't find what you were looking for here, feel free to check out our archives of old scooter running/stopping questions. But i still have one problem… It is still hard to start the engine especially in the morning, and sometimes even if the engine is still warm I need to rev a little bit to make it start. They have a single cylinder and run on a mix of gasoline and oil. Com General Discussion > Motorcycle Mods and Maintenance: Help 2 Stroke sparks, doesn't run but backfires? So start goofing around. Clean air filter: Remove line at carb. More than likely your engine is "popping" not really backfiring. air, float seems to be working fine. When its on for about 30sec,readjust the idle. There are no signs that the engine wants to fire up, it just continues to crank. Carefully pull apart the carburetor, wash all parts, fuel tank, line and air box also, with a good degreaser. Re: 1977 35HP johnson backfire's then wont start After a few pulls try pulling the spark plugs and see if they are soaked with fuel, if they are then the carb is flooding the engine, the float could be stuck down and the needle is just letting the fuel flow out freely. It worked fine up until two weeks ago. 11-27-10 10:37 AM - Post# 2010083 In response to someotherguy People often come here looking for help because their truck won't start. Discussion in '2 Stroke Bicycle Engines & Kits Problem--won't start. On a Chevy engine you might have to move the oil pump slot/rod with a long flat-head screwdriver and do your best to put the rotor around the #1 position. As its a been 20 years since i last messed with a 2 stroke. Average repair cost is $380 at 93,950 miles. The most common problem with both two- and four-stroke engines begin with the fuel system. If the snow blower won’t start up, wait an hour or two to allow the fuel stabilizer more time to dissolve residue, and then try again. Had spark at the tip of plug. Won't start when hot: If the engine spins too easily check for valves that are sticking open. When the engine is warm it doesn't need enriching and if you use the choke you'll "flood" the carburetor with fuel (make it too rich) and the engine won't start for a few minutes until the excess fuel evaporates. One factor you probably did not consider as to why your chainsaw won't start is a result of having bad fuel in the tank. How to Fix a Lawn Mower That Won't Start. It ended up being that the ring on one side of the piston was messed up and the compression dropped to about 20psi. It does feel hot on my leg when wearing shorts while riding but the high temp light never comes on. I have verified fuel to the engine, and tested the coils for spark. Now last week I came home determined to get the bike running because the weather is getting really nice. Instruction labels for operation and storage well marked. It backfires but will not start. I was told the battery is probably on its last legs and it hasn't been ridden for days and before that probably not regularly for ages. 2 cycle engine has spark and new carb won't start [closed] most small 2-stroke motors have a reed. But if I go sailing, it wont start for many pulls when I want to get back to the dock. The one barrel carb on the 6 cylinder engine on my Edsel keeps backfiring unless I pull out the manual choke a little. Problems started with p0011 and p0014. Whether the bike is a two- or four-stroke, it's almost always easiest to check the fuel supply first. 1) Never use the off-the. I thought maybe the flywheel key had been sheared but it appears OK. Misfire, Backfiring 4 Answers. If your engine won't crank at all, or cranks very slow, or the security light stays on, check the first part Why a car won't start troubleshooting tips. Basically, without a spark your car won’t start. Usually a storage related engine seizure for a two stroke outboard meant the end at worst and poor reliability and big repair bill at best. I turn the car to the on position and I hear a "humm" in the tank of the fuel pump kicking in. Two stroke engine wont start? hi, i have a small two stroke engine from a mini moto. within the Broken Arrow forums, part of the Gun Forum category; Little trick an old woodcutter taught me. I pulled the shroud and pull start off and am using a drill to crank the engine as pull start was killing my arm. My Nissan 5hp 2-stroke starts on the first or second pull after sitting on the dock for a week. My engine is the 5. Backfire i have a 1989 yz 250 that wont start but has fuel compression and spark. wont start got my motor in an it ran for 10 seconds. The motor is backfiring out of the carb and exhaust is spitting flame the carb is spitting gas out of it, and I'm at a complete loss please help as this is my only transportation to and from work!. I turn the car to the on position and I hear a "humm" in the tank of the fuel pump kicking in. As gas runs into the cylinder, the coil sends up a spark to ignite the gas. Afterfire occurs after the engine has been shut off. my two stroke strimmer will not start? I have a two stroke Victa strimmer that was running , albeit quite poorly, but cut out and will not start now. Then consider registering so that you may make posts, and view the additional content available. Some can be a little stubborn but for the most part any engine not past its prime can be hand-started in a couple flips. If still you have a no start engine condition then probably it's best to consult with a qualified engine mechanic as somewhere in the trouble shooting process something has been over looked. Coil is dirty but should be working. Maybe it's a old machine your trying to bring back to life, or a dependable engine that never lets you down. Opti-2 and Tanaka Perfect Mix are two examples of these oils. Backfire and won?t start. This will help locate the system that is having a problem and needs repair. com FREE DELIVERY possible on eligible purchases. For about a month before it stopped working, the engine would NOT idle. The first step in a 7. expansion of metal parts where bolts/screws aren't tight enough, breakdown of the condenser for the ignition points (if equipped), or a possibility of a crack somewhere. i hadnt started it for about 6 months until today when i tried to. Engine Will Rotate But Not Will Not Start (Fire). We have a 8hp 2/s outboard that runs perfectly, ideling, forward and reverse gears. You might get it started, but more than likely you will have to break down the carb and thoroughly clean out all the nooks and crannies. This INSTANT DOWNLOAD 4 horsepower Mercury, Mariner, Yamaha, Suzuki, Johnson and Evinrude outboard engine repair manual was designed for do-it-yourself mechanics and factory trained technicians. First off, if you've been riding and your bike won't start after a stall or hitting the dirt then read What is a Hot Start. Don't hold the choke on for 15 seconds then release it, that will almost certainly flood the motor. Additionally, sparks need to happen at the right time and. Start each needle at 1 1/2 turns out and work from there. Adjust choke if necessary. gx390 backfires, wont start On a four stroke engine, (intake, compression, power, exhaust), the engine makes two complete revolutions to accomplish this cycle. How to Diagnose Two Cycle/Two Stroke Engines September 2, 2011 This article outlines the appropriate steps needed to accurately diagnose your two-cycle lawn equipment engines, walking you through fuel system, ignition system and compression system diagnoses. The engine needs choked only when cold to add more fuel to the mix. It will start okay when primed for about 5 secs and then dies irrespective of what you do with the choke or throttle. That you've flooded the engine by trying to start it, or that the lower end is loaded up (because you left the gas petcock on). Any dirt bike, whether it be a 2 stroke or 4 stroke, MUST have these 4 prerequisites to start and run:. any suggestions would be much appreciated thanks. It's still a 28 oz balancer ! The engine has been apart before from the signs of different gaskets that are not stock and signs of silicon being used. It ended up being that the ring on one side of the piston was messed up and the compression dropped to about 20psi. Whether the bike is a two- or four-stroke, it's almost always easiest to check the fuel supply first. Starts easy. Make sure the needle and seat are both clean before installing the needle, BUT be CAREFUL not to damage either by cleaning with metal (wire). I have a 2000 silverado z71, with 288K, recently replaced fuel pump and filter about 3 weeks ago, was running great, until last week when it started to hesitate bad and back fire under acceleration, it ran good in idle and underload until is warmed up then when you tried to accelerate it would bog down bad and start popping like tiny backfires and the more gas you give it the engine falls flat. Usually a storage related engine seizure for a two stroke outboard meant the end at worst and poor reliability and big repair bill at best. I have a four year-old Simp Pro with B&S OHV. I pulled the shroud and pull start off and am using a drill to crank the engine as pull start was killing my arm. the rotor should point at #1 plug wire. Gas shut off and tank valve work well. Lower vibration. If no warning lights are on continue down this guide. When turning it over to try and start it now all I get is a backfire/afterfire through the exhaust. Just a thought. since then i have replaced the head gaskets. I have inherited a Craftsman Lawn tractor and am trying to get it going. By John Tiger Photos By Mark Corke. It is very possible that your ignition module is bad. My engine is the 5. Step-by-step troubleshooting will help you pinpoint problems. You will. You would want to check fuses for systems such as: Starter Circuit, Ignition, EIS, Fuel Pump. Then consider registering so that you may make posts, and view the additional content available. I went to cut the grass again last night and the mower won't start, it will backfire after every 2-3 pulls. 16 to 1 ratio with a brand new engine and 25 to 1 with a used engine. If you are having trouble starting your nitro rc car engine it can be very frustrating! There are many different reasons why a nitro engine might fail to start. Why is the engine bogging under acceleration? I recently managed to get the moped running properly, albeit for only a short time. Your lawn mower blade is dull. com FREE DELIVERY possible on eligible purchases. Two stroke engine wont start? hi, i have a small two stroke engine from a mini moto. I started it and it died about a block down the road. It shut off in the middle of cutting and that was that. Instruction labels for operation and storage well marked. While it's not dangerous, it can be a symptom of other problems, and should be addressed. It's still so strange to me that even with a spark, a combustant(gas/ether) and air the engine won't start, not even with the ether sprayed into the spark plug hole and carb inlet. The first step in a 7. The backpressure can cause backfiring and rough running and in some cases will prevent the engine from starting at all. There are many things that can cause a riding mower to refuse to fire up. Then when I tried to start it,it backfired through the intake. The engine backfire through the exhaust ONLY and not all the time either ! Backfire through the driver side on the number 5-6-7-8 cylinders. Re: 1981 Johnson 15hp won't start, only backfires I reversed the plug wires to the coils and it fired right up and purred like a cat, don't know why I didn't try that before, I guess I just didn't think any one would have monkied with the wires, the wires looked like they hadn't been moved since it was new. Replaced the coil and carburator. 3 Power Stroke Engine You May Not Have Known; 2 Common Reasons Diesel Fuel. This problem has a relatively simple cure. My motor would take 3-6 pulls to start until I found a little corrosion on the fly wheel/ magneto. 2011 malibu lt 2. its not working. I cleaned the air filter and plug. Backfire in engines is caused by simple chemical malfunctions that can be easily rectified. Is it possible that the fact that it rained is a coincidence? Could the fuel just be old? If you leave a two-stroke engine sitting too long with mixed fuel/oil in the tank, the mix will lose some of its lubricating properties---sometimes enough that when you try to start the engine it'll run for a moment, then overheat from lack of lubrication and stop. wont start got my motor in an it ran for 10 seconds. String Trimmer Won't Work: 2-Stroke Engine and can be spitting or backfiring through the carburetor or exhaust. I fixed the wires and the electrics are now good. If fuel and electrical is all good/correct it is often the case in these symptoms that motor cycle spark plugs that although looking good and firing outside of the engine are breaking down and will not fire under compression pressures on a power stroke but will fire unburned fuel on the. ) A number of issues cause an engine to seize and most require an adept mechanic to diagnose and remedy. yep a 2 stroke can't backfire because there are no valves. Why should an engine that has everything right still refuse to start. Re: 2 cycle ezgo won't start, maybe engine problem? Rumor has it that the cylinders wear out of round - there has been guys who hone the cylinder and get a new piston and rings, and have made out OK. Stalling And Backfiring. Once the engine is warm enough to take it off choke, drive the vehicle around on flat hard ground. When it first appeared I took it to the local Yamaha dealer who was unable to get the alarm to reappear on the bench, and stated no codes were found, please pay me hundreds of dollars. Thanks for asking your scooter questions about scooter running and stopping issues, and please check back often for new answers and comments. 5hp, Model 28V707, Type 1113-E1, Code 020628ZD in a Murray. All the 4 stroke dirt bikes are equipped with Keihin FCR carburetors, so this post should guide you in the right direction no matter what brand you own. When we would get a phone call at the marina, "My boat won't start" here's what we'd typically say:. I has been serviced each year prior to use. By "reading" the color of the plug you can tell a lot of things about how the engine is running. If fuel and electrical is all good/correct it is often the case in these symptoms that motor cycle spark plugs that although looking good and firing outside of the engine are breaking down and will not fire under compression pressures on a power stroke but will fire unburned fuel on the. It worked fine up until two weeks ago. I think a basic description of timing might help sort out a lot of this. Good afternoon, I have a problem with my Beetle 2004 and hope someone can give me a hand. I cleaned the carb and set the timing. Had a PE 250 which sheared the woodruff key on a number of occasions. It's usually not too hard and your scooter should start ideally on the 1st kick, but 2nd or 3rd kick is OK too. Whether the bike is a two- or four-stroke, it's almost always easiest to check the fuel supply first. Later in the week I cut the grass again without issue. I have a four year-old Simp Pro with B&S OHV. Starting a Model Aircraft Engine. 3 Power Stroke Engine You May Not Have Known; 2 Common Reasons Diesel Fuel. First off, if you've been riding and your bike won't start after a stall or hitting the dirt then read What is a Hot Start. com is a web based support system which provides a common access point for locating key Information - Education - Support for their Rotax Aircraft Engines such as the Rotax 912, Rotax 914, Rotax 912 iS, Rotax 915 iS, Rotax 503 and Rotax 582. Did the same thing again. Although the techniques for kick-starting an old motorcycle are basically the same, every bike is a little different - even the same makes and models can be slightly different. I've had the lawn mower about two or three years now brought new ,eco power Torque I think. Page 2 of 3 - JD 425 sputters, quits, backfires ? - posted in John Deere Tractor Forum: I got a chance to work the tractor this afternoon. I can get it to start but it backfires then shuts off it looks like fuel is getting to it. After starting the engine and ridng for about 2 minutes, the engine stopped. Won't Work - 2-Stroke Engine and Carburetor Troubleshooting" but I'm not. Turn fuel to off position and try starting engine with. E-Storm BT80 - Electric Start This is the all new 80cc electric start 2 stroke kit. Yes, a two-stroke is a little stiff at -34 degrees but they WILL start. Make sure the needle and seat are both clean before installing the needle, BUT be CAREFUL not to damage either by cleaning with metal (wire). With a spring assisted start system and 17 in. INSTANTLY DOWNLOAD a 60 horsepower outboard repair manual straight to your computer in seconds. Once you have the engine information, locate a parts list and exploded diagram by entering the brand and model number into a search engine. Compression. So, we?ve enlisted the top revolutionaries in the sport to teach the masses how they. I'm about out of options, we pulled the engine out and re-tested for air leaks and found none although I checked the backplate screws and got about a 16th of a turn on them. That you've flooded the engine by trying to start it, or that the lower end is loaded up (because you left the gas petcock on). Won't start when hot: If the engine spins too easily check for valves that are sticking open. My focus is on the unique features found in boats that are the common sources of a "no-start. Since day one, it has been nearly impossible to turn off the machine without a backfire. The Dawg Pound. In other words it needs "enriching". According to Briggs & Stratton, a leading manufacturer of lawnmower engines, muffler backfires won't harm your lawnmower, but some backfires originate inside the engine and aren't. I was told the battery is probably on its last legs and it hasn't been ridden for days and before that probably not regularly for ages. Usually there is a nut or bolt on the crank end that can be used to try and turn the engine but the danger of breaking it off means a safer alternative is to use a lever on the ring gear through the starter motor aperture. They are ether based, and you just squirt in in the intake for a second or so, and it'll start first pull. Now last week I came home determined to get the bike running because the weather is getting really nice. You probably have lacquer build up in the jets (ports) of the carb. 2 stroke 250 backfire and kick start kicking back problem found No Start Troubleshooting A 2 Stroke Engine 12 Reasons a 2 Stroke Cycle Engine Loses Power/Won't Start/Cuts Out/Bog Down. Usually a storage related engine seizure for a two stroke outboard meant the end at worst and poor reliability and big repair bill at best. 5 kohler engine.