Small Engine Idles But Dies When Throttle

Start with the control in neutral, no fast idle advance in the throttle, cables connected to the control. It's an introduction to small engines and covers many of the things that apply to 2-stroke engines (which will be covered on this page). Also it needs to relearn the idle position after a battery change. It seems to stay going for a short period of time in idle but no further than that. Along with vernier controls for manual applications. New battery, replaced round fuses with contemporary plug in fuses. the engine wants to tach up right then and there in the current gear the car is traveling in, it may not be possible. Run the engine until the fuel system is dry (Warning! Do not operate the throttle, run the equipment only at idle speed until the engine stops!). General K-series related talk. When a driver releases the accelerator, the engine returns to the idle speed. I took it for a test drive and got around the driveway fine but at the end of my driveway is an uphill. I talked to a small engine guy, he's 90% sure it has to do with the cheap ($10) aftermarket carb I bought. For example, on Tecumseh TVS, LEV, TVM, TVXL and other similar engines, the governor arm rocks in the counter clockwise direction to close the throttle to idle. My bike (04crf250) will idle perfectly,but when i give it gas it seems to be fine for about 2 seconds and then the revs drop way down or the bike shuts off depending on how long/much throttle i give it, and it wont start when the choke is on. putting a tablespoon of gas in the throat of carburetor, engine starts immediately and runs 2-3 seconds until tablespoon of gas is consumed Fuel blockage somewhere???? I am at wits end, I've never had a problem like this in all my years of small engines. Set the float at exactly 9/32". This will allow fast idle on cold start-ups and you won't have to "feather" the throttle for 2-3 minutes till it will idle on it's own. Position the application throttle control to fast then back it off approximately 3/16" (4. Now release the throttle and watch the gauge as the speed drops. How to Adjust the Carburetor on Homelite Chainsaw. Typically speaking, for gasoline engines you'll find that per liter of displacement, the engine will burn around 0. NOTE: these faults represent the combined experience of over 2,300 owners on the Forum and over 400 members of the Mailing List - it is not to suggest that any Scorpio will develop all of these faults, or even any of them. This is caused by vacuum in the intake tract sucking oil down past worn valve guided into the cylinders, and the oil being burned immediately on reapplication of throttle. On a cold winter day (minus 2-3) I need full choke to start, then half for 1-2 miles. Problem is engine starts and idles fine but as soon as you give it gas it dies everytime. If the engine catches or starts for one or two seconds when you spray the fluid, then. The idle jet affects engine operation up to around 2500-3000 RPMs! Almost every dual carb application I have seen with VW engines use a 55-60 idle jet. Opening the throttle screw will allow more metered air past the throttle body when the engine is cold and can solve the cold idle problem, but will also cause your engine to idle high when warm. When pushing the throttle the engine is instantly responsive and runs great. It idling could mean that it's sucking air, and can compensate at idle but not when the throttle is open. No upgrades just bone stock carbs. OK, so I've got my engine idle portion tuned well in my opinion. The engine has been running great, the only problem is that it backfires sometimes when shutting it off. Along with vernier controls for manual applications. For stopping the engine, the black lead wire from the coil should be grounded to the engine body, or the throttle valve should be closed completely. This keeps the engine from doing exactly as you describe. Failure of this device can cause the engine to idle too high or the engine to run lean. Not just any air-to-fuel ratio will work, it must be close to optimal for a snappy and responsive engine. I THINK YOU STILL HAVE A CARBURETOR PROBLEM BUT FIRST REMOVE THE MUFFLER AND LOOK FOR A SCORED CYLINDER OR PISTONIF SCORING SHOWS UP, IT IS UNREPAIRABLE ECONOMICALY. Runs fine when cold. It doesn't take much debris to allow idle but falls on its face when given throttle. The truck starts fine and idles fine but after about thirty seconds starts to puff white smoke. On nitro helis it's common to have to adjust your idle speed slightly, usually to make it easier to start. Depress the trigger and check the acceleration of the engine. With the engine running, loosen the throttle cable clamp screw enough to slide the cable. If you're new to Tech Support Guy, we highly recommend that you visit our Guide for New Members. When an otherwise properly functioning weed eater sputters and stalls, it can be frustrating and add time to your chores. They both start but as soon as they get hot they die. Why is the engine bogging under acceleration? I recently managed to get the moped running properly, albeit for only a short time. How to Determine Why a Car Stalls at Intersections. If your like me you didn't have a dad growing up. At idle, your engine is turning relatively slowly, let’s say 1000 rpms. If I unplug it the car starts right up and idles fine. When your lawn mower or rototiller won't start or stalls while you're using it, the problem is usually fairly easy to solve, requiring maintenance of the spark plugs, air and fuel filters and the carburetor. A bit of rubber melts, comes loose and travels to the carb. I've checked the gas mixture and it's currently at 25:1 I've also had the mixture up to about 30:1 and the problem continued It has good fuel lines with a fuel filter in place I've taken apart the carburetor and cleaned it out with some carb cleaner. function that allows engine to accept light to moderate loads w/o stalling the engine @ idle the governor spring applies no tension, so it does not open the throttle plate if the engine is placed under load can be fixed by adding a governed idle spring. It seems to idle fine but whenever I give it the smallest amount of throttle is dies. If the engine bogs, sucks air (like it. If the engine's RPM's rev up at the last second and then the engine dies than you are running too lean. Engine with fuel injected system has a part called throttle position sensor, the purpose of the device is to measure how far the driver pressed the gas pedal and thus the throttle. Yes, once its running and building pressure it runs great, builds to 120psi quickly then to idle. Intermittent stalling immediately after starting or punching gas There is gas, the starter is fine, the battery is good. One of the easiest ways to check for a base engine Mechanical problem would be to use a handheld Vacuum gauge. Could this be a sensor of some sort going out? I do not get a check engine light either. If the car idles rough or cuts off at low RPM or idle, the cause could be a failing O 2 sensor. What happens is when the engine achieves the desired rpm's, the governor closes the throttle. We tried a known good quadrajet off another car that was running fine and it still did the same. It looks like a diaphragm about the size of a fist and will be located next to the throttle body, connected to the PCV valve. 5 again and get good idle on 2 counterclockwise screw. The AAR on the vanagon is a common VW aircooled part, so you don't have to shell out the big bucks for one from a vanagon parts supplier. Note I'm talking about the idle speed adjustment, which holds the throttle butterfly slightly open - I'm not talking about the low speed mixture screw. Nobody likes Chris Brown. could be needle bound or stuck partiallly closed,needle could be not properly seated on float arm,dirt or blocked high speed jet. When your engine stalls, it's not only bothersome, it can cause unnecessary wear to your car, or it can even be dangerous. It turns clockwise to lean out and counterclockwise to enrichen. Once you look inside a throttle body, you will probably be surprised at the dirt, gum and varnish that have accumulated there over time. When an otherwise properly functioning weed eater sputters and stalls, it can be frustrating and add time to your chores. I got it back to the house in one piece no issues. It may appear to work but when the weather gets cold, a high idle will result. A carburetor has a lot of parts in it that consist of “soft” materials. Start the engine and adjust from there. With the engine now thoroughly warmed up, allow the engine to idle for 30-60 seconds. Start up the engine at 1/4 to 1/3 throttle as previously done. I'm not sure which engine design is in the particular bike, but some had a timing chain that would slip teeth and go out of time. Once you have the CO set plug your O2 sensor back in and road test the car. Very difficult to get an idle speed that works when decelerating (either revs high at idle. Although the main things have been checked, filter, carb, etc but all seem fine and still no luck in getting her to stay going. I put fresh gas in it and kicked it over and let it run at idle for about 10 minutes. Vibration or hitting waves typically contributes. Re: Mercruiser 3. Depress the trigger and check the acceleration of the engine. You will find the best deals on 2 Hp Witte Throttle Governed Gas Engine Motor Hit Miss Crank Guard and other equipment here. When air enters the engine that hasn't passed through the AFM the engine doesn't know its there and will run lean. If the ISC valve is gummed up with fuel varnish or dirt, it may stick, preventing the engine from maintaining the proper idle speed when the throttle closes. At the engine, determine which cable is throttle and shift. Hi everyone I just purchased my 1990 244DL last week and it randomly dies when starting up the car. I even made a new gas/oil mix with fresh gas. The loss of 25% of the engine's power output is the equivalent of a horse trying to run on three legs. It seems to idle fine but whenever I give it the smallest amount of throttle is dies. Troubleshot and found a bad rectifier. but same, i feel the engine so rich while running low. 7L) engines. Unplug the IAC. As the throttle opens, additional fuel/air mixture is delivered via the progression holes (#12, red). The IAC can become sticky after time and will cause the the engine to surge, rev or stall the engine. The idle (pilot/lo) circuit in the carb is gummed up. com I have a John Deere mower with a liquid cooled Kawasaki engine which has approx 500 hr. I can start the blower fine, and it idles without any trouble, but when I open the throttle beyond about 20%, it starts sputtering and dies unless I lower the throttle back down. But now, when I go out to start it, it will turn over, start, but will only idle, it will shut off when you give it gas, The quad will turn over (but slower), restart, but only idle, and once again, die when you give it gas in neutral. My engine stalls or almost stalls when I come down to an idle. Your Engine just started acting up and you don't know what to do. The drawing below represents the most common design: a basic "bowl and float” type carburetor with adjustable valves. It was very noticalbe. Clean your carb and spray carb cleaner in all small passages, make sure air can flow through all ports no matter how small. Chainsaw will idle but won't rev. The engine is a 1969 350 chevy. We tried to get home as best as we can but did hit shallow water. Another scooter I accidentally made a small hole in the diaphram on top of the carb. tried to shut er down with the kill switch, the motor would not stop, turned the fuel off, and eventuall turned up. Spray anything flammable into the intake, and it revs. It should be getting air, with this warm weather now if I got snow in anything it should have melted. Idle problems may originate in a worn out component, a. Furthermore, if the throttle body is extremely dirty, it may allow so little air to pass by that the engine will flood (too much fuel in the cylinders, thus the engine won’t start). - Answered by a verified Technician. It will crank over, and start if I have my foot in the pedal, but won't hold idle after I let the gas off. Unfortunatley I can't run my car this way because there is no mas input to ecu and when i step on the throttle, it. My car idles fine just sitting but when I come to a light and push in the clutch to stop, the RPM's will fall and over shoot my idle (850) and the car almost stalls and then the IAC tries to recover and it surges for a few times trying not to. The engine starts and idles fine, but when I throttle up it dies within 30 secs. Metal parts should be lightly coated with oil to protect them from rust and corrosion. Check your front brake pads for signs of complete wear. If the engine catches or starts for one or two seconds when you spray the fluid, then. 2) Fast idle RPM incorrect (too slow) 2) Speed up the fast idle to factory specs. Running smooth even at low idle with the blower engaged and moving forward. With or without a distributor, erratic idle (including high idle speeds) can be caused by a faulty throttle position sensor (TPS) - a common problem (see diagnostics below). it idles the dies when i twist throttle. Mass Air Flow Sensor Connector - 1990-1994. The most common problem I see with the engine is it's inability to idle. If the noise does continue, check with a good mechanic for correct diagnosis. Idle Air Control System: All engine idle speeds are controlled by the ECM through the idle air control (IAC) valve mounted on the throttle body. 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!). With the engine now thoroughly warmed up, allow the engine to idle for 30-60 seconds. 5r that I just got about a week ago which I purchased used. my 95 blazer when coming to a stop and braking it idles high and rough sounding and it sputters and will clink and clank as stoppung and almost dies no engine light on what could be causing this. Idle fuel (small holes lower than the slots) is adjustable, and the main jet (higher throttle than the slots) is adjustable. The truck starts fine and idles fine but after about thirty seconds starts to puff white smoke. If your carburetor contains these screws, proceed below. When your engine stalls, it's not only bothersome, it can cause unnecessary wear to your car, or it can even be dangerous. Engine Issues: Bike Dies when given throttle? Just wanted to get some opinions on an issue I am facing on an '08 Ninja 250R. It starts semi-fine after adjusting the HSN a bit and idles smoothly, but when I give it enough throttle to get it going it just stalls out. I cleaned the carbs, changed the spark plugs and gave it fresh gas. If the engine bogs it usually means your mixture is too lean. Once that is set good, adjust the idle speed screw in or out until the engine idles smoothly and the head is not turning. New posts New media New media comments New resources Latest activity. Stator, ign switch, solenoid all tested fine. Skip to the section that applies to you: Engine Idle Is Too Low Or Stalls or Engine Idle Is Too High. Pull throttle full on (after warm up) and adjust H for high engine speed, but 4-stroking that smooths out immediately when cutting. 3) Check for vacuum leak. It happens randomly and it does not matter whether the engine is cold or warm. If it races when u spray a certain area that's the issue. Re: Engine idles fine,but DIES if you throttle it up? Well,its just a "crutch" to get by for the time being. I used to just use brake cleaner every once in awhile and it really helped, but this time i used WD-40. Adjusting The Idle Speed And Mixture. It has a rough idle when cold but will run after it gets warm. I was driving a 96td one day on the highway going about 60 when the engine just cut out for about 6 seconds. The idle is set to 800rpm. Problem is engine starts and idles fine but as soon as you give it gas it dies everytime. Adding any throttle via the screw or the the throttle cable just makes it die faster. It happens randomly and it does not matter whether the engine is cold or warm. The idle is set to 800rpm. You can verify this by applying throttle then choke - which richens the mixture of course if the bog goes away then you have too lean of a mixture. With this problem, the scoot will start and idle fine because the main jet is closed anyways at idle. I thought it was transmission at first or mayber the torque converter. That should help stabilize the idle. New battery, replaced round fuses with contemporary plug in fuses. No matter how long I let it warm up it still stalls when I try to use it. won't restart for hrs. Quick Links Solving Automotive Idle Problems Home Honda Idle Issues, Hunting Idle Idle Speech Idle Speech, Page 2 I get a TON of questions about Honda idle problems so I've put together this article to help you should you run into a rough idle on your Honda. Each year I change the plug & air filter, plus when I have finished using them I drain & run them dry. When I let go of the choke, it moves inward (choke off) by itself and the engine dies. If the car is stalling while accelerating at any given temperature happens, the possible problem is a bad throttle position. I tried to get the truck back to me when it stalled in the road. Failure of this device can cause the engine to idle too high or the engine to run lean. The small engine cannot lift the large air valve quickly or as high as a larger engine will. Now release the throttle and watch the gauge as the speed drops. In all my googling, I haven't found a description of quite these symptoms. New posts New media New media comments New resources Latest activity. If I leave the choke closed it will run at full throttle, but very lean, so I am pretty sure it is a fuel problem. My check engine light does not come on when I turn the key on. • (5) Start the engine and warm it up. Visually verify that the fast idle lever is in the run position -- down instead of up. A rich fuel mixture can cause an engine to “load up” at idle, foul the spark plugs, and also lack power or run sluggish. It will idle but shut off when. if it HAD proper spark (one with HEAT and not just high enough voltage to jump a gap and LOOK impressive),it would fire a plug gapped at. I did an amateur tune up on it, consisting of a new engine air filter, a fuel system additive, a spark plug cleaning and regapping, and a throttle body cleaning. No upgrades just bone stock carbs. I received it second hand as a gift, but it has only been used a handful of times. For example, on Tecumseh TVS, LEV, TVM, TVXL and other similar engines, the governor arm rocks in the counter clockwise direction to close the throttle to idle. You should also check to make sure the spark plug gap is set correctly. In this post I’ll explain the process of rejetting your carburetors in 3 simple steps: Main adjustment (main jets) Fine adjustment (gas needle + air adjustment) Stationary adjustment (air screw / fuel screw) Before you start. 1) Incorrect choke pull-off adjustment. Start by loosening the bowl screw and allowing the fuel to drain from the bowl. Stihl FS55 Trimmer Stalls at Full Throttle My Stihl FS55 idles fine but will stall at 3/4-full throttle. If it races when u spray a certain area that's the issue. At full throttle (not just the lever, but the throttle is all the way open on the carb itself), the motor runs smoothly but at about high idle speed. 4 to 1 air/fuel mixture and at 3000 rpm cruise mixture CO reading of. Re-start, same thing, choke in, choke out, no change in behavior. fire and start. I was driving a 96td one day on the highway going about 60 when the engine just cut out for about 6 seconds. if the engine runs at full speed you should be able to richen the mixture and notice a drop in rpm's or it will shut down. When you let the accelerator pedal up for coasting down or during shifting, then reapply the throttle, you may see a large puff of white smoke out the back. Components in the fuel, ignition, emission and other systems should work correctly. Now remove the float hinge pin, the float, and the metering needle. The whole procedure shouldn't take too long though. You could just use the trim buttons on the OpenTX: Idle adjustment knob for nitro helis - HeliFreak. Hello, I have a 2000 honda recon manual shift. The jet needle system for 1/4 to 3/4 throttle. Engine rough idle problems arise because car engines are demanding. Re: Outboard dies when throttling up from idle I was looking to 'upgrade' my 5 year old (minimal usage as tender motor) Yamaha 3hp 2 stroke for a Mercury 3. The range for cylinders 1,3,4 is 1 - 3. 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!). Tuned for maximum vacuum which is a steady 20 inch Hg. The idle speed is controlled by three methods: The cold idle value, which is located under the throttle plate. It starts up fine initially and idles fine. Although the main things have been checked, filter, carb, etc but all seem fine and still no luck in getting her to stay going. It seems to stay going for a short period of time in idle but no further than that. Set the mixture at idle (Adjustable on 2-needle carbs only). The engine has been running great, the only problem is that it backfires sometimes when shutting it off. it stalls when i put it in gear 50% of the time, it i difficult to get on the trailer on the boat ramp. I prime it, start it with choke and let it idle, idles fine, hit the gas past 1/3 throttle it dies like it's fuel starved. My bike (04crf250) will idle perfectly,but when i give it gas it seems to be fine for about 2 seconds and then the revs drop way down or the bike shuts off depending on how long/much throttle i give it, and it wont start when the choke is on. The bike hasnt been running to my knowledge for 4-5 months. Flow test carb to check jetting. First thought was to pop the hood and look and listen for vacuum leaks which we did as this would be the most common cause of this idle and surging condition. I feel that its as soon as you try chucking pet through it dies. Opening the throttle screw will allow more metered air past the throttle body when the engine is cold and can solve the cold idle problem, but will also cause your engine to idle high when warm. If I leave the choke closed it will run at full throttle, but very lean, so I am pretty sure it is a fuel problem. A good rule for any engine is that at very minimal throttle opening (idle) the burn rate is slower, so more advance is required. The tiny thing that keeps your car working, often falls prey to regular wear and tear, and therefore must be taken care of. Recently, I cleaned it up and drained the old gas out of it. OK, so I've got my engine idle portion tuned well in my opinion. Fixing Idling and Driveability Problems on Chrysler, Plymouth, and Dodge cars and minivans. Based on the problem description, the carb is not likely allowing gas to pass through the jets. Un-plug IAC while the engine is running, if it stalls turn idle screw 1 entire rotation, re-start staab throttle, continue this until it idles without the IAC plugged in. I changed my oil due to the gasoline in there, now my bike will only startup with the choke, then it dies when given throttle. Once again, should be real easy to chase down the problem. Remove the intake snorkel, have someone hold the throttle wide open for you and scrub the back side of the throttle plate and surrounding bore with an old tooth brush and some carb cleaner. Under the hood, I can move the throttle shaft to fully closed with my hand without much difficulty, but can't do that at a traffic lite. I doubt this is part of the problem, but in removing the tank, I had to destroy the fuel level float. Each year I change the plug & air filter, plus when I have finished using them I drain & run them dry. If the car idles rough or cuts off at low RPM or idle, the cause could be a failing O 2 sensor. If your ignition timing is way off or if the automatic spark advance is stuck. Engine idles fine, stumbles and backfires when under load my terramite with a Briggs and stratton 16 hp cast iron engine has been converted to run on a car coil. Things I have done: Checked for injector operation. Fuel in the spark plug hole poured, and it starts and runs for 2-3 seconds with smoke, then dies. The drawing below represents the most common design: a basic "bowl and float” type carburetor with adjustable valves. My truck idles fine but as soon as I give it gas it dies (2000 Ford F-350 Super Duty) when I started my truck it seemed to idle just fine but as i gave it some gas it fluttered. As a starting point the idle speed for a modified engine on Webers is between 900 and 1100 rpm. It idling could mean that it's sucking air, and can compensate at idle but not when the throttle is open. This small amount of combustible mixture burns very quickly, so for maximum efficiency, the spark needs to start when the piston is very near top dead center. Carburetor adjustments made on a cold engine will be too rich when it reaches normal operating temperature. and i would assume its getting spark since i replaced the spark plugs and a bad coil and the car idles fine. At idle, your engine is turning relatively slowly, let’s say 1000 rpms. i tried to restart it and get it running but it wouldnt. But then I rented a Wacker trash pump with a honda engine, and it would also oscillate when in the full throttle position whenever it lost prime. by Kyle McFadden. Also when it stalls at idle when it is hot if you prime it 15 times (you can't flood this engine) will it restart without holding the trigger at WOT? Open throttle to start even when cold or just prime and pull? If the saw starts at idle and you don't accelerate it will it stall?. The spark arresting screen in the muffler should be cleaned or replaced with a new one. Remove and clean the screen that covers the Exhaust. First, what is a throttle body and why does it need to be serviced? A throttle body is an electronic device that operates the throttle valve. They both start but as soon as they get hot they die. Why does my moped start and then dies even when I pull on throttle? by Chris (Sorrels) When I try to start my scooter, I get it started but when it starts, it seems as though it just idles for a while and then dies. I have a 1997 Esprit that has an annoying problem. That would probably be an EPC circuit failure. But the noise while driving under the car that you say sounds like a tick or slight knock could be an exhaust leak coming from a broken exhaust bolt or cracked manifold. MIKUNI CARB I believe its a carb problem because when i give it gas white mist/smoke shoots out of the carb also every one and a while it shoots out white smoke out the exhaust. You can verify this by applying throttle then choke - which richens the mixture of course if the bog goes away then you have too lean of a mixture. Allow the engine to run at idle for 30-60 seconds; then stop the engine. The position of the throttle valves determines how much air and fuel can be drawn into the engine to control engine speed. The engine has no problem jumping up in rpm when it is tapped but once the throttle is quickly released from being pressed quickly it doesn't return to idle it just dies or sputters and picks back up to idle. USUAL CAUSE The usual cause of abnormally high idle speeds are vacuum leaks or an inoperative idle speed control motor. Engine started, noticed ammeter fluctuating on the high side, (not normal). It starts easy and idles fine, but after I run it at moderate speed on the bench or on the dirt or pavement it dies immediately and won't idle. MacFarlane wrote that many engines had/have two converters in series. ThrottleControl. and i would assume its getting spark since i replaced the spark plugs and a bad coil and the car idles fine. Remove the intake snorkel, have someone hold the throttle wide open for you and scrub the back side of the throttle plate and surrounding bore with an old tooth brush and some carb cleaner. Start up the engine at 1/4 to 1/3 throttle as previously done. Opening the throttle screw will allow more metered air past the throttle body when the engine is cold and can solve the cold idle problem, but will also cause your engine to idle high when warm. Hello, My vehicle is a 2000 Ford Expedition with a Triton V8 engine and mileage of 162,000. Center-mounted carbs need a RICHER (larger) idle jet, since the carb is so far from the cylinders and the fuel condenses on the way there (keep your manifold pre-heater). Start the engine and shoot starter fluid or wd40 at the crank seals and the base gasket. True? Now for this year starts with the few presses on the bubble primmer and a few pulls. There will be a tube extending from the base of the carburetor. If your engine pulls 15"Hg but your vacuum advance doesn't max out until 20"Hg then you may have an unstable idle. The bypass screw is located under a black rubber plug on top of the throttle body. Release throttle and adjust L for fairly smooth idle, but rich enough to allow the engine to 'follow-the-throttle'. The idle air control will be located on the side of the throttle body. It could be the throttle position sensor or the idle air control valve. In fact, one should expect a well-tuned high performance engine to "pop" and "crackle" when the throttle is closed at high rpm. Replaced fuel filter. Engine idles fine, stumbles and backfires when under load my terramite with a Briggs and stratton 16 hp cast iron engine has been converted to run on a car coil. She fires right up and idles beautifully. There are no air leaks or electrical faults. For stopping the engine, the black lead wire from the coil should be grounded to the engine body, or the throttle valve should be closed completely. Start engine and place throttle in the idle position. If 2 or all 4 of the slots are over-exposed, it changes the effect of your idle fuel, and indirectly impacts your acceleration fueling. Clean your carb and spray carb cleaner in all small passages, make sure air can flow through all ports no matter how small. It has new plugs and wires, new distributor cap and button, new air cleaner and fuel pump. efco mt3700 will idle but throttle kills it. As soon as I try to give it a little more juice or jab the throttle, the falls on its face, sometimes revving back up for a second before bogging down again. Unplug the IAC. The EGR valve should be closed when the engine idles, but if it sticks, it will cause an uneven idle and worsen the gas mileage. The bike hasnt been running to my knowledge for 4-5 months. and i would assume its getting spark since i replaced the spark plugs and a bad coil and the car idles fine. Fuel Filters. 3) Engine running too lean because of vacuum leak or dirty jet. A tachometer can be used to set it to specifications but there is no risk is just adjusting it to idle smoothly. The computer looks up an adjustment percentage of -2% (see table 4). That would probably be an EPC circuit failure. However, issues while revving may be a sign of a failing throttle position sensor. It doesn't take much debris to allow idle but falls on its face when given throttle. I can start the blower fine, and it idles without any trouble, but when I open the throttle beyond about 20%, it starts sputtering and dies unless I lower the throttle back down. 3) Check for vacuum leak. , 1/8th turn) and test again. With this problem, the scoot will start and idle fine because the main jet is closed anyways at idle. The throttle return spring/mechanism is working properly. Clean your carb and spray carb cleaner in all small passages, make sure air can flow through all ports no matter how small. This is a 2005 Vento Triton R4 , it set outside for a year, I did the normal things, Dumped the gas , blew out the lines , cleaned the Carb, replaced the spark plug , but all it will do is Idle , as soon as I give it throttle it bogs down and dies. Why does my moped start and then dies even when I pull on throttle? by Chris (Sorrels) When I try to start my scooter, I get it started but when it starts, it seems as though it just idles for a while and then dies. 0L idles but when you engage throttle it cuts off There is a strainer in the carb inlet, another filter in the fuel pump. When I run it in my driveway it also seems to run fine when I rev it both in neutral and in gear. Opening the throttle screw will allow more metered air past the throttle body when the engine is cold and can solve the cold idle problem, but will also cause your engine to idle high when warm. All STIHL gasoline-powered engines can be used with up to a 10% (E10) blend of ethanol in the gasoline/engine oil mix. Find the answer to this and other Small Engine questions on JustAnswer We use cookies to improve your experience. Some engines will seem to surge when there's no load because when the drive, auger (if a snow blower) or blade (if a mower) are disengaged, the governor will keep it from reaching full throttle. The most common problem I see with the engine is it's inability to idle. Caution: a “good” idle speed when half warmed up will be too high when fully warmed up, so you must accept the inevitable requirement for some “throttle nursing” until the bike is fully warm. In combustion engines , idle speed is generally measured in revolutions per minute (rpm) of the crankshaft. If I throttle up while starting its fine and as long as i am in gear it runs fine but when i come up into neutral the engine will shut off. Blower: Engine Will Idle But Dies At Full Throttle. 1994 Ranger 4.