Fuel flows well from tank ,through filter, into carb.Bottom of carb bowl is electrical connector (Fuel solinoid?) if i pull that off ,engine revs and then dies. I plug it back in and cranks over but barely runs seems to be backfiring pop-pop-pop with white smoke. This is a Craftsman LT3000.
This is second use of the year after sitting all winter.First use I blocked off some air intake and engine smoothed out. Thought I had resolved it then...
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Re: Engine runs like POP-POP-POP.Fuel solinoid?
Hi..my name is Keith...this is kind of a hard one to answer...when im not there...but i would suspect weak fuel..i would drain the tank and put fresh in and a new fuel filter..and if that dont help..then you might need a carb cleaning or overhaul..i hope this has helped..if not..write me back
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Everybody had a crack at this problem, another thing would check is these engines sometimes have a primary fuel filter inside the tank itself. Drain the fuel and gently blow compressed air back through fuel line towards tank then rinse the tank out with fuel, refill and try run engine again
Engine hunting is usually down to fuel starvation, this can be dirt in the carb, or the fuel pump is not working correctly, or the anti fire solinoid on the base of the float bowl is not working correctly, you can check the fuel flow from the pump by removing the fuel hose from the carb, place the hose in a suitable container now crank the engine, there should be a good flow of fuel, if so replace the hose, now remve the fuel solinoid from the bottom of the fuel bowl ( place a suitable bowl under the carb as there will be a flow of fuel) switch the igntion on, there should be a click and the small pin in the centre of the solinoid should retract into the housing, if this is ok then there is dirt in the carb so you will have to clean the jets in the carb itself.
There are 2 different enigines on these depending upong your actual unit model number.
One had a Subaru 175 cc engine and the other was a Honda engine. For carb specifics I need the ENGINE model number. Either way... here is what you need to do:
1. Fuel selector off.
2. Remove main fuel line from the carb.
3. Use a spray can lid and check FLOW. It should fill the lid in under 8 seconds. (Feul selector OFF now) If you do not have good fuel flow here you need to inspect the tank exit port, in line fuel filter if used and the sediment bulb under the fuel selector for debris
(GOOD FUEL FLOW NOW)
4. Remove the float bowl by unscrewing the bowl nut from the bottom of the carb. NOTE positon of gaskets as you remove float bowl. Use carb cleaner and direct a spray hopefully with mini extension tube of the carb nozzle into the center of the threaded area of the bowl nut. (This cleans main fuel jet orifice / pin hole) Then spray carb cleaner using mini nozzle extension up the flat side of the float needle until carb cleaner exits the main fuel line connection. Last spray from the main fuel line connection to the float needle (reversed spray)
This usually removes any debris from the float bowl. main fuel jet and main fuel manifold Reinstall the main fuel line.
- Turn on the fuel selector and use the spray paint can lid under the float to catch fuel. It should fill in 8 to 10 seconds to the point your worried about over-flow.
- GENTLY lift the float needle to the level position. FUEL MUST STOP.
- Lower Float to resting position. FUEL MUST FLOW so that it would fill the spray paint can lid in 8 to 10 seconds. (FUEL SLECTOR OFF)
Clean the bowl nut and reinstall the float bowl. Turn on the fuel.. wait 30 seconds for the float bowl to fill completely and start unit. If it runs GREAT... If it only runs with the choke on you still have a fuel supply problem...i.e most likely the main fuel just in the threaded area of the bowl nut is still clogged. .
This should get you going. Thanks for choosing FixYa,
There will be an anti fire solinoid on the bottom of the carb bowl, the idea is to shut off the fuel in the main jet when the engine is switched off, you should hear a click as soon as the ignition is switched on, you can take it out and check that the centre pin goes in when the ignition is switched on. If it has an external vacume pump, it may not be working, these are fitted where there is no gravity feed to the carb from the tank, if the fuel hose from the tank goes to a component and then to the carb it does have a pump, pull the fuel hose off the carb and crank the engine, there should be a steady flow of fuel, if not check the vacume hose has not become detached, if ok replace the pump.
Disconnect the fuel line at the carburetor, then run the engine by priming the carburetor. If no fuel is pumped out of the line, then back up to the pump, and then to the tank itself (may be a filter issue). Is the fuel pump electric or run by the engine mechanically? If electric, you should be able to hear it running. A mechanical pump needs to be disconnected from the engine and operated manually to check it's operation. If the tank has a filter bowl with a screen in the upper part, the screen may be plugged--dig it out and wash it with spray carburetor cleaner. Once you get fuel flowing from the line at the carburetor, but the engine still doesn't run, then remove the carburetor float bowl, the float, and needle valve. The needle valve can sometimes stick closed, or debris can block entry of fuel into the carburetor. Check the jets for plugging as well. Hope some of this helps!
Hi and welcome to FixYa, I am Kelly. I have been working on small engines for over 40 years and this sounds like possibly a fuel starvation problem. Since you did not include an engine model or engine number & size, ths response is quite generic. Remove the float bowl and clean the bowl nut holes. Also with the bowl removed the fuel flow should fill a spary paint can lid 2/3 rds full in about 8 seconds. If you do not have this king of fuel flow then the problems can be:
1. A clogged fuel filter (If installed)
2. A glass fuel bowl on the bottom of the fuel tank or in line with the main fuel supply that is full of sediment.
3. An obstruction in the fuel tank outlet port (rust / debris, grass et al)
While the feul bowl is off remove the main fuel supply hose from the carb and check fuel flow. After you are sure you have a good fuel supply re-install the main fuel hose to the carb AFTER shooting carb cleaner into the fuel manifold connection. Also use carb cleaner and spray into the threaded area where the bowl nut screws into the bast of the carb. This is where the main fuel jet is located. You can use a small nail or tooth pick to clear any obstructions in the jet orifice above the threads of the bowl nut. Also spray carb cleaner into the brass tube in the bottom of throat of the carb (goes to jet orifice)
If you are having ignition failure that is heat or vibration related you will have to find out where the ignition kill wire is chaffing on the engine. If can be anywhere from the throttle control to under the flywheel. You just have to follow the wire from the kill switch point all the way to the ignition coil searching for a bare spot. An tidy electrical tape repair of a chaffed wire is ok. On some snow blowers I have had to cut the wire.. install a piece of shrink tubing, solder the 2 wires together and then skrink the tubing over the repair due to water intrusion from snow.
Sometimes... it is possible for a spark plug to fail as it gets hot. A new plug sould solve this problem. Also check where the spark plug wire passes through the air shroud for any signs of insulation break down.
If you need more help or have any comments just repsond here and I will gladly help you.
I always replace the air filter if its a paper element, and even if its a foam element I replace it rather than clean it. That said, engine stumbling is rarely and air flow problem - but it could be, so having a new filter assures no air restrictions.
I would drop the carbuerator bowl. On the bottom of the carb, near where the fuel line comes into the engine, should be a nut. Removing this nut allows the bowl to drop off the carb. Some engines the bowl screws off, you will have to look at the bowl. Often the bowl has sediment or sludge buildup inside. Cleaning the bottom of the bowl can prevent that sludge/sediment from plugging the intake tube. Even on newer mower models this is a common problem, the gas line tubing interior breaks down and the inside of the tubing can start degrading - ending up in the bowl as sludge.
After cleaning the bowl, I would add one ounce of fuel line cleaner to a full tank of fuel and run the entire tank of fuel. This will clean any deposits or "varnish" from the interior carb parts. Doing this and the first step will assure your carb is clean and functioning.
If that doesn't help, then I would look at the spacing between the magneto and coil assembly. If you want to do that I'd like you to write down all the model numbers and serial numbers on the engine nameplate, that way I can give you specific directions.