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How to Identify and Fix Common Gardening Problems ?

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Regardless whether they are being used for bulk fuel storage or they are located on a vehicle, diesel fuel tanks require a tank vent or tank breather, potentially both, for optimum equipment safety and performance.
The fuel tank may build excessive pressure due to a blocked vent. This could cause fuel to spray on occupants or bystanders when opening the fuel cap, potentially causing injury. Additionally, if an ignition source was present, this could create a risk of fire, causing injury and/or damage to property.
Symptoms: Upon filling your gas tank, when you start the car you may notice a bouncing, loping, or otherwise erratic idle.
Without a vent, the pressure would increase steadily, rupture seals and allow oil into the combustion chamber. A breather tube is part of a positive crankcase ventilation system that usually includes a one-way valve that prevents exhaust gases from cycling back into the engine.
Engines and moisture don`t mix, so getting rid of the harmful water vapor and any liquid water is important for keeping the engine safe and reliable. That`s done through the oil breather tube, a section of plastic or metal tubing that comes out of the engine and vents through to the outside.
Point #1: Vent pipe.

Bonus details: The vent pipe is there to relieve the vacuum created when your burner pulls oil from the oil tank. At oil delivery, when the oil gets put into the tank, the outgoing air goes through the end of the vent pipe and makes noise like a whistle.

The Fuel Tank Vent Cap is to be used on an above ground fuel storage tank`s 2” male thread to provide ventilation. These vent caps, which are designed to be fitted on to heating oil storage tanks, have a plastic mesh that prevents particles and debris from getting into the tank from this point.
The vent line or EVAP tube the comes from the gas tank is typically routed to the intake manifold. The intake manifold is where the air is mixed with the fuel before it reaches the combustion chamber.
A tank vent may seem like a small component of the system, but it is absolutely necessary. If there is a pump attached to the tank and that pump is drawing suction from said tank, it is imperative to properly vent the tank.
The breather tube allows fresh air to be pulled into the engine, after the air filter, ensuring debris and moisture aren`t pulled into the engine.
The vent line or EVAP tube the comes from the gas tank is typically routed to the intake manifold. The intake manifold is where the air is mixed with the fuel before it reaches the combustion chamber.

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I have a husqvarna 323L string trimmer. I stored it after running the tank & carb dry for about two years. I fueled it, then started it, & it ran for a minute then died like I turned the switch off. Since it would not restart, I found the fuel filter had broken off the hardened fuel line & it sucked gummy crap out of the tank & into the carb. Failing at cleaning the carb, I finally put a new carb on it & replaced the pump, hoses & filter. It has ran good till this year. I winterized it with stabilizer & left it with a full tank over the winter. The gas in the tank was gone when I got ready to use it this year. I filled the tank with premix, checked for leaks, then started it. It would run fine for about half a tank, start idling poorly (lean) then cutoff & refuse to restart till I refilled the tank. I finally found the tank had cracks & was letting pressure out of the tank & apparently this was causing the carb to lose it’s ability to siphon gas out of the tank. So I replaced the tank which came with new hoses & a filter, which I properly installed to the carb. It cranked right up, but when it runs a half tank, the carb quits sucking gas out of the tank. When I pump to prime the carb, it moves the fuel into the carb, but the pump never gets hard like it does when I prime the carb when the motor is cold. I have to keep refilling the tank, prime, & then it starts & runs until the tank gets about half empty. The new fuel filter is down in the gas tank properly, but It will not run after it shuts off until I refill the tank & prime. I’m baffled. New tank, new hoses, new filter, new carb, & I can find no leaks in the fuel system. It runs strong. The 323L is a two-stroke & it always cranks on the second pull from cold on a full tank. Any ideas?

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I bought a Poulan PPB100 at a yard sale for $20.00. I got it home and got it started and running but it leaked gas like no tomorrow. I took it apart to see what was needed and found that all the fuel lines were crumbling. I cleaned out the tank and cleaned the carb and blew it out with compressed air from a can (computer stuff). I replaced the fuel lines but I’m not sure if I oriented them correctly. There are two lines going through the tank. A very skinny one and a larger one. I connected the new fuel tank pickup to the larger one. I also don’t know if I got the primer bulb tubes correct. The string trimmer starts using the normal procedure but it only runs best at half choke. Turning the choke off makes it die. Also if I give it throttle too fast, it’ll stall and die. What else can I do? Are the fuel lines and primer tubes the problem?
ANSWER : This is an ongoing issue for users, and rightfully so. Small diameter line out of fuel tank (has filter in-tank on end) connects to the side of the carburetor that has the fuel pump….that is the cover without the hole in it. Other larger diameter fuel line out of tank connects to the longer nipple on the external purge/primer bulb. The bulb “pulls” fresh fuel from the fuel tank to the carb and then out of the carb to itself, where it then pushes any air/old fuel back into the fuel tank. The remaining larger diameter fuel line in this setup goes from the metering chamber (has cover with writing on it and a vent-hole) side of the carburetor to the smaller nipple on the purge/primer bulb. Years ago on 2-stroke trimmers, primers were not even used,…you choked the carb with a slide lever and gravity let fuel enter the carb from above…a few pulls, a “pop”…slide it off of choke and away you went.If the purge/primer bulb is on top of the carb…small line from carb body to small hole in tank with filter. Larger diameter line goes from the bulb on the fuel pump side of the carb to the larger hole in the fuel tank where the line is held in place with a nylon nipple connector that keeps the line from pulling out of the tank.
Please vote on this solution.

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I have a Husqvarna 235R trimmer. One of the fuel tubes going to the primer bulb cracked. I replaced the tube. At the same time I didn’t know that the tube from the carburator to the fuel tank was cracked also. I replaced that one also. I don’t know how far the tube extends into the fuel tank though. I couldn’t get the bulb to prime so I switched the tube connections (the one from the carb to the bulb and the bulb to the fuel tank) to the bulb. I was able to get the bulb to prime and start the engine but the engine will not stay at idle. So I swithced them back and cannot start the engine. Which tube does the fuel filter go on the one from the carb or the one from the priming bulb.

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I know this is a pretty old thread. But I have a 2004 Husqvarna 359 and it does the same thing. Has anyone found the cause of the problem yet. It seems to die from lack of fuel or too lean of a mixture only when the saw is hot. I have : removed the cylinder and found it to be scored very bad, i replaced the cylinder and piston, replaced the fuel filter, removed the carb and checked for debris, new spark plug, new air filter, changed fuel to a 32:1 just to see, all to no avail. I dont know how to test the ignition module, and I dont know if there is a way to test the cranck shaft seals. If any one can give me advise from here it would be greatly appreciated. Thank You, Brian in Spokane Wa.
ANSWER : I didn’t want to close the thread in case someone else had some ideas. We can still discuss this problem. Enter any clarification or additional information below the advertisements. HTH
Hoped Dolf would chime in.

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Have a craftsman 16″ chain saw 358.360260. Could not initially get it started after it had sat for a couple years with fuel stabilizer in it. When I went to use it the fuel had all evaporated and the fuel pick line was rotted. I replaced that with some difficulty but finally got it on. Saw still wouldn’t start. Replaced the fuel filter. Still wouldn’t start. Pulled the carb apart and cleaned and recleaned everything. Diaphragms were good and I didn’t adjust any of the mixture screws because as I said it ran fine before storage. Non of the carb passages were clogged. Fresh gas 40:1, good spark plug and good spark. Airfilter is good. Engine has maybe about 4 hours of total run time on it. It’s a ZAMA (?) carb. It will run for about 30 seconds when I manually prime it by pouring a small amount of fuel directly though the carb. When I was disassembling the carb the vent hose that goes back into the fuel tank seemed to have a small out of ?substance? in it which I cleaned out. It was right at the end the of the hose that goes back into the fuel tank and not up by the carb. It didn’t appear to be like your typical gummy deposits/varnish though. I hope it wasn?t some type of spongy check valve stuff that is supposed to be in there. That might explain some of my problems. Anyway, I also can not seem to get the primer bulb to fill. When I open the fuel tank, look in side and depress the primer bulb, air bubbles come out of the fuel filter. But when I let the bulb reexpand there’s no fuel that gets sucked up the hose. I can however seem to fill the primer bulb when the fuel tank is full and the chainsaw is laying on it?s pull cord side and the bulb is depressed a bunch of times. The saw will also start and run again for about 15 seconds then die. It’s definitely not getting/fuel and probably running out . Thanks.

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I have a poulan p3314 chainsaw. It has been sitting up for a while. When I started it, I could not get it to run beyond an idle. Every time I squeezed the gas, it quit. Finally, it quit and refused to start. I decided to put fresh gas in it and change the spark plug. When I emptied the gas tank, the fuel filter fell out. The fuel line had rotted. I contacted Poulan, and they sent a new filter and line. Their instructions were inadequate. First, it is difficult to tell where to attach the new line. there appears to be a fitting in the front end of the tank. There is also a piece of rotted tube end the back end of the tank.

1) where does the tube with the filter attach?
2) how do you go about attaching the new tube? Can the tank be removed? It seems like it might take a special tool or some nimble fingers to attach the new tube
3) would this have been the cause of the rough running and its refusal to start?

ANSWER : The ful line actualy disloved and the problem is inside the carburtator there is a valve that lets fuel into the fuel bowl and also shuts it off when its full the floats control it so its always opening and closeing that is stuck closed from the melted fuel line you need to clean the entire carburator out the neddle valve may have a rubber tip at the seal point so take care not to damage it ware it makes the seal but its not hard to do anyone with some common sence and a little mechanical abilitly can do them selves

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The fuel lines have rotted out of the edger gas tank. How do I fix or do I need to replace entire tank with new fuel lines?Since there are no male fuel line connections exiting the fuel tank and just two holes where the lines were, I guess I need to replace the entire tank and get a new one with lines already attached. Thanks.
ANSWER : No you can buy replacement fuel line but you must reconnect the filter in the tank that line goes to the bottom of the carby then out the top of the carby to the inlet on the primer then out of the primer and back to the tank.

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Fuel coming out of venthole on the tank
ANSWER : Since you forgot to mention what saw you actually have, it’s hard to answer but does it do it only after you have pushed the primmer bulb ???

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