Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

 

My 11 month old MTD 9.5 hp snow thrower will not get gas.  It wont prime gas into the carb, or get gas while running.  It will start with gas or starting fliud put in the spark plug hole, but will run only 5-10 seconds and die.  I removed the gas from the tank, sprayed through both hoses ( from fuel tank and primer) to clear, inserted new gas, but no luck, .  Any clues?

what engine is it tecumseh? remove the the float bowl and see if there's fuel in the bowl and if its full then make sure the main jet is not blocked (blow air throw it) if the bowl is empty remove the fuel line at the carb and see if fuel there's.

I had a problem with my engine and it turned out that the little tube that connected the primer bulb to the carburetor was cracked at BOTH ends, a new length of tubing and its worked well ever since. The guy at the L&G said that alcohol in the gas causes the tubing to stiffen and crack fster than it used to.

Do as NIper said but if there is NO fuel in the float bowl, check the float needle valve to ensure the needle is moving freely.  Also check the float needle seat for varnish or debris.   You might also want to look for water or ice in the float bowl.  Sometimes, when you dump the contents from the float bowl, it may contain a fair amount of water.  So when you empty it, dump it into a clear container to see if there is water and dirt in it.   If you're unfamiliar with the workings of carburetors, you might want to download a file with illustrations explaining carburetor basics.   Does your machine have a fuel valve?  If so, is it open?

Yes nipper it is tecumseh engine.  Went out to garage and the hose to the primer bulb looks new, and did not have cracks.  I hear the air when I pres the primer but no fuel pumps up.  The bowl is empty, and not sure what the float is.  But if I spray a shot of starting fluid in the bowl it will fire up and run just long enough to burn off it.

And nipper what or where is the main jet.  is this the line from the gas tank to the carb?  Borat dont know where-abouts the "float neddle valve" I'm going to serach for  illustrations explaining carburetor basics on the web shortly. But the engine does not have a fuel shut off valve on this model.

If you  have no fuel in the float bowl, your float needle is likely stuck.  The float is the device that controls fuel flow into the float bowl.  The float needle is the device that is actuated by the float via leverage that allows fuel into the float bowl.  When the float is lifted by the incoming fuel, it forces the float needle up to prevent more fuel than necessary from entering the float bowl.   It's not much of a piece.  Probably around half an inch long with a point  (sometimes made of neoprene) on one end.  The point is the valve end that sits in the seat to control fuel flow.  Be very careful when working with carburetor floats.  They can be very temperamental and do not take kindly to force.  Be very gentle.  The float is usually held on a pivot with a straight pin that isn't normally difficult to remove.  You can slide the pin to one side, carefully pull out the float.  Opposite the float side of the float device should be a short, usually brass protrusion  that actuates the float needle.  It should be sitting in the float seat.  Be careful because it's small an can easily drop out.  If it doesn't immediately fall out, that's probably the source of your problem.  Gently pull it out then carefully clean the float needle seat orifice with a very thin wire or straight pin.  If the carb is off of the machine, put a piece of fuel line on the fuel inlet and blow into it.  If air passes through, you should be good to go. 

rte29 wrote:
make sure there is fuel going to the carb (detach fuel line from carb and check for fuel) the float is round and should hang down when the bowl is takin off, the needle is attached to the float by a spring clip, when you move the float up and down that is what controls the fuel in the bowl, so if you take off the bowl and the float is hanging down then there should be fuel coming out, if not then you have a problem from the carb to the tank, u could take the fuel line off the carb and blow air throw it to see if its blocked make sure you take off the fuel cap.

Thanks nipper99 and borat,  the float needle was sticky, I cleaned it and cleaned the seating area around it with a paper clip.  Now it primes up gas fine when pumped.

Put it back together and it fired up.  Thanks again fellas for the carburetor tips,........learned a lot.

Sounds like either you got some bad gas with some crud in it or the tank was sitting partially full for some time without stabilizer.

Glad to hear its now working.

If it doesen't have a fuel shutoff you should really put one on. They only cost a few bucks and can save you a lot of aggravation.. You should shut the valve EACH TIME you use the machine before you put it away. That way if the float sticks or the needle and seat are damaged gas won't be able to keep flowing by gravity and spill out of the carb into your garage. Definitely a fire hazzard not to have a fuel shutoff!!!

Marc