My JD 777 ztrak will not start.Replaced inline filter,fuel pump. Eng turns over but will not fire off. Pulled the fuel line off and no fuel. blew air in line and started flowing but then stops again.

could mean filter clogged

Blocked fuel filter

Does not turn over or does not start? Does not turn over usually means a bad battery or starter. Or connections which you have already checked. There may be a fuse block or inline fuse as well. Does it have a manual pull start as well? Does this turn over the engine or is it siezed up, low/no oil.
Turns over but does not fire usually is spark or the fuel. Back firing would guess spark plug or carberator (air fuel mixture) If it turns over but does not fire, try putting in some Seafoam fuel system cleaner. This will get the varnish-gunking stuff out of the carb. Mix in your tank, turn over quite a bit to get it pulled into your carb bowl and into some of the carb port holes. Let it soak a while and then turn over again every so often to pull in new cleaner. If it starts at some point it will stink a little while burning the cleaner in the tank.

Make sure you have check the old fuel lines and and air vacuum lines for pin holes and cracks as well. Change the plugs. Make sure the air filter is clean. Change the fuel filter. Does it fire if you shoot starter fluid in the carb air intake, this would suggest a fuel issue, such as dirty carb, bad fuel line or fuel filter, or fuel pump.

Okay, you need to make sure the fuel pump is getting power and that you have the lines hooked up correctly. Also, when you replace fuel pumps you need to remove the air cleaner and use starter fluid to get the engine started.

When it quits remove the fuel line from the fuel pump to the carburetor and check if the pump is pumping gas while you turn the key to the start position with the brake locked. You could have a bad ignition coil.

Do you have more than 4 gallons of gas in the tank? Some models won't **** to prime with less than that in the tank. This is mostly an issue when there is air in the lines. There is usually a screen filter on the pick up, but blowing that out should have taken care of it at least for a few days. Another possibility is a pinhole leak in the line between the tank and the pump. That lets the pump **** air, which will not let it **** gas. There could be a larger in-line filter between the tank and the carb filter. Let us know if you find out what it is.

If the fuel pump is working correctly then the problem is between the tank and the pump. run a fuel line from the pump to a gas can. If the pump is working it will siphon the fuel into your filter. If the pump is fine then there is blockage, broken fuel line (sucking air), or something blocking the pick up inside the tank.

My idea would be to replace the coil to that plug

Jim Kite paris, il

I would suspect the fuel pump. Those thin diaphragms wear out every few years. But you can also make sure there is no obstruction in the line from your tank at the same time!