L120 Won't Start without priming carb

[pjd822]

My John Deere L120 won't start without first removing the air filter and pouring a bit of gasoline into the carb. Once started, it will restart for the remainder of the mowing session without priming. Any ideas what the issue might be? Thanks in advance, Paul

 

[forgeblast]

Is the fuel filter clogged? or the hole on the top of the gas cap?

 

[sam5570]

that is such a minnor problem that it could be a little of several different things. to start with most of the time when the fuel runs back out of carb it;s a air problem either the gas line has cracks and the air getting into system allows gas to drain back out of carb. it could be a carb diaphram dried out not allowing to prime. cold be the chock flapper in carb either worn or not closing all the way to cerate suction for fuel. but like i say this is hard to pin point simply because you can go all season and not have to do it again. and it be very hard to find out for sure cause you only get one chance a year to see if what you done fixed it or not. hope this helps

 

[pjd822]

Is the fuel filter clogged? or the hole on the top of the gas cap?

Not that I know of, but I will recheck.

 

[pjd822]

The problem isn't just the first time I try to start the mower in the Spring; it happens the first time I try to start the mower with each use.

that is such a minnor problem that it could be a little of several different things. to start with most of the time when the fuel runs back out of carb it;s a air problem either the gas line has cracks and the air getting into system allows gas to drain back out of carb. it could be a carb diaphram dried out not allowing to prime. cold be the chock flapper in carb either worn or not closing all the way to cerate suction for fuel. but like i say this is hard to pin point simply because you can go all season and not have to do it again. and it be very hard to find out for sure cause you only get one chance a year to see if what you done fixed it or not. hope this helps

 

[sam5570]

My John Deere L120 won't start without first removing the air filter and pouring a bit of gasoline into the carb. Once started, it will restart for the remainder of the mowing session without priming. Any ideas what the issue might be? Thanks in advance, Paul

correct me if i'm wrog but i understood you to say here that it starts fine the rest of the mowing season. ok now if you have to prime it each time you probably need to replace your gas line from tank to carb. it's probably dry roted and has cracks thats allowing air to break the vacum on the fuel. thats the first thing i would check. something is allowing the fuel to drain back when mower is not running so chack everything connected to that.

 

[jenkinsph]

correct me if i'm wrog but i understood you to say here that it starts fine the rest of the mowing season. ok now if you have to prime it each time you probably need to replace your gas line from tank to carb. it's probably dry roted and has cracks thats allowing air to break the vacum on the fuel. thats the first thing i would check. something is allowing the fuel to drain back when mower is not running so chack everything connected to that.

If you reread carefully he said " remainder of the session" not "remainder of the season".


I had problems with my L130 hard starting with each session too, I installed an inexpensive electric fuel pump inline connected to the key switch. Now I turn the key on and wait a couple of seconds and it starts up instantly. That saves a lot of starter wear and tear and makes my life easier too. Pump was about $30 at NAPA.

 

[deerseeker001]

i had the same problem with L130 it turned out to be the hole on the top of the gas cap.its a vent hole.

 

[sam5570]

If you reread carefully he said " remainder of the session" not "remainder of the season".


I had problems with my L130 hard starting with each session too, I installed an inexpensive electric fuel pump inline connected to the key switch. Now I turn the key on and wait a couple of seconds and it starts up instantly. That saves a lot of starter wear and tear and makes my life easier too. Pump was about $30 at NAPA.

jenkinsph thanks for pointing that out old ignorant me just scaned over and thought it said something that it didn't. my bad sorry pjd hope you got mower fixed.

 

[Larry Barnes]

MY L120 won't start until I've run the starter way too long and too many times before it even pops a bit. When it begins to pop, I know that it will start soon. I'll guess it's losing it's prime and will look for hose gas leaks, etc. My question is is the gas cap supposed to be vented? Mine does not appear to be vented. There's no hole in the top of the cap. It's solid. Do they have an internal vent? Or are they supposed to be air tight, to pressurize the fuel system a bit?

 

[tomplum]

Yes. L series are vented via a center hole. Welcome.

 

[Richard001]

Yes. L series are vented via a center hole. Welcome.

So what should Mr. Barnes do ?

 

[RandyT]

So what should Mr. Barnes do ?

Two things. Make sure he has the correct cap since it appears that model should have a vented cap. And the other thing is make sure the choke is closing completely. If that mower has the single throttle/choke control there is a good chance that the throttle cable has slipped in the clamp at the front of the engine and is now not completely closing the choke.

 

[Robin Veerman]

All of the above….maybe try running it with the gas cap loose? but maybe check the valve lash too. Difficulty starting a cold small engine is one symptom of tight/no valve clearance. Google the clearance or check your manual for your specific engine.

 

[WranglerX]

Late to the thread, but it may be bad fuel line between tank and fuel pump.... I had problems with hard start and after many hours of chasing things discovered fuel line had macroscopic holes in it and was drawing air instead of fuel.... Replaced fuel line between tank and fuel pump and problem solved....