Sounds like she picked up some debris within the latter part of fuel in the tank . Check out the spark plug if dry you have fuel restriction. Check for a fuel filter and see if there is any dirt , etc. Then if all appears good get some concentrated fuel cleaner remove the carb jets and spray some within the jets . Replace the jets 1-1/2 turn out from closed . Then add some fuel cleaner to fresh fuel mix let it sit for 20 minutes then start the unit as usual keep it running with full choke 1/2 choke until it will idle and rev up as normal . You probably will have to fine tune the low and high speed jets and idle speed once you get the unit warmed up . Let us know how you fair Dude !

Further to my last post also check for any electrical interlocks , which cause grounding (spark plug) or fuel supply (solenoid) shut off .

Note: I have seen numerous supposedly (New) carbs (floats and inlet needle valves) and even pumps (diaphrams) that were defective right out of the box. So don't assume all is fine with a simple replacement of component , but rather troubleshoot the symptoms 1st. There is something being overlooked ? Fuel Valve Open ? lol :)

Does carb feature an electric fuel solenoid?
If so, did a new one come with the new carb?
Or did you have to transfer the old one to the new carb?

Thanks ewalk

I actually pulled out the fuel tank and cleaned it. The plug is dry, no fuel getting to it. I removed the tank and cleaned it. Blew out the line inside the tank. Installed a new fuel filter. I also removed the fuel line and a little stream of fuel does come out when the ignition is turned on.

When I ordered the carb the gentleman behind the desk said the carb for the F525 comes without any needed adjustments. Apparently this info may not be correct?

As far as electrical interlocks. I've looked all over and can't find anything that stands out as a problem.

LOL, yes the fuel supply valve is on. :p

I did wonder if it was possible the new carb could be defective. I have fuel coming to the carb supply line, and the engine fires up when I spray starter fluid into the carb. So, I think fuel is not getting from the carb bowl, and up the main jet to the barrel of the carb???

I really appreciate the suggestions!

OK, you have fuel arriving at the carburetor inlet fitting.
Have you removed the BOWL to see if fuel might be getting into the bowl?
And you might answer my other concern about the presence or absence of a fuel solenoid on the carburetor (or not).
If there is a carb solenoid, and it is not working, your symptoms will be what you are experiencing.
Dialogue?

Hi mownie,

I did answer your questions earlier. I guess I did not hit the submit button after the preview message page.

Fuel is getting into the bowl. The carb did come with a new fuel solenoid and I can hear it clicking when the key is turned on and off.

This thing has me absolutely baffled.

Thanks...

Hi mownie,

I did answer your questions earlier. I guess I did not hit the submit button after the preview message page.

Fuel is getting into the bowl. The carb did come with a new fuel solenoid and I can hear it clicking when the key is turned on and off.

This thing has me absolutely baffled.

Thanks...

OK, if fuel is for sure getting into the bowl, and the engine wants to run when you spray a shot of carb cleaner (no ether) into the carb throat, the main jet must be blocked.
If you still have the old carb, try the old fuel solenoid in the new carb. Remove the plunger (and leave it out) from the old fuel solenoid before you install the solenoid into carb.
This will determine whether the new fuel solenoid is blocking the jet.
The fuel solenoid is only to help minimize the occurrence of an afterfire bang when shutting down a warm engine, so you might get a bang out of the muffler with the disabled solenoid.

Thanks mownie. I'll try switching the solenoid out tomorrow evening after work and report back.

A few things come to mind. Fresh fuel added is hopefully gas and not diesel. Also, is it possible that the throttle link is not installed as it should? You mentioned that there is fuel in the bowl. It still may be a good idea to at least confirm that you get a stream of fuel out when you check the solenoid. It wouldn't be the first carb that came out of the box witha sticking float valve. If all seems good there, and you've got compression- I would install a new igniter. The igniter can still release the spark but not release the spark at the proper time.

Adam: I will leave the mystery solution in the capable hands of both Mownie and Tom who have yrs of Mower small engine mechanical repair . Good luck Dude :). Let us know your experience...E !

Switched the solenoid out and the engine still won't fire. I did have a steady stream of fuel when I removed the solenoid.

How do I confirm the float valve is operating correctly?

I don't have a way to check compression, but with the plug removed there is a significant amount of air releasing when the key is turned.

I've been eyeing the igniter and was reluctant to replace it since the spark plug tester showed it was firing. If the float valve checks good I'll definitely replace it, as I don't see anything else it could be.

Really appreciate the help all!

To confirm the float needle valve is working, remove the fuel hose (safest and least messy) from the carb fuel inlet fitting. Remove the float bowl. Slip a spare piece of fuel hose about a foot or so in length onto the carb fuel inlet fitting.
Place the free end of hose in your mouth and blow your breath through the hose. With the float hanging down, you should be able to tell you are blowing through an open passage (and hear the air escaping at the needle & seat.
Now, take the tip of a finger and lift the float gently while you are blowing. As the needle valve covers the seat it should become impossible for you to blow anything through the hose.
After all this, I have to ask: Is the choke connected and closing properly?
An engine may fire up and run a couple seconds on a shot of spray carb cleaner even if the choke is wide open because the manually delivered carb cleaner is actually a very rich mix, and that is what it takes to get a stone cold engine running, and that is what the choke does.........cuts off the air so the inducted mix is very rich in fuel.

The fact that you ARE able to get a second or two of run time when you prime the carb manually pretty much says that compression and ignition are present and just like they should be.

The only avenue left to explore is the choke system.

Try placing a "gloved hand" (in case it backfires through the carb) over the carb throat while you crank the engine to see if that will provoke some improvement in starting.

I had the same problem with a honda engine. Ran out of gas, and wasn't tried for several weeks. Had the carb off, cleaned with cleaner, check plug,and blew out hoses, still no go. Finally keep spraying cleaner into carb(about 10 sprays) to keep engine running, and it finally cleaned itself up, go figure. Must have been some jet(??) blocked that finally cleared up. Don't know if this will help. Good luck.

Bob

Thanks for the tips. I'll give them a shot in the next couple of days.

Happy Thanksgiving!

Mownie,

I did the blow test you mentioned. Air is getting through fine, but as I lift the float, air is restricted, but does not completely shut off. Do you think this is a problem?

As far as the choke goes; I think its working correctly.

I did try covering the throat of the carb, but it still would not start.

Thx,

Adam

We know this much:
Fuel is entering the bowl.
The float and needle/seat are working. The fact that the blow test did not completely stop all the air would be a factor in a gravity fed fuel system, but for other reasons.......it would NOT be a cause for a cold engine not to start up and run.
In a post above you say you "Switched the solenoid out and the engine still won't fire."
Did you simply swap the solenoid "intact"?
Or did you follow my detail of instruction to "Remove the plunger (and leave it out) from the old fuel solenoid before you install the solenoid into carb."?
It would of course be a long shot for both the old and new carbs to have a defective fuel solenoid, but the trouble began after a fuel-out with the old carb and solenoid on the engine. Removing the plunger will render the solenoid inoperative and incapable of blocking the main jet.
If the engine still will not run even with the plunger removed, I would have to suspect a blocked main jet.

When you say " the engine fires up when I spray starter fluid into the carb", do you mean that you could indefinately run the engine on starting fluid if you tried -like it is actually running or you are getting a backfire?

Mownie - I had previously clipped off the plunger from the old fuel solenoid, as someone from the John Deere dealer recommended. Do you think I should try with it removed as well?

As far as the main jet goes; I have sprayed air through it and it appears to be unrestricted.

Tomplum - The engine will run as long as starter fluid is entering the carb.

Perhaps I should call someone for an exorcism? :(

Thanks gents,

Adam

If you snipped off the plunger that should have disabled it from obstructing fuel flow into the main jet.
This is beginning to sound as if the ORIGINAL cause of the engine quitting might have been something other than a simple "fuel out".
It might be the time to perform a "cylinder leak down test" with compressed air to see if all is well with the cylinder, piston, head gasket and such.

I know it's hard to judge, but does the engine sound really eager to run when you spray a burst of carb cleaner into the carb, or does it just barely run?

The engine sounds like its really eager to run when I spray the starting fluid in it. It fires up, just as it does when its running properly.

Is it possible either the throttle shaft or choke shaft plate was assembled wrong and either of these shafts aren't working properly? It's worth a look. Otherwise, it sounds as if either fuel isn't getting though the carb or the fuel isn't gasoline to me.

Success at last! It's been a few days since I've had a chance to look at the mower. I decided to clean the new carb one more time. So I cleaned it, installed it, did the ole, god please let her start routine, and BAM, she fired right up. Man it was music to my ears. My mother was so excited you would have thought it was a new car.

She loves to cut grass; matter of fact, she's out cutting leaves at the moment.

I really appreciate the help! You guys kept me motivated to keep at it and it paid off. Everyone's invited to my house for Christmas dinner. :)

Adam

Adam: Been a while since my original post of Nov 21st . As I said the KISS solution of really don't believe a Carb is clean until you have given it a thoroughly circuit cleaning . You have learned a lot in a week . Never hurts to learn all aspects of the Potential Problem . Thanx for letting us all know how it finally played out Dude ! :)

Hi Guys,
Thanks for posting such detailed carby problem solving instructions re the F525! I may as well post here since it is related...

I'm in Australia and I'm about to troubleshoot my own problems which developed since a bad tank of fuel. I'm fairly sure it's fuel related, since the F525 mower and my son's little 125cc Thumster bike both developed on ongoing stalling issues from the same day we refilled them both.

In my case, we puchased 91 Ron unleaded fuel with 10% ethanol, by mistake. Normally I just buy unleaded 91 or 95 octane rating.

Both machines still start and run a low throttle, but lacked power and eventually seemed to run out of fuel and stall. For the F525, if the grass was short and the blades not heavily loaded, it would run at quite low revs ok. But then all of a sudden it would start to hunt up and down in revs, and seemingly runs out of fuel and stalls. But it will restart after a short wait and idle ok. When it goes to stall, if I quickly stop the blades, and hit full-throttle/choke and then pull it back to idle, I've learned to stop it stalling. Then, after waiting about 10 or 20 secs, I could restart the blades at lowish revs, and slowly press on. But it's getting worse, and this happens about every 30 seconds or so now, so it's stop and start mowing for aver 2 hours on my 1 acre.

If it isnt actually a dirty fuel problem then I'm suspecting maybe the ethanol is no good for the J525 as I changed the fuel filter but it looked quite clean?

We fixed the bike carby. Dirty and no oil on the filter wasnt helping either! It came off the bike easily and yes, it had blocked jets, and we needed fine wire to clean them. A fine strand of old throttle wire did the trick, and it runs fine now. It was quite hard to push the junk out! of the jets.

Now to the mower. Just the mower carb doesnt come off so easily so I need to get the courage to work out how. Firstly Ive checked the fuel tap is on (lol) and fuel does run to the carby. So maybe then it's just gummed up the jets or ports also. So, will print off this thread and off to the shed I go...

Thanks again for the info provided here, and I will let you know how I go!

Cheers,
Bruce

If removal of the carb looks challenging, think how daunting putting everything back might be later.
For that I suggest you shoot lots of pictures prior to removing any parts, shoot from ALL angles as you may not recall "just how this connected/was positioned" later on.
As you remove parts, shoot additional pictures each time something comes off.
By marking your trail in photos, you will have created a "step by step" for reassembly later.

Hi Mownie,

Thanks for your suggestions, yes its a great idea to take photos. It helps stop that little problem of what to do with leftover parts at the end too!

I removed the air filter, filter support housing and cleaned them, as they were quite dirty. The prefilter was washed in fuel and recoated with the sticky spray.

Removed the fuel bowl and stop solenoid, and tested the voltage. 12.5V was present, so no problem there. I then decided to inspect the solenoid itself and, to my surprise, it did not retract the little metal needle when power was applied (using the chassis as earth). But if I touched it with the tip of my finger, it would 'snap in'. So I thought could this be it... so to get rid of it, I put the solenoid needle/tip in the vice, and trimmed it off gently with a hacksaw, to see if this would get the fuel through temporarily, until I can buy a replacement,

Then I reassembled, started and mowed for a few mins, and the stop problem seemed to have gone away - well, almost!
The problem re-arose. I decided to remove the solenoid again, and this time used a grinder to gently remove the pin all together, as I only took about 3mm or 1/8" off initially.

Reassembled, and away it went, better again than before I think, but after about 2-3 mins, the miss and cough started again. Dropping the revs and waiting the 5-10 secsat idle, and we could mow again. Im not sure if this is coincidental, but sharp zero turns seem to induce it, and to me I feel it seems like some fuel starvation as it hunts a bit as it starts to die.

But it is now definitely a lot better than it was. We mowed our 1 acre, and also our neighbor's as they are on holidays. But it was still painful and not like it should be. I cant imagine a New Solenoid is going to improve it further?

Do you think I should tear it down and thoroughly clean the rest of the carby from here?

I found the JD website quite good, and managed to print off some good pics of the Carby parts explosion. Just need to buy some new gaskets and the solenoid first, some time this week.

By the way, can I ask about another issue, the starter is also playing up a bit! Presently, we need to hold the start key in the "on" + "starter motor position", and lightly tap the bolt on the top of the starter with a hammer to get the solenoid to activate.

Seems to work every time, but I think I need to attend to the starter or the solenoid - what do you think? Is it easy to do and can it be disassembled? Tapping the solenoid body doesnt seem to help, but a solid/gentle tap on the bolt head which is holding the starter, on the solenoid side - does.

Your advice on these two issues is certainly greatly appreciated!

Cheers,
Bruce

On the fuel stop solenoid being hesitant to snap right in when 12V was applied......what you observed is actually "normal" in most cases. Reason being that when the metal plunger valve is extended while in place in the carb, it does not protrude from the solenoid as much as it does when out of the carb. While in the carb the plunger is seated firmly against its seat and is within "easy reach" of the electromagnetic field of the solenoid coil. Sometimes it is necessary to give a little push to the tip of the plunger toward the solenoid before it will snap in.
Even though a solenoid seems to be functioning correctly (plunger moving in) it is still possible that the plunger might not be retracting fully due to fuel varnish and unavoidable sediments finding their way into the plunger valve bore in the solenoid body. These foreign matters can become quite solid, limiting the amount of movement of the solenoid or seizing it fast in the bore. Of course since you have removed the end of the plunger entirely, this is no longer a possible issue in your case.
I do suggest a complete teardown and cleaning of the carb.
It would probably be wise to remove the fuel tank to clean it out thoroughly as well, especially if this machine has 500> hours on the clock.

Now to the starter/solenoid issue.
First thing you must realise is these starters have permanent magnet fields and therefore should not be struck sharply with any metallic objects to jostle them to life. Doing so can fracture the field magnets, rendering them useless and ineffectual.
Second thing here is to be absolutely certain that the battery is good, meaning that it has a standing voltage of near 13.2 volts before you attempt to engage the starter.
If you find the battery is not up to that par, place a battery charger on the battery and bring the voltage up.
Try engaging the starter while the voltage is 13.2 or higher (leave charger going if need be). If the starter solenoid activates now, you need to check that the charging system is working as it should.
If the battery checks OK, I suggest you unfasten and clean each and every connecting point in the battery cables between the battery and engine. Do this to the negative cables as well, they are equally important but often not considered when chasing gremlins.
If.......the starter solenoid is still recalcitrant after all that, the wiring that serves to engage the starter solenoid is likely suffering from some degree of "fatigue" (not uncommon considering the small wire size used by OEM to engage the solenoid).
Many machines exhibiting this symptom have been "cured" by adding a small Bosch relay to handle the solenoid engagement duties instead of the OEM key switch carrying that amp load. Adding the relay does not affect how the key switch controls the starter (meaning that the key switch and any inhibitor switches still rule the solenoid), it simply provides a separate solenoid load circuit to avail full battery voltage to "kick" the solenoid into engagement.
The "how to" on the Bosch relay can be posted later if needed.
Because this is an old thread and we may have additional discussion on your F525, you would do well to create a new thread of your own at this point.
If you choose to make a new thread, we can provide a link back to this one so details can be viewed easily if needed later.

Great news - all fixed!
The carby jets all looked clear, no sign of build up, all except for the main needle, the one which is regulated by the float controlling fuel into the float bowl.
I was about to reassemble the jets when I decided to use my mouth to blow through the fuel inlet, and discovered I couldnt. Manually moving the float up and down made no difference. I carefully removed the float pin, and discovered the needle was stuck in the seat. Once I freed it, it seemed to work properly. Then I sprayed a little carb cleaner in there, and then washed in some fuel, as I didnt want any rubber bits expanding from the cleaner.
Reassembled and tried restarting, but no luck!

To check for fuel presence I removed the stop solenoid and discovered the carby/fuel bowl didn't have any fuel getting through at all. Doh!

Turning my attention downstream...to the fuel lines etc. My new filter looked OK, the tank was full, and the fuel Tap on top of the tank had a clamp with a crimp, so it looked like it was a permanent mounting. I removed the fuel line off the Tap and discovered the Tap itself unscrewed easily, so I could check the internal screen filter if it had one. It didnt, so perhaps it might be the Tap. Blowing through it with the valve open, to my surprise I found it was really restricted. Having a dip or draw-tube into the tank, would mean it needed to be clear to be able to suck the fuel up and through to the fuel pump.

Again I sprayed some carby cleaner into both sides of the open tap, open and closed it several times in quick succession and and blew through it a few times (and got burned lips!) and suddenly the blockage, likely somewhere in the tap cleared!

Reassembled, and thankfully it started after about 15 -20 seconds or so, once the new fuel got through to the carby.

So thank you esp Mownie for your comments here, and those earlier in the tread which gave me the knowledge and confidence to attack a simple but frustrating problem.

The mower is now running better than ever, and maintains full power when needed without missing a beat. And now there's also that great degree of satisfaction in not having let a mere piece of mowing equipment beat you!

Wow, excellent thread here.

I have something a bit different but in this same ball park. And I'll say off the bat that I am mechanical inclined but not truely motor savy (i.e., i do brake jobs but am not a real seasoned trouble shooter).

The other day after finishing mowing my F525 quit running from full throttle. I tried playing which the seat saftey switch and just pretty much looked to see if anything else was obviously wrong...but would not start back up. I noticed the fuel filter did not appear full and some small specs of debris in the filter. I removed and tapped the filter but replaced and it seemed like it may have filled up more (fuel switch was on). Eventually, without any real change, it fired up. As i was done mowing I put it away and chocked it up to flooding (thinking maybe i had the choke on as its connected to the throttle).

today while mid-cutting and after starting and running fine for 25 min or more, it cut out. No real struggling or anything. just quit. tried restarting, checked obvious connections with nothing. I stuck a screw driver into the plug wire and put it near the chasis trying to see a spark and only the smallest spark could be seen (admittedly not a great piece of chasis available but even the battery terminal did not produce a jumping spark).

Unfortunately I ran out of sun to shore up my spark test but ill start there tomorrow. Fuel filter is ordered and ill prolly check out the immediate lines before moving to the carb (but the way it zonked out makes me this its electrical).

This mower has run extremely strong until now. It is cranking fine, and I can hear/feel compression. Im not sure what the best/easiest way to check for fuel is but this might be my next stop after simply spark plug/electrical. Any thoughts would be appreciated.

I suggest you clean out the vent in the fuel tank cap.
Probe the hole from both the outside of the cap and the inside (if the inside hole is visible).
A plugged/clogged vent in the cap prevents fuel from being drawn out of the tank after it runs a while.
I agree that a plugged cap vent usually causes some stuttering and loss of RPM before the engine finally dies but I would be sure to clean out the vent to eliminate that as a possibility.

"... but even the battery terminal did not produce a jumping spark..."

Very dangerous thing to do is making a spark near the battery.
Hydrogen gas!

Alright, some more info. I had a chance to do a bit more today. First of all, battery was completely dead today (never happened before). So most of what i did was with a jump box attached. I started checking all electrical leads and I found the negative battery cable with a short which might explain the battery being dead (but i dont think its the bigger issue). I will replace the cable but have taped it up for now.

The weird part was that it started right up with a jump and was running strong with no issue. I wanted to get it to the garage as its in the yard so I tried to move it and having disconnected the seat saftey, it tried to shutdown so I put the brake on (to prevent self-shutdown) and went to reconnect the saftey. Before i could connect it, it went from full bore sounding great to off...(saftey seemed to be working fine as i could hear it click on when depressed).

So i started checking stuff. The gas tank has a vent spout which is clear and I probed the vent hole as much as possible. It looks like there is plenty of fuel getting to the filter now and after emptying the filter and restarting (trying) it looks as though fuel is being pulled from the filter (at least some suction).

I did verify spark is coming through the wire, I may not have been getting full saftey switch depression yesterday. Plug itself looked fine, not wet.

At least two more times, i tried it randomly and it started up fine ran for some time, then quit. I noticed while trying to crank it that when it did crank it was strong. But sometimes it would refuse to crank which I attributed to battery but im not so sure as the jump box is pretty powerful and i adjusted the connections a few times. It seemed like as I continued to try starting, it would refuse to turn over more often than not.

Not really sure where to start but I thought I might remove the ignition/control panel and check to make sure it looks good. The quirkiness is making me think electrical and the intermitent starts make me think fuel/compression is not an issue. I may try starter fluid to be sure fuel is present in the fire box. I have the battery on a charge but will have the jump box if needed anyway.

Thoughts? btw fair enough on the H2 gas but no explosions so far...

yah, yer dodging the bullet on the battery hydrogen gas so far, but when you start using starter fluid on that small air cooled engine will soon be time for a new engine....

A few things:" negative battery cable with a short" Nope. Maybe you could elaborate a bit more. First off, you really need to verify the seat switch is good and put that to bed. The battery needs to be charged. There is a solenoid below the carb that needs to be fed power to allow fuel to enter the combustion chamber. I've seen the igniter (which releases the spark at the proper time) become damaged from excessive amperage jump boxes. It must back feed as the igniter is not on a power circuit. A failing igniter will cause that stall hot issue that you were having. Use carburetor spray rather than starting fluid to be kinder to your engine. rcbe X2 on that one!

Carb spray noted.

The negative battery cable had a place in the line where it looks like heat deteriorated the jacket and exposed the wire. The wire was not looking terrible so I think it happened relatively recently.

I'll look myself tonight but is the carb solenoid separate from the igniter? Anyway to check these without replacement? Battery should be good by tonight.

No luck starting today. Battery read fully charged by my charger but when I connected it and tried to start I saw a small spark from the positive terminal and the ignition went dead (had to turn off the key to retry). Second time with same result and the h2 gas warnings kept me from any more. Im thinking of trying a new battery but the jump box didn't start it so I'm not sure this would do it unless just so dead there was a problem.

I removed and checked everything I could from gas tank. I removed the solenoid (pin looking thing at bottom of carb bowl) and there's definitely fuel. Spark still coming through my grounded screw driver. Connections at control panel looked fine. Brake switch looked fine (hard to see). I can here a relay clicking on when power is connected and key is switched to run.

I'll need to research the igniter and can't say anything about that right now. Any thoughts?

HAve you cleaned the battery terminals? The negative cable can rub against the frame all day long as it's purpose is to provide a ground. Clean the battery terminals, replace the cables or ends if in question and ensure good grounds. If the battery itself is questionable- replace it. A good carb solenoid will click as the key is turned to on. It's purpose is to prevent fuel from going up the tube in the center of the carb- to lessen backfire. Fuel would still enter the bowl w/ a bad solenoid. Let's start with this.

Terminals look clean. I brushed them down to be sure but its cranking fine and lights are strong.

After a rain delay, the carb solenoid sounds like its engaging fine. From the stuff I've read I imagine you'll point me to the ignitor next. Is there any way to check the ignitor without replacement? Since I have to order the parts online it would take several days to receive stuff if replacement is the only real test method.

Thanks for the help so far everyone. I'm hopeful this can be solved.

In the Deere manual it basically says the following: The coil test is to measure resistance between the wiring lead terminal and coil terminal should be between .48 and .72 OHMS The measure between the spark plug cap terminal and coil terminal. 10.9- 16.3 OHMS. The manual says to replace the coil if not in these specs. From there, this manual says to be certain that the terminals are clean and components are grounded and it still won't start to replace the igniter.
Another igniter test I have says to check between the case and the terminal of the igniter. + on the case and neg on the terminal should show .2- .7 and reversed should be 1-5 OHMs Me, I just put on a known good one I have in my tool box...

Ignitor changed and it fired right up. Thanks for the help.

Nice.