Summit Treestands
Small Engine Repair
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Contributors to this thread:
Thunderflight 13-Jun-18
Woods Walker 13-Jun-18
bb 13-Jun-18
AccMan 13-Jun-18
Thunderflight 13-Jun-18
Shuteye 13-Jun-18
zeke 14-Jun-18
Joey Ward 14-Jun-18
Bogie 14-Jun-18
Norseman 14-Jun-18
Thunderflight 14-Jun-18
longbeard 14-Jun-18
Brotsky 14-Jun-18
TD 14-Jun-18
bb 14-Jun-18
longbeard 14-Jun-18
Grey Ghost 14-Jun-18
Thunderflight 15-Jun-18
Thunderflight 15-Jun-18
AccMan 15-Jun-18
Grey Ghost 15-Jun-18
Joey Ward 15-Jun-18
bb 15-Jun-18
Thunderflight 15-Jun-18
itshot 15-Jun-18
Grey Ghost 15-Jun-18
Bowfreak 15-Jun-18
Joey Ward 15-Jun-18
AccMan 15-Jun-18
itshot 15-Jun-18
AccMan 15-Jun-18
AccMan 15-Jun-18
TD 15-Jun-18
Thunderflight 15-Jun-18
JL 15-Jun-18
TD 16-Jun-18
AccMan 16-Jun-18
Thunderflight 17-Jun-18
JL 17-Jun-18
Thunderflight 17-Jun-18
JL 17-Jun-18
Thunderflight 18-Jun-18
Joey Ward 18-Jun-18
bb 18-Jun-18
JL 18-Jun-18
Thunderflight 18-Jun-18
TD 19-Jun-18
JL 19-Jun-18
Dirk Diggler 19-Jun-18
Thunderflight 19-Jun-18
Thunderflight 19-Jun-18
OkieJ 20-Jun-18
Pat Lefemine 20-Jun-18
Salagi 20-Jun-18
Thunderflight 20-Jun-18
Thunderflight 20-Jun-18
JL 20-Jun-18
Thunderflight 21-Jun-18
Thunderflight 24-Jun-18
Grey Ghost 24-Jun-18
Thunderflight 24-Jun-18
Grey Ghost 24-Jun-18
Solo 24-Jun-18
bb 24-Jun-18
Grey Ghost 24-Jun-18
Thunderflight 24-Jun-18
Thunderflight 24-Jun-18
Grey Ghost 24-Jun-18
Thunderflight 24-Jun-18
scentman 24-Jun-18
Coyote 65 24-Jun-18
Thunderflight 24-Jun-18
Norseman 24-Jun-18
Grey Ghost 24-Jun-18
Thunderflight 24-Jun-18
JL 24-Jun-18
Thunderflight 24-Jun-18
bb 24-Jun-18
JL 24-Jun-18
Solo 24-Jun-18
Grey Ghost 24-Jun-18
JL 24-Jun-18
Solo 24-Jun-18
TD 24-Jun-18
Solo 25-Jun-18
Thunderflight 25-Jun-18
Thunderflight 25-Jun-18
Grey Ghost 25-Jun-18
Thunderflight 25-Jun-18
TD 25-Jun-18
Thunderflight 25-Jun-18
JL 25-Jun-18
Grey Ghost 26-Jun-18
Thunderflight 26-Jun-18
Grey Ghost 26-Jun-18
bb 26-Jun-18
Grey Ghost 26-Jun-18
bb 26-Jun-18
Solo 26-Jun-18
Thunderflight 26-Jun-18
JL 27-Jun-18
Thunderflight 28-Jun-18
TD 28-Jun-18
Grey Ghost 28-Jun-18
bb 28-Jun-18
JL 28-Jun-18
Solo 28-Jun-18
TD 28-Jun-18
Solo 28-Jun-18
JL 28-Jun-18
Thunderflight 28-Jun-18
JL 29-Jun-18
Thunderflight 29-Jun-18
Thunderflight 09-Jul-18
Solo 09-Jul-18
bb 09-Jul-18
JL 09-Jul-18
Thunderflight 09-Jul-18
nowheels 10-Jul-18
Thunderflight 10-Jul-18
13-Jun-18
This is kinda hunting related because without my riding tractor I can't get my food plot in.

Sunday I'm mowing in areas no sane person would take a riding tractor when I hit a rock. I didn't hit it hard and I shut off the mower deck before I backed off. The rock was small and I barely nicked it. When I turned off the deck the whole mower shut down and won't start. It'll crank like a champ, but will not kick over.

So far this is what I have done and the darn thing still wont start:

-Pulled the fly wheel and the shear pin looks as new as the one I just bought at the John Deere store.

-Both spark plugs are sparking

-I have compression, but I haven't put a gauge on it to see how much.

-Replaced the fuel pump

-You can hear the fuel shut off thingy tick in the carburetor when you turn the ignition to the first notch.

-I put a few drops of gas in the air intake and the first cylinder fired, but didn't start the engine.

-The 25 amp fuze is fine

The only thing I have not done is replace the relay which I will probably do tomorrow.

I'm not an engine expert, but it seems to me I have covered all the bases. I'm thinking that since it died when the deck switch was shut off that I probably have a short or bad switch somewhere. I probably should down load the wiring schematics and start testing wires with a multi meter.

Oh, my riding tractor is an old Scotts L2048 (same thing as a John Deere L120) with a Briggs and Stratton 20 hp OHV motor.

Thanks for any advise.....

From: Woods Walker
13-Jun-18
Some mowers have built in safety switches on them that won't let the engine start if you're not sitting in the seat, the brake isn't off, etc. When you hit the rock you may have damaged one of these.

Also.....some mowers won't start if the oil's low. Just some guesses. Let us know what you find.

From: bb
13-Jun-18
If you pour fuel in the carb and it fires, it's likely you aren?t getting gas did you change the fuel filters? Could be a sensor. worth checking that out. I know guys that will pull the fuel line off and crank the engine to see if it pumps fuel. but I would never suggest you do that.

From: AccMan
13-Jun-18
If you can pour gas through the carb and it will fire then you are not getting gas. When you hit the rock did it jar the gas shutoff closed? Stranger things have happened. Or maybe the needle in the carb is stuck.

13-Jun-18
AccMan, you might be right. I probably need to clean the carb out. Maybe something is sticking.

From: Shuteye
13-Jun-18
I would try a shot of starter fluid in the carb before pouring gasoline in there. If you have the plugs firing it will start at least for a few seconds. If it starts and stops it isn't getting fuel. If it doesn't fire you have an electrical problem. Once you isolate which problem it is you can go from there.

From: zeke
14-Jun-18
Some engines have a safety solenoid on the carb that shuts the gas off if the you don't set on the seat, engage the brake, disengage the deck etc. If i remember correctly it is controlled by a wire that clips to the bowl or near there.

From: Joey Ward
14-Jun-18
Verify you have plenty of gas in the tank. Could be out of fuel. :-)

From: Bogie
14-Jun-18
Put Star-tron fuel additive in your gas. run seafoam in your gas to clean out the build up of gas-varnish

From: Norseman
14-Jun-18
Check your choke and throttle cables. They may of popped off the carb. Also change out your fuel filter and check fuel pump. Good luck

14-Jun-18
I'm pretty sure it has to be electrical. One thing I forgot to add was that I went to pull the plug on the relay to check the connections for corrosion. When I tugged on it the whole relay came out. Our local John Deere store has one and it isn't expensive. Hopefully this will fix it. If not, hey, at least I've got a new relay and fuel pump installed..... LOL

From: longbeard
14-Jun-18
This is an interesting and refreshing change from what is usually written here. I really can’t add anything that wasn’t already mentioned. My interest is piqued please let us know what you figured it out to be

From: Brotsky
14-Jun-18
I love figuring this stuff out. Please do come back and let us know what ends up being the culprit. Lots of good advice already given!

From: TD
14-Jun-18
I'm betting no spark, likely some kind of safety interlock switch. Easy to check spark, especially if you have a little brother..... Most auto stores will have a spark tester to check it, they are pretty cheap and handy. Or if you have two people one can pull the plug wire, plug a screwdriver in it and hold the shank about 1/4" off some grounded part of the engine. Make sure you/they are holding the plastic handle! Will need someone on the seat cranking it over, in neutral, blade/deck disengaged, maybe pushing a clutch, etc. so interlocks are engaged.

If no spark, quick and easy is to cycle through all the deck/blade engagement controls to make sure they are fully disengaged or the deck lifted. Seat switch is fully engaged, etc. Trans sometimes has to be in neutral, etc. (many have a reverse kill if deck is down and engaged and you back up)

Still no spark? These engines are grounded out to stop them, not like automotive and shut off power to the system. There will be a "kill" wire running to the engine. Disconnect it and try to start. My guess is it will fire up, if it does you will have to reconnect to shut it off. Then it's a matter of finding out which switch or wire is the issue. Don't overlook oil level switches, etc. especially if the equipment is on a slope.

Let us know what you finally wind up with!

From: bb
14-Jun-18
Problem with that theory is he confirmed he was getting spark, even dumped gas in the carb and got it to fire. My bet is the relay he unplugged drives the fuel pump and is preventing the pump from sending fuel.

From: longbeard
14-Jun-18
I’m heading to NJ now to place a bet on what bb described!!

From: Grey Ghost
14-Jun-18
I agree with bb, as well. He's getting spark since the engine fired briefly when he dumped fuel in the carb.

Assuming it's a mechanical fuel pump, I'd disconnect the fuel line at the carb and stick the end of the line in a jar, then crank it over a few times. There should be healthy squirts of fuel. That will confirm fuel delivery. I've had brand new mechanical pumps that didn't work right out of the box.

If the pump checks out, that leaves air. Have you replaced the air filter lately? I've never had a dirty filter prevent an engine from starting, but stranger things have happened.

Beyond that, I'd start looking into any automatic shutoff features that are on the engine. My tractor's engine will shut down in neutral If I don't set the brake before standing from the seat, or if I try to stand with the tractor in gear. One time, the wire to the switch under the seat came loose, and the engine wouldn't start. Took me a while to hunt down that one.

Good luck,

Matt

15-Jun-18
UGH!!!!

Spark: Yes Compression: Yes New fuel pump: Yes (works off vacuum) New Relay: Yes Fuse: Good Fly wheel sheer pin: Good gas in carb air intake, did it fire: Yes

OK, so It's obvious I'm not getting fuel. I'm guessing my fuel shut off valve isn't working even though I can hear it click when I turn the ignition key. This sucker isn't cheap. I'll be shooting wires before I buy it.

15-Jun-18
UGH!!!!

Spark: Yes Compression: Yes New fuel pump: Yes (works off vacuum) New Relay: Yes Fuse: Good Fly wheel sheer pin: Good gas in carb air intake, did it fire: Yes

OK, so It's obvious I'm not getting fuel. I'm guessing my fuel shut off valve isn't working even though I can hear it click when I turn the ignition key. This sucker isn't cheap. I'll be shooting wires before I buy it.

From: AccMan
15-Jun-18
If you disconnect the fuel line from the carb and cut on the ignition switch I would think you should have a stream of fuel running out, and if not the switch is not mechanically opening even though you hear the click. Can't you bypass the fuel shutoff with a longer piece of hose?

From: Grey Ghost
15-Jun-18
IIRC, on some engines you can simply remove that shut-off solenoid and plug the hole. It's not absolutely necessary to run the engine with one.

Matt

From: Joey Ward
15-Jun-18
I sure hope you've check the fuel tank.

No need to ask me how I know. ;-)

From: bb
15-Jun-18
Change the fuel filters, inexpensive to rule that out as an issue

15-Jun-18
Joey, LOL I actually did that, but not until I had worked on it for a few hours.

BB, no issues with the filter. It flows great.

From: itshot
15-Jun-18
if you get fuel and still nothing, spark timing was whacked when you whacked rock, just a guess but have seen it happen

From: Grey Ghost
15-Jun-18
Perhaps this will help.

Matt

From: Bowfreak
15-Jun-18
zeke has the answer. The solenoid shuts off the flow of fuel when the key is off. It keeps the engine from backfiring. It should screw right into the bowl of the carb. They are easy to test. I had one fail on a Murry/MTD mower I had a few years ago.

Also...there is a chance you can take it out and clean it up and make it work again. I did that to mine for a while and it worked until the wire sheared off.

From: Joey Ward
15-Jun-18
Ok then. :-)

Here's a link to the owners manual, if you don't have one. May be of some help.

https://www.deere.com/common/docs/stellar/answer-center/Scotts-S2048-S2554.pdf

Itshot suggests a timing issue. I think the valves got out of adjustment on the hit.

You might want to look at youtube to find a good tutorial on adjusting the valves on that B&S twin. May be of value.

Other than what you've already done, I'm out of ideas.

Good luck

From: AccMan
15-Jun-18
If you disconnect the fuel line from the carb and cut on the ignition switch I would think you should have a stream of fuel running out, and if not the switch is not mechanically opening even though you hear the click. Can't you bypass the fuel shutoff with a longer piece of hose?

From: itshot
15-Jun-18
good point joey, if overhead cam type, the cam gear or chain could slip or rocker could flop off valve stem... lots of things happen when things in rapid motion are suddenly forced to stop

hoping its just fuel supply issue though

From: AccMan
15-Jun-18
This thread has made me go look at my mower. I have the first rider in years with the new big yard. Holy crap, it has a fuel pump and electric shutoff valve on the carb. What happened to simplicity? I bet the shutoff valve is because of ethanol gasoline ruining the viton tips on needle valves letting carbs flood and empty tanks in the garage while parked. I watched the posted video on the shut off valve and as dense as I am I just had to go research mine and was shocked at what I found.

From: AccMan
15-Jun-18
I have re-read the original post and it seems that the motor fires after pouring gas through the carb. I would bet on the solenoid gas cutoff valve in the carb. If you have a bad connection giving voltage drop the plunger probably wouldn't move far enough to allow gas flow. Run a jumper directly from the + side of the battery to the solenoid connection and see if it will start. If so, check voltage at the connector and see if you get full 12 volts to ground.

From: TD
15-Jun-18
Need fuel pump (normally vacuum pulse fuel pump) because it's common now to have the fuel tank as low or lower than the carb, no gravity flow. The fuel solenoid is so when you shut off the engine, especially at higher rpms, raw unburnt fuel does not keep getting pumped through the engine and into a red hot muffler where it explodes in a "backfire". Or in some cases a hot spot in the cylinder head will continue to ignite the fuel without an ignition spark and keep stumbling along running or "dieseling".

If you can hear/feel the fuel solenoid clicking it's likely working, not much to them but windings and a rod/needle and the valve seat hole is so big I've never seen one clogged. Have seen rubbish jam up the needle in the windings, but they won't move or "click"then.

Still need to check the spark to make sure it is steady and strong. If it were fuel if should start and run a few seconds with a shot of starting fluid (great diagnostic tool). Not just a random one time "pop" (which actually could be a timing issue like itshot and joey said. I've seen pushrods come off rockers on OHV engines. (Honda's, probably have 30 or 40 of em at the shop.... haven't worked on a Briggs engine in 10 or 12 years)

If good spark I'd take a look at the carb float bowl next, most will have some kind of a drain plug, some even a drain valve. Check for water. if you were Baja racing sometimes water that can accumulate at the bottom of the tank will slosh up into the pickup. Easy to check before diving into the carb. A big fan of checking things that are easy first. =D

15-Jun-18
When it rains it pours... my F150 tansmission just went out...

From: JL
15-Jun-18
A question to clean up the rabbit holes....

1. Looking at your OP....I need to clarify....AFTER you hit the rock and BEFORE you shut off the deck PTO...was the engine running normally?

If NO....the engine did not run normally right AFTER rock contact, then we need to ask a few more questions about the engine.

If YES....the engine ran normally BEFORE you moved the deck PTO (shut off the blades), we need to take a closer look at your deck PTO switch system.

If I read your OP correctly....the engine shut down after you physically moved the deck PTO to stop the blades...yes??....no?? If the engine ran normally immediately after the rock hit....it doesn't sound like you have an engine internal, fuel or spark problem. If the rock hit did create an issue with one of those 3 things....logic would tell us the engine would not have run normally after the rock hit regardless of any further action you took after the rock hit.

Might have to start another thread about your F150 tranny.

From: TD
16-Jun-18
F-150 trans........ Talk to Joey...... can't help ya there..... =D

From: AccMan
16-Jun-18

AccMan's Link
Trans rebuild

17-Jun-18
Well I give up. I'm taking it to a local guy who does small engine repair.

Last night I cleaned up the carburetor and did a function check on the fuel shut off solenoid (works just fine). This morning I put it all back together and still nothing.

There is something up with the fuel pump. I don't know if there isn't enough vacuum to get it to work or maybe I just have another bad fuel pump.

Either way I'm pretty much done screwing around with it.

My F150 is at the local Ford dealer. It started slipping, the Transmission Fault warning came on, the Over Drive light started flashing, and it's leaking fluid out of the rubber plug on the bottom of the bell. Sucks, but it's a 2005 with 170K on it. I hate to say it, but this kinda stuff is to be expected.

From: JL
17-Jun-18
T-Flt.....was it running normally before you disengaged the blades?

Sorry to hear about your tranny....better now than the day before the opener.

17-Jun-18
Yelp it was running great.

From: JL
17-Jun-18
"" Yelp it was running great. ""

Ok.....based on that confirmation.....me thinks if it was running great up to the point you pushed in the PTO switch....I see you're problem in one of the switches and NOT an engine problem.

I had a diagram last night of your lawn tractor's electrical system. Because it shut off only when you moved the PTO shut off, that would be a logical place to start.

It should have an electrical connection somewhere there as part of the engage/electrical safety system. Check the electrical connection and make sure it is properly connected, not loose or broken wires....something obvious. If nothing observed, remove it, check for corrosion, dirt, funk and spray it out with some WD-40 and reconnect. Try to start. It's possible the switch itself is bad. In that case you'll need to do some switch testing if you're comfortable with it.

Check your seat safety switch/wires the same way as above.

Check the brake/clutch/neutral switches/wires the same way as above.

Confirm oil sensor connection/wires as above. (and oil level)

Confirm ALL fuse links are good and not blown....use a meter.

Check the key switch and wires as above.

Hopefully it's one of those switches in the electrical safety system. If not, we can go from there.

18-Jun-18
Man, thanks I appreciate you taking the time to dig into this.

I never did check all the wires. I'll take a look at these tonight.

From: Joey Ward
18-Jun-18
Electrical is fine. If it was malfunctioning safety switch, the engine would not turn over. i.e., seat, brake, deck........ You can rule those out.

So now we're down to air or spark.

Only way timing can get off on those engines if the keyway on the shaft is broke. He verified it's fine.

Getting spark on both cyclinders? Verify that.

Air cleaner clean? Easy enough to look at. Remove and clean off.

Couple shots of starter fluid in the carb should fire her up. At least for a few seconds.

You could try cranking with the gas cap off. See what she does. Vapor lock somewhere?

Only other thing I can think of is when you hit the rock, pushrods may have crimped slightly throwing the valve positioning off.

Sorry about your truck. Alwys a good idea to periodically check trans fluid level, color, and smell. That milage on that year truck shoul;d not have much to do with engine or trans issues if maintained.

Can't help you out more on that end. Fixing trans problems is outta my wheelhouse.

From: bb
18-Jun-18
I know this has been mentioned several times but did you actually verify that you have fuel being pumped by the fuel pump? disconnect fuel hose and pump into a coffee can?

From: JL
18-Jun-18
My Craftsman will run if you get off the seat with the key in position #2. It will start if you depress the clutch and off the seat. If you get off the seat in key position #3 it will shut down. Point being it could still be a switch or wiring....at least on a Craftsman. That is why I leaned that way. It was running fine up to the point he turned off the PTO/blades. Based on that is why I'm suspect it is in the switch/safety system. If something in the valve train got bent or messed up on the impact....it should have been obvious while the engine was running. There should have been funny noises, tapping, maybe backfiring and even shutting down.

However.....not to get tunnel vision....I did some more looking online and quiet a few JD folks had the fuel tank vent cap clogged. He could unscrew the cap and try to start it. If it starts then clean out the small hole on the cap.

I had a spark plug a couple of years ago on a mower that looked like it was sparking good. I replaced the plug anyway and that solved the problem. He said one cylinder fired when gas was put in. New plugs would be worth a try. At the same time I'd check the compression with a gauge.

18-Jun-18
Ok all the switches are good.

Fuel is not coming out of the fuel pump.

I cant get it to start with starter fluid.

Pouring a few drops of gas down the air intake has occasionally worked.

Well, my tranny repair will cost me 2500 or so. Its ok, its better than the 4k the Ford dealer 2anted to charge me.....eek

From: TD
19-Jun-18
Not familiar with that engine..... but fuel pump is likely vacuum pulse. If it's not turning over (fairly fast too...) no fuel will pump.

Find a kid or spouse to hold the plug wire terminal when cranking..... (just kidding..... kinda.... my lil brother still brings this stuff up from like 45 years ago....) Cheap spark tester from the auto parts store. Great tools. Last a lifetime.

Not gonna help the tranny though..... sorry... (sigh... I remember when "tranny" had pretty much only one meaning.....)

From: JL
19-Jun-18
Did you unscrew the gas cap and try to start it?

From: Dirk Diggler
19-Jun-18
Coulda just been sold a bad fuel pump. Wouldn't be the first time.

19-Jun-18
JL, yelp I've already done that.

DD, I'm wondering the same thing.

19-Jun-18
JL, yelp I've already done that.

DD, I'm wondering the same thing.

From: OkieJ
20-Jun-18
I have a older John Deere mower also and I had a incident where I wasn't getting fuel from the fuel line and noticed fuel filter was dry. After trying several things i decided it had a plugged line from the tank, so I took cap off and used a compressor to blow into the tank with a rag over the fill spout and the problem was solved.

From: Pat Lefemine
20-Jun-18
I find myself strangely drawn to this thread. I need to know how this ends!

From: Salagi
20-Jun-18
Me too Pat.

20-Jun-18
Endorsed by Pat!

Awesome!

Still working at it.

20-Jun-18
Tranny: major leak coming from the torque converter. Itll be rebuilt and back in in next week.

I need to start a go fund me account to pay for it... LOL

From: JL
20-Jun-18
"" Ok all the switches are good. Fuel is not coming out of the fuel pump. I cant get it to start with starter fluid. Pouring a few drops of gas down the air intake has occasionally worked. ""

If you confirmed all the switches are good.....if it is a vacuum fuel pump.....do compression check on both cylinders with a gauge. It should be over 100 from the Youtubes I looked at. The one vid I looked at of a JD had low compression on one cylinder. He pulled off the valve cover and turned the engine over paying attention to the valves and push rods. In his case, the push rods were bent. One valve wasn't moving. This was his cause for the low compression which in turn would mean low vacuum which wouldn't drive the pump. Also try squirting starting fluid in both cylinders one at a time. Try to start it and see if it only tries to start on one cylinder. That would suggest the other cylinder/valve train could be the problem.

21-Jun-18
That is what I'm thinking too. I saw the same video. I'm off tomorrow. I'm going to mess with it a bit more before I take it to a shop.

24-Jun-18
UPDATE:

I bought a compression tester.... nothing, didnt move the needle. I stuck an arrow in each piston and they arent moving..... EEEEK

From: Grey Ghost
24-Jun-18
Now it's sounding more like a starter problem, if the engine isn't turning when you crank it.

The plot thickens.....

Matt

24-Jun-18
The starter is fine. It turns over like a champ. The lifters move a little but the pistons arent doing anything

From: Grey Ghost
24-Jun-18
The starter could be spinning, but not engaging with the flywheel.

I'm not familiar with your specific engine, but most starters have a bendix drive that engages and disengages the starter gear with the flywheel. It that bendix is malfunctioning or broke, the starter will spin but not engage.

Do you have a diagram of your engine that shows all the major components?

Matt

From: Solo
24-Jun-18
LOL, T-Flight. Getting 'go fund me' donations for a tranny operation should be pretty easy nowadays. Just get a print out of registered Democrats, and prey on them...

From: bb
24-Jun-18
At the very least a broken starter Bendix, Worse broken starter and bent crank

From: Grey Ghost
24-Jun-18
If the starter is engaging the flywheel, but not moving the pistons, a sheared crank shaft or broken piston rods is about all it could be. Both of which, would likely cause a horrible racket when cranking.

You can remove the starter and hot wire it to confirm the bendix is working. Youtube it, there should be several how-to examples.

Good luck, brother, and keep us posted

Matt

24-Jun-18
Fly wheel is turning just fine.

24-Jun-18
Looks like i can get a replacement motor on ebay for just over 600.

From: Grey Ghost
24-Jun-18
T-Flight,

I was checking out your engine here:

https://www.green-parts-direct.com/john-deere-parts-diagrams/john-deere-l120-lawn-tractor-with-48-in-mower-deck-material-collection-system-pc9290-crankshaft-piston-engine-gu20279-gu20453/AD-4275-175293-130448

You can scroll thru the smaller windows at the top of the page to get to diagrams of every part. It doesn't appear to be a very complicated engine to tear down and repair, and parts seem relatively cheap. That may not be your thing, though....

Sorry for your troubles. If I were nearby, I'd offer to come over and help.

Matt

24-Jun-18
I think the sound i heard before it shut off wasnt the blades hitting a rock.

From: scentman
24-Jun-18
This may be running a close second to the Rompola thread... hope you fix it, planting season close to over.

From: Coyote 65
24-Jun-18
According to the parts diagram that Grey Ghost posted, it may be as simple as a shaft key that has sheared.

Terry

24-Jun-18
I can easily push the pistons with the arrow. Also there is no grit or metal in the oil.

From: Norseman
24-Jun-18
Check the blinker fluid yet?

From: Grey Ghost
24-Jun-18
"According to the parts diagram that Grey Ghost posted, it may be as simple as a shaft key that has sheared."

Good call. That shaft key that holds the crank gear to the crank shaft may be sheared. It would certainly be worth checking before springing for a new engine.

If it were mine, it would already be in pieces all over my garage floor. I love tinkering with engines.

Matt

24-Jun-18
The only reason it isnt in a million pieces is because im busy with other stuff...lol

From: JL
24-Jun-18
Something is moving inside if he is getting lifter movement when it turns. Crank shear key could be a possibility. I'd be a little curious with the PTO engaged (motor off), turn the blades by hand and see if the pistons and lifters move. Did the flywheel also turn?

24-Jun-18
Man.... i hope its just the shear pin. I have a couple in my truck.

I should have the truck back this week.

From: bb
24-Jun-18
it's sure sounding like the connection between crank and flywheel

From: JL
24-Jun-18
Maybe try to lock/hold the engine from turning from the top (flywheel?) and if you can grab the crank pully from underneath try to turn it. I'm thinking it shouldn't turn or have any rotational slop if everything is in place and snug. That should hopefully let you know what is going on there.

From: Solo
24-Jun-18
I haven't read much of this thread, so I don't know if this was previously mentioned, but hopefully the timing gear hasn't jumped a tooth or two. Happened to my old John Deere mower years ago when I hit a rock. When I cranked it over, occasionally it would run for a moment or two, but it would backfire, which is pretty typical for a valve timing malfunction.

Don't know what your motor has, but mine had a fiber timing gear, which can be prone to jumping teeth.

From: Grey Ghost
24-Jun-18
Solo, a jumped timing gear wouldn't prevent the pistons from moving when the rotating assembly is cranking. It would cause valve timing problems, but the pistons would still cycle.

The bottom line is, if the flywheel is turning, but the pistons aren't moving, there's a disconnect from the flywheel to the crankshaft, or from the crankshaft to the pistons.

Thats really the only the two options, IMO.

Matt.

From: JL
24-Jun-18
^^ That's where I'm heading too.

From: Solo
24-Jun-18
OMG, that's a fact, GG. Like I said, I haven't kept up with this thread. Flywheels have a key that connect them to the crank. It's rare from my experiences, but the key can shear and cause that symptom. I hope it's something that simple. Thanks for waking me up, GG.... ;^)

From: TD
24-Jun-18
OK.... here is a scenario..... reading over, you checked the flywheel key earlier already? Pretty much to do that you removed the flywheel, inspected the key. Assuming you reassembled the key/flywheel correctly (the key didn't get pushed or fall out on assembly), that flywheel nut is hard to torque down properly. (Hate to admit it..... I don't torque them, I use an impact gun and get them "tight". It's hard to keep the engine from turning when using a torque wrench. There are ways, but none of them easy.... I've broken enough fins off flywheels to know.....)

If that flywheel nut wasn't tight enough the starter alone can shear the flywheel and with the tapered shaft and all it could (cross your fingers) just be spinning on the crankshaft. If not..... something pretty serious. Either broken crank or (very unlikely) both connecting rods cut loose at the same time. (if you checked both cylinders and both doing the same thing.)

If the crank or conn rods.... I'd look to a new engine unless this was a very low hour engine. Parts alone likely a third of the cost of an engine.

Good luck, I'm rooting for a loose flywheel.....

From: Solo
25-Jun-18
Dang, I just gazed upward and saw that the key was already mentioned. Sorry for wasting bandwidth...

I will add that if the rods or crank let go, then you can pretty well figure the valves are toast, with the added possibility of piston damage, too...

Now, if that was a two-stroke mote, I be hoggin' out the intake & transfer ports, and raise & polish the exhaust ports to the max and mill the heads to compensate, slap on some big carbs & a set of expansion chambers, and turn that rider into a fire breathing go cart. Cue in some Tim 'the Tool Man' Taylor grunts..... argh...argh....argh.....

25-Jun-18
Im gonna pull the motor tonight and open it up. As it turns out the bowfishing guide (dont have my own boat yet) is also a small engine mech. I. Gonna send him some pictures and also youtube the fix. Worse case i buy a new motor on ebay. They are just over 600 with shipping.

25-Jun-18
Question: assuming it fits, what is the plus of putting a bigger motor in it? Its a 20 hp now. How much more would i get with a 24?

From: Grey Ghost
25-Jun-18
" Its a 20 hp now. How much more would i get with a 24?"

About 4 hp. ;-)

Matt

25-Jun-18
Well the nail is in the coffin.

I just got off the phone with a local small engine mechanic. He said I most likely threw a rod and that it'll be cheaper to just replace the engine. So I'll be ordering a new motor. I'd buy a new tractor, but I need a garden tractor (terrain around my house will wear out a riding mower fast) and its a matter of principal..... LOL

To be honest, this is most likely my fault. I haven't checked the oil in a few years (which means it hasn't been changed either). The oil level was low, but not empty. This happened while I was on an incline. Maybe there wasn't enough oil to keep everything lubed and she gave way..

Man, this sucks, My daughters car got hit in Walmart and the driver left the scene(insurance covers that one), I blow my engine on my riding mower, AND my truck tranny goes out all within 10 days..... LOL

Good thing I'm made of money and can pay for all this...... LOL

From: TD
25-Jun-18
Goats. They'll keep the grass down, you can pack with em and if things get tight you can eat em..... just don't name em, makes the eating thing a bit harder.....

25-Jun-18
You may be on to something. My neighbor has a herd of them...

From: JL
25-Jun-18
Borrow your neighbor's goat. You'll feed them for free. :-)

From: Grey Ghost
26-Jun-18
I'd tear into it to confirm the problem, at least

A connecting rod for that engine is only $51. Another $10-20 for gaskets, maybe.

Just saying.....

Matt

26-Jun-18
Theres a part of me that wants to tear it apart and try to fix it. Theres an even bigger part that says "you dont have the time to mess with this. Besides in the end youll probably end up spending more on it".

From: Grey Ghost
26-Jun-18
If it's a time issue, I certainly understand. As for money, It wouldn't cost you anything to tear it down and confirm the problem. What if the problem is that little $1.69 shaft key?

At any rate, I hope you get up and mowing soon. I'm truly sorry for your string of bad luck.

Matt

From: bb
26-Jun-18
I'm having a hard time believing that it could be connecting rods based on the info provided so far.If a connecting rod broke, it would make a lot of noise when you turned the engine over as it's beating the crap out of the inside of your engine. for both pistons not to move that would mean both broke. If it's bearings, the pistons would still move when the starter was engaged. if they seized, the starter and flywheel would not turn over. If the rods were broken and wedged, same outcome as seized. I still think the issue is at the point where flywheel connects to the crank. I would bet on that keyway.

From: Grey Ghost
26-Jun-18
bb,

We agree. A broken rod usually causes major carnage inside the block. Cranking the engine with a broken rod usually causes a loud clatter with all those pieces flying around inside.

I've been thinking a sheared shaft key ever since T-Flight discovered the flywheel was turning while cranking, but the pistons weren't moving,

Matt

From: bb
26-Jun-18
Yeah, I can't think of another thing that would cause the symptoms described than the flywheel and crank not connected.

From: Solo
26-Jun-18
My experience tells me that lower end John Deere's are a piece of junk. That's because, after my loss, I investigated and found out that they pawned off their name to a number of no-name companies for a pay-off on low end equipment. And mine was one of many. TF's probably was one of those, too....

I'll never buy another John Deere as long as I live.....

26-Jun-18
After i pushed the pistons with the arrow i tried turning over to see what would happen. There were several loud clanks and then nothing. I can also freely turn the fly wheel.

Ill prob tear it apart just to see whats up. I may even rebuild it later. Im thinking of building a hover craft and could use the motor for that.

On a good note. I started clearing the food plot dite with my lawn mower. I need to cut a few trees fown but i need a new chain. Ill pick one up tomorrow.

From: JL
27-Jun-18
Have you tried to turn the flywheel while holding the crank pulley from underneath?

28-Jun-18
Just bought a used motor on ebay for 389.00 with shipping

From: TD
28-Jun-18
Conn rods normally break from bearing seizure to the crank. The aluminum "welds" itself to the crank journal, many times galling it or otherwise damaging it. Most common cause is a no oil condition. Which also means no oil to several other parts that require it. Not to mention the heat damages that aren't apparent.

IMO good call on the new/used engine. Although a used ebay engine my be a roll of the dice...... When I was a kid I used to fix up engines like the one you blew up and sell em to folks. =D

I never sold one that didn't run well though.......

From: Grey Ghost
28-Jun-18
"After i pushed the pistons with the arrow i tried turning over to see what would happen. There were several loud clanks and then nothing."

With each new bit of info the picture gets clearer.

If the crank didn't turn when you pushed the pistons down then it's definitely broken connecting rods. The loud clanks you heard was the broken half of the rods, that are still connected to the crank, banging against the other broken halves that are connected to the piston. It probably shoved the pistons back up in the bore where they remained, therefore the noise went away.

Sounds like a good score on the used engine.

Matt

From: bb
28-Jun-18
Agree GG, it's sounding more like rods now with this latest bit of info.

From: JL
28-Jun-18
I think there is a teachable moment in here somewhere.

From: Solo
28-Jun-18
Um... Don't use one of your motors to make tar from oil?

From: TD
28-Jun-18
Funny, I probably check the oil on a dozen or more pieces of equipment every.... single.... day. I can't remember the last time I checked the oil in my lawnmower at home......

From: Solo
28-Jun-18
One of my pet peeves, too, TD. I grew up racing high output motorcycles, which included building the motes I straddled at triple-figure mph's....

Let's just say, my life depended upon the life and well-being of those motors. So simple lubrication maintenance tasks are second nature to me, even after all these years gone by....

From: JL
28-Jun-18
Ha....me too. As a CG helo mech and Flt Mech for a few decades....it is part of life to check fluids before the helo flies, after it flies, before it flies again, and when you put it to bed at the end of the flying period. Alot of what I did then carries over to how I take care of things today.

28-Jun-18
You know im religious about the oil in our cars. Youd think id be the same for the lawn equipment... well i will be now!!

From: JL
29-Jun-18
You can do an engine alot of good doing regular tune ups and oil/filter changes. I use SeaFoam alot in all of my engines....especially the ones that sit for the winter like the ATV, mowers, blowers, whackers, outboard, etc.

29-Jun-18
X2 on Seafoam

09-Jul-18
ITS ALIVE!!!

Replaced the motor today. It runs GREAT!

From: Solo
09-Jul-18
Congratulations, Thunderflight!!!! Great job!

From: bb
09-Jul-18
Did you do a post mortem on the other engine?

From: JL
09-Jul-18
Good deal.....that's one way to fix her. Congrats.

09-Jul-18
Bb, nope... maybe if i have time later

From: nowheels
10-Jul-18
I've been following this thread along, but haven't posted yet. I would also be interested in the autopsy findings when you have the time.

10-Jul-18
I plan on tearing the motor down anyway. I'm going to save all the external parts incase I break the tractor again. LOL

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