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I picked up a Murray push mower with a B&S 5.0 motor. Mower looks like it's never been used. However the motor is seized. Can't pull the cord at all. I have no idea what to do. Any suggestions would be great.
Thank you
Brenda

First thing to do is check the oil level, no oil probably seized. Has oil may be seized, but need to check further. Remove the spark plug and try again with no plug. If it turns over reinstall plug and try again. Let us know the results of you tests and we’ll tell you how to proceed. When you post back include the model, type and code numbers stamped on the engine cover.

Rivets said:

First thing to do is check the oil level, no oil probably seized. Has oil may be seized, but need to check further. Remove the spark plug and try again with no plug. If it turns over reinstall plug and try again. Let us know the results of you tests and we’ll tell you how to proceed. When you post back include the model, type and code numbers stamped on the engine cover.

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Before I tried to start it I checked the oil. I was surprised the oil was so clean. Looked like it had just been changed.
Took spark plug out still couldn't pull cord.
Model. Type. Code
124702 - 3106-01. 92032156
Thank you your help

Sounds to me that the mower was run without oil. After it seized the user put in fresh oil to hide their mistake. Sometimes these units can be saved, but your odds are 50/50. If you want to give it a try, this is what I would do. You really have nothing to lose.
1. Remove the spark plug.
2. Tip the mower on its side, carb/air filter up.
3. With gloves on try to turn the blade backwards, meaning you are pushing again the sharp edge.
4. If this doesn’t move it, take a block of wood against the cutting edge and give it a few good whacks with the biggest hammer you have. If it is not seized too bad it should free up.
5. If you can’t get it to move you are out of luck, junk.
6. If you free it up and it moves freely, tip the mower back up and pull the recoil a dozen times, no plug.
7. Install the spark plug and see if it starts.

Make sure the engine brake cable (EBC) is releasing the flywheel brake. Or if the cable is not present make sure that the brake is crippled.

These engine brakes are often overlooked as a possible failure point.

Thank you Star, it come so natural that I forgot about that.

Oh and welcome to the forum.

what has already been said and, when was the last time it ran, and where has it been sitting since then? Is this a new mower to you? What is the history of maintenance on it?

Rivets said:

Sounds to me that the mower was run without oil. After it seized the user put in fresh oil to hide their mistake. Sometimes these units can be saved, but your odds are 50/50. If you want to give it a try, this is what I would do. You really have nothing to lose.
1. Remove the spark plug.
2. Tip the mower on its side, carb/air filter up.
3. With gloves on try to turn the blade backwards, meaning you are pushing again the sharp edge.
4. If this doesn’t move it, take a block of wood against the cutting edge and give it a few good whacks with the biggest hammer you have. If it is not seized too bad it should free up.
5. If you can’t get it to move you are out of luck, junk.
6. If you free it up and it moves freely, tip the mower back up and pull the recoil a dozen times, no plug.
7. Install the spark plug and see if it starts.

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The hammer and wood worked! It's free! I'm so excited. Thank you all so very much!
I'll have to run out and get fresh gas and see if it will try to start.

sgkent said:

what has already been said and, when was the last time it ran, and where has it been sitting since then? Is this a new mower to you? What is the history of maintenance on it?

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I have no idea the last time it was started. No idea if any maintenance was done to it. It's a older mower but looks almost new.
I picked it up last Fall. Checked the oil, put gas in it and tried to pull the cord. Couldn't pull the cord at all. Disnt want to break it so i emptied the gas out put it up and here I am.
You guys are great! Thank goodness for forums and you people helping dummies like me.

slomo said:

Oh and welcome to the forum.

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Thank you!

i'd be spraying a couple squirts of penetrating oil thru the spark plug hole down the cylinder walls because it sounds like the piston rings were rusted to the cylinder. Running that without some lubrication will only tear up the rings.

sgkent said:

i'd be spraying a couple squirts of penetrating oil thru the spark plug hole down the cylinder walls because it sounds like the piston rings were rusted to the cylinder. Running that without some lubrication will only tear up the rings.

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I'll do that. Thank you.

If you try putting oil in the cylinder do it very sparingly. Now that it is free really don’t need to, as the engine oil will start doing its job. To much oil at this point will not allow the plug to fire.

Rivets said:

If you try putting oil in the cylinder do it very sparingly. Now that it is free really don’t need to, as the engine oil will start doing its job. To much oil at this point will not allow the plug to fire.

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OK thank you.

Because you were able to free it up using a block of wood and hammer, I suspect that the rings are fine and that the rod was probably frozen on the crankshaft. If you get it running I suggest you change the oil after 2 hours use to remove any debris in the oil. No need to put any oil in the cylinder, just my opinion.

Rivets said:

Because you were able to free it up using a block of wood and hammer, I suspect that the rings are fine and that the rod was probably frozen on the crankshaft. If you get it running I suggest you change the oil after 2 hours use to remove any debris in the oil. No need to put any oil in the cylinder, just my opinion.

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Thank you

Safehorses said:

The hammer and wood worked! It's free! I'm so excited. Thank you all so very much!
I'll have to run out and get fresh gas and see if it will try to start.

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Glad you got it to rotate. Keep an eye on the oil level after you run it.

Rivets said:

Sounds to me that the mower was run without oil. After it seized the user put in fresh oil to hide their mistake. Sometimes these units can be saved, but your odds are 50/50. If you want to give it a try, this is what I would do. You really have nothing to lose.
1. Remove the spark plug.
2. Tip the mower on its side, carb/air filter up.
3. With gloves on try to turn the blade backwards, meaning you are pushing again the sharp edge.
4. If this doesn’t move it, take a block of wood against the cutting edge and give it a few good whacks with the biggest hammer you have. If it is not seized too bad it should free up.
5. If you can’t get it to move you are out of luck, junk.
6. If you free it up and it moves freely, tip the mower back up and pull the recoil a dozen times, no plug.
7. Install the spark plug and see if it starts.

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Check to see if the handle bars are extended My son got a mower and the handle bars were not and the blade was hitting againbt them so he couldn't pull the rope

Safehorses said:

I have no idea the last time it was started. No idea if any maintenance was done to it. It's a older mower but looks almost new.
I picked it up last Fall. Checked the oil, put gas in it and tried to pull the cord. Couldn't pull the cord at all. Disnt want to break it so i emptied the gas out put it up and here I am.
You guys are great! Thank goodness for forums and you people helping dummies like me.

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You aint so dumb you knew where to go to get the answer to your question and a solution to your problem.

several videos how to fix these mowers locked up.

Great that you got it to move, never seen a new motor locked up, maybe 1st owner tried to start it without putting oil in motor because motor does not come with oil in it from factory but will be in box.

This was 1 year after the first repair

It sounds as if the mower was purchased and started without oil, after it stopped the owner then added the oil he was supposed to have put in before starting it. If that is what happened the connecting rod seized to the crankshaft, the connecting rod overheated and deformed causing the bolts to loosen. If this is what happened the bolts will backout after a few hours and you may have an inspection hole in the crankcase.
I explain this because I have seen this happen. By the way it will also scuff the clyinder/piston.
I do hope I am wrong but be aware it may happen.

Boy....I'll bet the rings and cylinder really appreciate not being looked at.

Safehorses said:

I picked up a Murray push mower with a B&S 5.0 motor. Mower looks like it's never been used. However the motor is seized. Can't pull the cord at all. I have no idea what to do. Any suggestions would be great.
Thank you
Brenda

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First I'd suggest you don't use the pull cord for all of these attempts at starting it. Simply reach under and try to move the blade by hand so you don't get the rope unnecessary tight or worse break the pull string or the assembly itself. That said, it might sound silly but have you tried to spin the blade by hand? If it doesn't move then pull the plug and try again. If still no then pull off the starter string assembly. Should be 3 or 4 screws right on top. That'll make sure it's not an issue with the pull cord assembly binding up.
So now this is where I say you would do best by looking at it for what it is, a possibly blown mower you got for cheap and do the following. Assuming it's still not moving I would say put a small amount of oil in the cap from a quart of SAE 30 and pour it in the spark plug hole. Put the plug back in finger tight and leave it alone for awhile. Then pull the plug back out and try to move the blade if still no go then you probably have your answer but if it were me and it was my mower I would take a small wooden dowel rod as big as you can fit into the spark plug hole without binding and simply apply pressure as you're simultaneously trying to move the blade by hand.

Mezman said:

First I'd suggest you don't use the pull cord for all of these attempts at starting it. Simply reach under and try to move the blade by hand so you don't get the rope unnecessary tight or worse break the pull string or the assembly itself. That said, it might sound silly but have you tried to spin the blade by hand? If it doesn't move then pull the plug and try again. If still no then pull off the starter string assembly. Should be 3 or 4 screws right on top. That'll make sure it's not an issue with the pull cord assembly binding up.
So now this is where I say you would do best by looking at it for what it is, a possibly blown mower you got for cheap and do the following. Assuming it's still not moving I would say put a small amount of oil in the cap from a quart of SAE 30 and pour it in the spark plug hole. Put the plug back in finger tight and leave it alone for awhile. Then pull the plug back out and try to move the blade if still no go then you probably have your answer but if it were me and it was my mower I would take a small wooden dowel rod as big as you can fit into the spark plug hole without binding and simply apply pressure as you're simultaneously trying to move the blade by hand.

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At this point what's the worse that can happen right?

Safehorses said:

The hammer and wood worked! It's free! I'm so excited. Thank you all so very much!
I'll have to run out and get fresh gas and see if it will try to start.

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The one thing not mentioned often enough is the TYPE of gas used. I've been using ONLY premium 91 or 92, ethanol free if you can get it in your state! Using this high octane fuel utilizes the additive package best, which is 10x more than in regular unleaded!

Brenda,
You have received advice from several people on the forum. I am not going to tell you how to start your engine ,BUT I do want to give you a very important warning. You are not a mechanic and you are probably a novice around mowers. DO NOT pick up the wheels off the ground until you have pulled the wire off the sparkplug. Double check yourself ! If not, turning that blade is like cranking an airplane. Should it start you have a meat slicer in front of you. BE SAFE. We don't want anyone hurt.

Hi from what I read not one person said to put a penetrating type oil in cylinder. setting it up so the spark plug hole is strate up with like marvel oil or gibbs penetrating oil And let sit over nite before trying the medfords others subjected all needed to free it up ! if it turns it should run But the damage has been done so it smoke till it burns off the oil that freed it & will use oil going forward ! so just keep an eye on oil level ! enjoy till it breaks

Ever heard of using de-carbonizing fluid?

I thought I'd share my 2 cents. If the cylinder and rings were not the issue, and it was the rod freezing up on the crank, I'd offer the following caution (that comes from experience). My experience with this is you can free it up and think all is good but beware! Every engine I've repaired with a frozen rod has left aluminum deposition on the crank due to the excessive heat which caused the problem in the first place. This does not go away on its own when you free up the rod/crank and should be removed by whatever means you choose, i.e. polish, acid, combo etc. and the rod replaced for proper journal clearance. If you don't, and merely get the rod loose, even with proper oil levels, the irregular finish between the rod and crank will overheat again and it won't last.

I experienced this a year ago with a JD 105 lawn tractor running a 17.5 BS. As this engine design is prone to do, the head gasket blew and the customer was not watching oil levels and it froze up. With some prying on the flywheel with a bar, he was able to free it up. He changed the head gasket and changed the oil/filter and filled to proper level. Started and sounded fine. 35 minutes into his 1st cut, it grenaded with catastrophic failure. When I got it and did the autopsy, the piston, rings and cylinder wall were just fine. This time the rod came apart at the crank journal and a whole bunch of ugly took place. I put a brand new engine in it!

Do you guys agree that the frozen rod repair should include polishing the crank and replacing the rod?

Good luck ... just one old-timers thoughts!

When you have aluminum transfer the steel crank you should use Muriatic Acid to remove the aluminum transfer and replace the connecting rod(s).

Note Muriatic Acid is dangerous and should only be used outdoors, then neutralize after use, and the steel oiled to prevent flash rusting. Muriatic Acid can take your breath away so always be up wind of it.

I put a new spark plug in it. Added fresh gas. After 5 pulls it started. Thank you all so very much! I now have a working mower. I'm so excited

Safehorses said:

I put a new spark plug in it. Added fresh gas. After 5 pulls it started. Thank you all so very much! I now have a working mower. I'm so excited

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I was wondering how it was going? Great news! Wish you all the best!!!

Glad to hear life is good. May I suggest that you change to oil after about 5 hours of use to remove any debris from the sump. Totally up to you.