Export thread

I have Poulan Pro 1842 STC that stopped while I was cutting my grass. I felt little resistance just before mower stopped. While stopping, there was metallic sound. I took apart the housing. My battery is good. My engine won't rotate by hand. When I try starting, I see that starter motor is trying to turn the engine, but it cannot. I would greatly appreciate your suggestion. Thank you in advance.
Please see attached picture.

Remove the spark plugs and try to rotate the engine by hand. If you can’t rotate by hand you have an internal problem. If you can rotate by hand, by the starter again. If it will not rotate with starter, check your battery voltage, should be 12.2-13.6 DCV

Did you check your oil level?

Scrubcadet10 said:

Did you check your oil level?

Click to expand...

Thank you! I just checked. It was low. Does that lock your engine? Nice feature. Just curious.

dmas said:

Thank you! I just checked. It was low. Does that lock your engine? Nice feature. Just curious.

Click to expand...

depends on how low... if its not between the High and Low lines, then yes, you could have seized up the engine. due to no lubrication.

dmas said:

Thank you! I just checked. It was low. Does that lock your engine? Nice feature. Just curious.

Click to expand...

I filled oil to the top. I took out spark plug and removed battery wire. Re-plugged spark plug and connected battery wire. I still can't move engine wheel and starter motor is unable to move. My battery is fully charged to 12.6. I tried with jumper cable from my car as well.
Any other suggestion is welcome? Thank you again

Scrubcadet10 said:

depends on how low... if its not between the High and Low lines, then yes, you could have seized up the engine. due to no lubrication.

Click to expand...

It was lower than low. Can you un-seize engine now? Thanks

dmas said:

It was lower than low. Can you un-seize engine now? Thanks

Click to expand...

Well, that usually causes irrepairable damage to parts, sometimes you can save one with some effort. I will let the experts chime in.

Usually no
If the top bush runs dry & the crankshaft siezes on it then that will require the crankcase to be machines and a custom bush made and fitted to the crankcase
If you or a friend can do this then it is a viable repair otherwise cost exceeds replacement
If the piston has seized in the bore this can be repaired if the damage to the cylinder is not to great
If the con rod has seized on the crankshaft then usually they can be repaired if the journal is not damaged too much
Continuing to try to force the engine to crank will only do more damage so pull it out & pull it apart .

dmas said:

It was lower than low. Can you un-seize engine now? Thanks

Click to expand...

Thank you! The seize word was a big help. I was able to un-seize based on you tube video. It is now turning easily back and forth about 1/4 to 1/2 round.
My starter motor and engine teeth are not locking properly. Should I buy new starter motor?

Once aluminum to steel transfer begins, just unjamming it will not fix the problem. All it going to do is to throw a rod threw side of the crankcase. The transfer must be removed and new parts installed. Plus you most likely find that the head gasket is blown which caused the loss of oil in the first place.

bertsmobile1 said:

Usually no
If the top bush runs dry & the crankshaft siezes on it then that will require the crankcase to be machines and a custom bush made and fitted to the crankcase
If you or a friend can do this then it is a viable repair otherwise cost exceeds replacement
If the piston has seized in the bore this can be repaired if the damage to the cylinder is not to great
If the con rod has seized on the crankshaft then usually they can be repaired if the journal is not damaged too much
Continuing to try to force the engine to crank will only do more damage so pull it out & pull it apart .

Click to expand...

I have one stupid question. Does engine rotate freely full round or just partial? I will try to pull it apart today to see what is going on. I appreciate help here. Thank you!

No
Without the plugs it should be easy to rotate but you will get resistance once every revolution from the valve springs being compressed

StarTech said:

Once aluminum to steel transfer begins, just unjamming it will not fix the problem. All it going to do is to throw a rod threw side of the crankcase. The transfer must be removed and new parts installed. Plus you most likely find that the head gasket is blown which caused the loss of oil in the first place.

Click to expand...

Looks like my connecting is broken. How do you replace it? Please see attached pictures. I was able to push piston in, and there was no issue. But now my engine doesn't rotate to push it out. Any suggestion?

tear the rest of the engine down, unbolt the sump /oil pan cover, and get all the broken pieces out.... hopefully it didn't crack the block or wipe out the camshaft when it went.
inspect the crankshaft journal that the rod bolts to, if there are any gouges and scoring marks, the crank is trash. and then you need to price all parts needed, compared to a new engine.

dmas said:

Looks like my connecting is broken. How do you replace it? Please see attached pictures. I was able to push piston in, and there was no issue. But now my engine doesn't rotate to push it out. Any suggestion?

Click to expand...

Can you open up from the top and replace or you have to remove the engine and open it from the bottom?

Scrubcadet10 said:

tear the rest of the engine down, unbolt the sump /oil pan cover, and get all the broken pieces out.... hopefully it didn't crack the block or wipe out the camshaft when it went.
inspect the crankshaft journal that the rod bolts to, if there are any gouges and scoring marks, the crank is trash. and then you need to price all parts needed, compared to a new engine.

Click to expand...

Can you open from the top? Otherwise, I have to take the whole engine out from the body. Is that right way to go?

nope, got to remove the engine.

That is a Briggs 310000 series engine. Head gasket was definitely blown. Damage inside can be minor or major just when the rod broke. I have had them to break at startup with only minor to the cylinder block but if running at full rpms take out the cylinder block and other internal items.

There will be aluminum transfer on the crankshaft rod journal. Do not use sandpaper or emery cloth to remove it. Instead use Muriatic Acid to remove the aluminum transfer then you check for journal damage. Caution Muriatic Acid can be quite dangerous use indoors as it moisture sensitive and will produce toxic fumes. You use it outdoor with good air flow away from yourself. It also the heavy fumes can damage other items nearby therefore remove all un-needed tools and equipment from the area and rinse everything once the aluminum transfer is removed. This will help neutralize the acid. Afterward oil everything to prevent flash rusting.

And of all things don't get it on the good aluminum areas as it will destroy the aluminum. Plus always seal the acid container so soon as possible as it will produce vapors just sitting there open.