Mower engine won't turn

[Door]

I have a Ariens mower with a Briggs & Stratton Intek mower. It appears that the crankshaft will not turn. Here is what happened and what I know so far.

I took out the mower for the first time this season. Usually the mower takes 2 or 3 pulls to start. After the 2nd pull I realized that my allergies and headache had the better of me and I was not pulling the rope very hard. So I tried again. The rope came out as usual, the engine didn't start, and the rope went back in. So I grapped it again and when I pulled I found that the rope would not come out. Turns out it won't budge.

I assumed that the rewind starter had somehow gotten fouled up since I think in trying to pull hard I pulled too far and the rope handle flew out of my hand.

Turns out the rewind starter is just fine. I removed it and it seems ok. So, I held the bail brake and tried turning the flywheel (both with the plug in and with it out) and it won't turn. Next I checked that the flywheel brake was actually disengaging. It appears to work fine. When the bail brake is held, the flywheel brake disengages. However the flywheel will not turn. I still have the flywheel cup and nut attached, so I am assuming that the crankshaft is not turning for some reason.

I am very new to engine repairs. So, I could be missing something basic here. The part that has me really curious is how could the crankshaft get stuck from just pulling the rewind cord. Note that the mower previously was working fine and in the first few attempts at starting, the cord pulled normally. Since I was not feeling well, I know it is impossible that I pulled the cord extremely hard. So it doesn't seem that I could have bent the crankshaft.

Anyone have any suggestions as to what the problem could be?

Thanks, Door

[ransley]

Take out the plug, and turn it by the blade, is plug wet like it is flooded. Is oil level normal, to high and the float might have stuck and hydro locked it up with gas. Once I saw a motor so full of gas when the plug was removed and cord pulled gasolene shot out 10 ft out of the spark plug hole.

[Hipupchuck]

He already said he tried it with the plug out and it was still locked. What part of that didn't you understand?

[door]

Plug is out and is not oily or wet. Also, the blade does not turn either. I should have mentioned that. You can not turn the blade, pull the cord when fully assembled, or manually turn the flywheel or cup that attaches it to the crankshaft.

The oil is just above the fill line. So, it is about time to add more oil, but the oil is not low (as in not below the fill line).

[DanG]

Remove the spark plug. See if you can turn the engine with the blade, you have much more leverage there. Make sure you do have the engine stop disengaged. If the motor is locked up at this point, it may have a broken crank or threw the rod or its cap. Time to get another.

[ransley]

I read it butt head, he didnt try pulling the blade. What part of hydrolock do you comprehend, non I see.

[ransley]

If oil isnt overfull, and you cant move anything, something seized or broke, it may not be trashed but will be work to figure it out.

[E Z Peaces]

Without ignition, I don't know what could have happened inside to keep the crankshaft from moving either way.

I'd look for external jamming. Ignition? Drive mechanism for the wheels? If I still couldn't find a problem, I'd start removing the brake.

[clare]

Had the same problem last week on a friend's Honda mower. He hadn't washed out the deck in 10 years, and the built-up grass deposits had dried out over the winter and flaked loose, jamming the blade tight in the deck. Tipped it over, pulled out hald a bushel of hard dried grass and it started furst pull.

[clare]

Hydrolock cannot exist with the plug out.

[clare]

IF the blade is not jammed, or the blade brake is not stuck, sqirting a good penetrant in the plug hole might free it up. I've had badly seized engines (from rust on the rings) come free with a mixture of deisel fuel and oil of wintergreen. 1 ounce of oil of wintergreen from your local compounding pharmaist in 1 gallon of deisel will free up a lot of small engines. The stuff is poisonous so you have to sign for it.

[E Z Peaces]

I wonder if the diesel fuel would have worked as well alone.

CRC penetrating oil and Marvel Mystery Oil used to have a little wintergreen for fragrance. It seems to me that if wintergreen freed rusty parts, most penetrating oils would have substantial amounts.

The evidence seems anecdotal. One man swears by it because he tried two penetrating oils on a rusty fastener and it didn't come loose, but it came loose after he applied wintergreen. Who's to say it wasn't the oils he applied earlier? Or maybe the wintergreen smell gave him strength!

I wonder if it has ever been tested objectively, such as 20 similarly rusty lugnuts, 10 treated with wintergreen and 10 with Liquid Wrench, then unfastened with a torque wrench.

Plants produce it as an insecticide, and the odor attracts predatory insects to eat the pests. The typical fatal dose for adults is .5 g/kg. That would be 50g, or 8 teaspoons, for a 100 kg man. The minimum lethal dose for children is .17 g/kg, or less than a teaspoon for a 20 kg child.

[Hipupchuck]

You can't hydrolock with the plug out.

[Hipupchuck]

Someone else may have run it after you put it away and blew the engine.

[Stormin Mormon]

I'd want to take one last look at the brake (strap around the flywheel). To be certain sure. If the brake is releasing, and the mower is still locked up, then it's likely not worth fixing.

[Stormin Mormon]

Copied text: "After the 2nd pull I realized that my allergies and headache had the better of me and I was not pulling the rope very hard. So I tried again. The rope came out as usual, the engine didn't start, and the rope went back in. So I grapped it again and when I pulled I found that the rope would not come out. Turns out it won't budge."

Sure looks to me like the engine locked up between the second and third pulls. If someone else killed the engine, it woulda been locked up before the first pull, you think?

[Ulysses]

Is the blade tight?

Have you checked to see if the ignition coil is out of adjustment and jammed against the flywheel?

[Ralph Mowery]

Does it really make much differance in how hard the rope is pulled on the small gas engines ? I have a 5 kw generator and it will take two or 3 pulls to start every time. If I just pull it slow or as hard as I can. Maybe the hard pulls went out when the easy start/low compression came out.

[E Z Peaces]

With some engines a hard pull works better. Ignition and carburetion may work better with a hard pull.

[Johnl]

I don't think anyone has suggested this yet but please disconect the spark plug before trying to turn the motor with the blade. You will need your fingers for the future. This is not a fix for your problem, but a safety issue.