"Where would you start? I don't want to spend too much time on the blades for a motor that wont start." That is a question that could go both ways really. It shouldn't be possible for the blades to hit one another on your unit.The deck should come off for an inspection. The engine should be re-secured . Back to the question at hand, It can be possible that hitting the root there is a connection. With conditions being right, a flywheel key can shear causing a no start condition- much like a walk behind. The loose engine also can wear into wire harnesses that come around the corner of the engine or wiggle a connector apart. Or simply you have a situation something else happened all together at an inopportune time.
Are you mechanical enough to look over such things, maybe check for spark to get a handle on what is happening? We would be glad to help if you are. Post back the model #s from the mower and engine if you wish and with luck the posters here can help get you going again.

I would take the mowing deck off the tractor, and take the blades off the deck and see if they are bent. You may have trouble getting the blade off that hit the root as hitting something with a blade will tend to over tighten it. Look at the mandrels where the blades connect to the deck. Look close as one may be cracked and when power is applied the blade may wobble and might be hitting the deck. This happened to me once on a Snapper LT11 I used to own.

With the deck off see if it will start. Good Luck!

Runninbg over the root was a red herring. Bladed checked out OK.

Engine was low on oil, almost dry.
Loud clanging noise before we stopped it - thrown rod maybe.
I added oil
I took out spark plugs and made sure the main pulley would spin; it did after some working.
When cranking, air comes out and the pulley does spin.
Put plugs back in, still wont turn over
Its a B&S Model 46070 type 2278E1

Any chance of saving, any tests to determine how far gone it might be.
Thanks

On any air-cooled 4 -cycle engine, it is highly advisable to check the oil EVERY time before cranking the engine, no matter how brief the shutdown preceding the cranking.
Sounds as if the mower in question has multiple issues, not necessarily directly related to each other, but all becoming evident in the same general time frame.

Your Briggs model number seems to be missing a "digit".
Is the number actually maybe 446070, or maybe 46x070 (x being unknown numeral). Or even some other 6 digit number.
Briggs model numbers are 6 digit numbers, except for the very smallest displacement engine families.
I would certainly hope any rider cutting 42" will have more than 4 cubic inches of engine displacement. :^)

Anyhow, I will surmise that the engine has actually broken a connecting rod.
To determine this you would need to remove the spark plugs and WATCH the piston by looking into the spark plug holes with a flash light. Crank the engine (or turn by hand) and watch each piston for motion. One of the pistons may not be moving. If a piston is not moving, but the engine crankshaft is turning.................that connecting rod is broken.

Only a tear down and look see will disclose the extent of the damage.
Oil is cheap.......even if it's $10 per quart, compared to the lack of oil.

This post was edited by mownie on Wed, Jul 31, 13 at 12:23

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