Hit a stump, mower died, need help troubleshooting please.

I am back! We are in the middle of selling our house, so I have been pretty busy.

I managed to get the brakes unlocked by tapping on the components with a wrench. Then pushed it up into the garage.

I removed the valve cover and to my dismay, both valves are stuck open. No play whatsoever in any part of those components. I tried rotating the flywheel (which is stiff) and there is no moving at all in the valves. I tried moving the valves by hand, but they will not budge. I removed the spark plug, rotated the flywheel, and see that the piston is moving inside properly. Removing the spark plug and releasing compression made no change in the valves either. I do not see anything in the valve assembly that look broken or detached. The push rods are in position and intact.

Two people locally said on the phone that it is likely a broken/damaged camshaft and that it would be more cost effective to buy a new engine. I wanted to check with all of you first to see if maybe there are some things I can check before I throw in the towel. I have not removed any part of the valve assembly (I hope that terminology is ok) yet. Any ideas?

It is quite possible that you have damaged the gear on the camshaft, only way to tell is for you or someone to take it apart and have a look...!

I am poking around a little more. I removed the pushrods and they appear to be straight and undamaged. With the outer components off, I was able to push a little better on the valves. They actually do move slightly, but they are stiff/spongy feeling. They do not move easily. What is normal? The stiff spongy feeling or should it move more freely? I thought they didn't move at all before because I was not pushing hard enough.

Would there be any benefit to remove the head and have a look in there, based on my troubleshooting thus far?

If the problem is, in fact, something related to the cam, do I have to remove the entire engine from the mower to get to it? Or can it be worked on in place? I have been looking for videos and can't find any that begin from the very beginning. Everything I am finding shows people working on engines they have already completely removed and disassembled.

Some direction would be much appreciated. Thanks!

Unfortunately you will have to remove the engine. we will need the engine number and type to be able to help you out, I don't see it in any of the post, unless am missing out somewhere.

Once the push rods are out of the equation the valves will be able to move by pushing with your fingers.... They will be a lil hard to press since they have springs......

Tes you need to take the engine off the mower and the main pulley has to come off... If you do all that work you are almost halfway there.. The cam is easily changed and only the sump cover has to come off......

Now if the crank is toast then a new engine is the way to go.... Wish you were in my area.....

Thanks for the info. I am not sure why I had assumed the valves would be easier to push. Makes sense that they would be resistant. Oops.

31P677-0912-G5 Briggs and Stratton

Other than sockets, ratchets, wrenches and parts/gaskets... do I need any special tools? I do not have an impact wrench.

If I have everything I need and move efficiently, this shouldn't take more than a few days to take it apart and replace the crankshaft or gear (if necessary)?

Should I put the valve assembly back together and the valve cover on before taking out/opening the engine? Or should I leave the valve cover off for further testing while taking the engine out?

Does anyone know of a good video for removing the engine from the mower and then opening it up to get to the camshaft? I have always been somewhat mechanically inclined and am sure I can use common sense to remove the engine. But I know there can sometimes be things you should or shouldn't do to make the process easier or avoid problems.

AFProdigy said:

Thanks for the info. I am not sure why I had assumed the valves would be easier to push. Makes sense that they would be resistant. Oops.

31P677-0912-G5 Briggs and Stratton

Other than sockets, ratchets, wrenches and parts/gaskets... do I need any special tools? I do not have an impact wrench.

If I have everything I need and move efficiently, this shouldn't take more than a few days to take it apart and replace the crankshaft or gear (if necessary)?

Should I put the valve assembly back together and the valve cover on before taking out/opening the engine? Or should I leave the valve cover off for further testing while taking the engine out?

Does anyone know of a good video for removing the engine from the mower and then opening it up to get to the camshaft? I have always been somewhat mechanically inclined and am sure I can use common sense to remove the engine. But I know there can sometimes be things you should or shouldn't do to make the process easier or avoid problems.

Click to expand...

Time to get the popcorn and a note pad.
the tool you have omitted is a camera and by prefference a real digital camera not your phone.
Take a photo of what you are about to remove before you take it off then from the same position after you take it off.
Thus you can just work through them backwards when it comes to putting it back together.

Only really hard thing to shift will e the flywheel bolt ( you have done that already and the PTO bolt on the pulley )

The only people I recommend on the web are :-
Donny boyhttps://www.youtube.com/results?search_query=donny+boy+73
Taryl https://www.youtube.com/results?search_query=taryl+fixes+all

THe downside is they both have very big channels so you will have to search through a lot of videos to find what you need.

Both of them are professional mechanics so everything they show you actually works and nothing they do will or can damage the mower in order to save a few minutes.

Thanks! I had actually been watching Taryl's videos for a good part of the day. Very helpful. I found some others too, but his are definitely straight forward. This really does not look overly complicated. Hopefully all I need to do is replace the camshaft and then can move on with the joys of mowing. Fingers crossed there are no horrors yet to be discovered in there. Ha!

I will let you all know how it goes.

Do I have to remove the whole intake manifold? It looks like the throttle control cable is connected over there. I am not sure how that cable disconnects.

Does anyone know what size star (t) bit is needed to remove the exhaust from the front of the mower/engine? I have a bunch of those, but they are too small. I can't find a diagram for that specific thing.

The bolt that holds the belt wheel on under the engine should rotate counter clockwise to remove, correct? Do I need to know anything special before wrenching on that? I was going to put nylon rope into the spark plug hole to brace everything from rotating.

bertsmobile1 said:

Time to get the popcorn and a note pad.
the tool you have omitted is a camera and by prefference a real digital camera not your phone.
Take a photo of what you are about to remove before you take it off then from the same position after you take it off.
Thus you can just work through them backwards when it comes to putting it back together.

Only really hard thing to shift will e the flywheel bolt ( you have done that already and the PTO bolt on the pulley )

The only people I recommend on the web are :-
Donny boyhttps://www.youtube.com/results?search_query=donny+boy+73
Taryl https://www.youtube.com/results?search_query=taryl+fixes+all

THe downside is they both have very big channels so you will have to search through a lot of videos to find what you need.

Both of them are professional mechanics so everything they show you actually works and nothing they do will or can damage the mower in order to save a few minutes.

Click to expand...

You mention the flywheel bolt. Does the flywheel need to be removed for me to look at/replace the camshaft? I don't see anyone doing anything with that in any of the videos about replacing camshafts.