Well Rusty, I think you let your finger linger a little too long on the H but no, you do not need to remove the head. You do need to determine why the push rod broke. It is typical of the aluminum push rod to wear a place about an inch down from the rocker arm and, if not reversed in time, bend or break. IF this is what happened, no worry, just put in a new push rod and adjust.

Sometimes the valve guide on these engines will come loose, work up until the valve spring retainer hits it and bends or breaks the push rod. IF this is what happened then some other things need to be done.

I know you have been at this a long time and assume you have the valve adjustment instructions for this engine, just checking.

Walt Conner
wconner5 at verizon dot net

You can purchase a steel push rod as a replacement. Doesn't cost that much ~ $4. However if you do some research on B&S V twin OHV engines (Intek) - assuming that is what you have - you'll see that it is a recurring problem and if the guide has moved it will likely run more $$ to fix than it is worth it.

B&S put steel and aluminum push rods in their sequence for a reason and it was not cost, actually the aluminum push rod costs more than the steel.

I have a fix for loose valve guides that has been tried by several people with only positive feed back, cost, new head gasket.

The model number given was a 31 series which is a single cylinder OHV engine.

I have been in direct contact with Rusty and I think we have things in hand.

Walt Conner

Walt: I got a new aluminum push rod, installed it into the proper hole, and tried turning the crankshaft, to make sure it is ok. BUT!! It isn't OK! The push rod doesn't go up and down! Not even with the rocker arm on it! Nor pushing on it to make it follow the cam!
So, now what?
I called the owner, and he doesn't know what he wants to do with it as far as fixing it. I don't want to tear it down unless absolutely necessary. The tractor is an old Sears, dark green, so you know it isn't new, nor near new. It has had a hard life, with little or no cleaning or much of anything else! I have several used motors here, but i'm just waiting to hear what he wants to do.
Thanks for your advice and information! And, i also got the info from Mownie, so i am well fixed for info.
Thanks: Rusty Jones
The engine number is:31H777020E1 and: 30514ZE30465

"Walt: I got a new aluminum push rod, installed it into the proper hole, and tried turning the crankshaft, to make sure it is ok. BUT!! It isn't OK! The push rod doesn't go up and down! Not even with the rocker arm on it! Nor pushing on it to make it follow the cam!
So, now what?"

Rusty, put the push rod in the socket of the cam follower. You are not the first one to miss it.

Walt Conner

After looking back at your original post, I see it is a 31 series which is susceptible to camshaft lobe failure but since the push rod broke, it hardly seems likely that the cam lobe was completely worn off.

You never did say if the push rod was badly worn where it broke.

From the IPL it looks like that camshaft is one that is made up of components rather than one pc. cast. I guess it is possible the Intake cam lobe dislodged from its' serrated area of the shaft, never heard of this happening. IF there was that much pressure put on it, then it had to be caused by something else, didn't I mention about the valve guide coming loose and coming up to where the valve spring retainer hit it? Did you check that?

Walt Conner

Walt: I tabled the whole thing until Monday--I'm going bluegrassin tomorrow morning, coming back on Sunday. And, the owner bought a tractor to replace that one, since his Sil knows a lot about tractors, and i got the old one!

Walt: Well, i'm back from several sleepless nights, out pickin my 5-string banjo at a bluegrass festival, so tomorrow i'll get down there to inspect it further.
What part does the rectangular black plastic piece, that the valve push rod goes down thru, play? Is that the valve guide? It looks normal, not broken, or out of position. When i rotate the crank-shaft, the valve pushrod doesn't move up or down. I have another engine here that will go into that tractor, if i can't find out what is broken inside, without a tear-down. Could it be a broken cam-shaft? Could the cam follower have fallen out of its hole and into the sump?
I won't be able to work on it tomorrow, i have a memorial service to attend, my wife just reminded me. I'd better get to bed-don't want to look like a zombie at the service!
Rustyj

The plastic thing is not a valve guide, but it is a pushrod guide. No, the lifter can't fall out. The camshaft has to be removed before the lifters can be removed from their bores.

Here is a link that might be useful: 31H777 IPL

Hey Rusty, sure wish I could have heard you pickin and seen the grinin.

You never have said if the exhaust valve works. Not likely the camshaft is broken and if the exhaust valve/pushrod works, it isn't.

I still think you simply missed the socket of the cam follower, try feeling again, for the socket in the cam follower that is.

These engine have a history of soft cam lobes as I think I may have said but it sure as heck isn't going to wear to the point there is no movement.

Walt Conner

Walt: Yep-i missed the cam follower! Tried again today, and igot the rod to move up and down, keeping pressure on it.
tomorrow morning, i'll get it all adjusted and try to run it! Thanks for all of your help!
Rusty J (A much smarter Rusty J.)

Yesss!! put it back together, and it runs and drives! YESS! And stays running and has power and it RUNS!! And it MOWS!! And, it is late, and i'm going to go to bed! Tomorrow i clean it all up, and polish it, and set it out under cover, for sale!
Thanks to all for your help and instructions!
by: Rusty Jones

I know this is an old thread but I have the same issue on a Craftsman LT1000 with a b&s 16.5 hp OHV engine. Mouse built house in engine shroud, worked for 2 cuts and slowed and then died while cutting. All indications pointed to valve gap realignment. May or may not have had valves in the right place when gap adjusting to .004. Didn't start. Went back in and pulled the push rods and found the lower rod (intake) was bent. Replaced it but now it doesn't move. I tried to reseat it like 10 times since I thought improper seating is the only reason it wouldn't move. But there are only so many ways you can pace the pushrod. Now I think it's something else. Any guidance? -Mike

You really should have started a new thread. You may have more than one problem. Why did the push rod bend? Was it badly worn OR has the valve guide slipped up to where the valve spring keeper is hitting it? I have a fix for that.

IF the engine was running and now the Intake push rod does not move at all, you are still not hitting the lifter socket. Camshaft will not go completely flat instantly.

Walt Conner

What would happen if i mistakenly put the alum push rod where the steel one should have been and visa versa. can i simply use two steel rods? i forget which ordr they were in.

On an Intek, the aluminum rod is on the intake.