Pulled the # 1 head, exhaust push rod on # 1 cylinder is nowhere to be found, its gone....and its steel, intake is aluminum.
B & S Intek VTwin 23 hp. mod.445577-0499-E
Do believe the last time I ran this beast I had not torqued the fly wheel down enough. Made a terrible sound before it quit. Will be removing engine from tractor to work bench.
Not gonna like what I'm going to find.
Ah the infamous missing push rod. It happens quite often on this engine.
Normally it's from a slipped valve guide that caused the push rod to bend and pop off in the first place but it can happen without any actual head damage but always be cautious and trying to repair it because normally there is a reason to push rod bent and disappeared in the first place.
It will be bent in an S shape and inside your crankcase.
Use a bright flashlight and a small magnetic pickup tool and you might be able to reach in there and find it but I've never been that lucky well maybe once.
I have repaired a number of these, once even and a guy's backyard while he watched.
It only takes about 12 minutes to pull the engine from the machine and then you should drain the oil out of it so it won't make as much of a mess.
I think there's 13 bolts that hold the base plate on.
So you should clean all that up really well or blow it off with compressed air or a good stiff brush and take the bottom off and you'll be able to get the push right out of there..
Then you can look around and see if there's any damage which there probably won't be just make sure there's no other metal pieces and they're floating around or whatever. I like to run a magnet around.
And then you can put it back together but be cautious...
You have to pull the 35/16 bolts off of the oil pump cover and take the oil pump gear out before putting this base plate back on are you risk a great chance of jamming up the oil pump by it not lining up and then you will have no lubrication and once you start and run it it will lock up and snap a rod in about 1 minute or two.
Once you have the bottom sump back on and torque down with a new gasket preferably but if the old one doesn't come apart too badly you can clean it and use some RTV anywhere it rips or a thin smear around it then, you can drop the oil pump gear and drive shaft back into place and put the flat metal cover back on.
Now you have to fix whatever the problem was the first place which is probably a slip is exhaust valve guide from overheating because that head probably had a lot of grease or grime or grass or nest build up on it.
You don't have to replace a head even though that's the official fix for a slip valve guide and pop exhaust valve seats and I can almost guarantee that after I fix one it will be stronger than the original was or the new one you can buy.
You have to put some rope or something in the cylinder and slightly rotate the Piston up to touch it to push to keep the valves mostly closed and then take the valve stem spring retainers and keepers and spring off of that valve.
Then you were really see how the guy is pushed out and why the rocker arm can't push that one down as far as the other one but you get also inspect this before you take anything apart by pushing with your thumb and looking with a bright flashlight.
Then you have to clean it up really well, I prefer carb cleaner to get all the oil off of it, and then I like to use red loctite even though it might not make any difference, it makes me feel better.
So I slather it with a good amount of red loctite but make sure I keep the lock tight off of the actual valve stem and then I drive it back into it's approximate proper position by tapping it with a hammer..
It won't take much because they're not very tight which is the problem to begin with..
You have to make sure you don't go too far but you can kind of gauge it from the other one or even look at the other head.
Then the key is you have to stake it.
You can even use some old school machine shop ideas and you could drill it and pin it but that's probably not necessary.
Staking involves using a punch or I prefer to use a number two Roberts square Drive bit and go around like 10:00 position 12:00 6:00 3:00 9:00 and then do the other ones in the middle of those and stake it with a hammer and your bit so you're pushing into the aluminum pushing it towards the valve guide so it's tightening it up.
You kind of have to get good at it and do it just the right position but it is easier on a valve guide than it is on a valve seat but once you do all this and the lock type probably helps, I've never had one move again.
So then you've got the engine back together and you've got the head fixed that was the offender in the first place so now you just have to put the new push rod in unless you're crazy enough to hammer it back into place and get it mostly straight which can be done but I don't recommend it.
Then you have to turn the engine over to get it on top dead center of the compression stroke and then turn it until the Piston goes down one half inch past that point and then you have to adjust both push rods which is kind of a pain in the butt on the bricks because it takes three or four times to get them just right.
Then you put the valve covers back on and you're done.
I always Mount the engine back to the machine after I get the base plate back on and I do the valve guide repair and adjust the valves with it on the mower.
It's really only about an hour and 15 minutes start to finish but that's when you have all the tools already out and ready to go because you've done it many times.