[Bus Driver]

Craftsman 24 HP Intek 2-cylinder, Model 4455677 Type 0827 E1, Code 0708 10YG. About 570 accumulated operating hours.
Started barely running-- took to independent shop. Said "bent" pushrods. Replaced them. Ran for less than an hour and same problem. He repaired it again. Ran for about 5 hours and same problem--but worse. So I now know that this fellow needs some help.
Researched the problem on YouTube and with Google. Google found this forum.
Mention of Walt Conner having developed a fix involving machining. Could not find details-- none of the links or email addresses worked.
Now am convinced that the problem is loose valve guide(s).
Could someone please direct me to details of the fix devised by Mr. Conner and any other durable repairs of which you are aware?
Has Briggs made effective changes to the newest replacement cylinder heads?
Your help is very much appreciated.

 

[mrshaft696]

Craftsman 24 HP Intek 2-cylinder, Model 4455677 Type 0827 E1, Code 0708 10YG. About 570 accumulated operating hours.
Started barely running-- took to independent shop. Said "bent" pushrods. Replaced them. Ran for less than an hour and same problem. He repaired it again. Ran for about 5 hours and same problem--but worse. So I now know that this fellow needs some help.
Researched the problem on YouTube and with Google. Google found this forum.
Mention of Walt Conner having developed a fix involving machining. Could not find details-- none of the links or email addresses worked.
Now am convinced that the problem is loose valve guide(s).
Could someone please direct me to details of the fix devised by Mr. Conner and any other durable repairs of which you are aware?
Has Briggs made effective changes to the newest replacement cylinder heads?
Your help is very much appreciated.

Bad valve would be my guess, unless they are really poorly adjusted... Check and see if the valves have full range of motion.

 

[Walt 2002]

Do not understand why addresses furnished did not work. Because of "Crawlers" harvesting email addresses I use system below. Put in proper format and remind me what you want. And yes, you need to steer clear of that repair shop. First thing you need to do is find out WHY the valve guides slipped. Most common cause is a cooling problem, plugged cooling shroud or cooling fins. Don't overlook passage running thru head around valve guide castings. Problem is not bad valve.

Walt Conner
wconner5 at frontier dot com

 

[callwill]

I bought a used craftsman with that motor. Second season of use I had a pushrod drop, get sucked in and it came back out in the other head!
It was a bit bent but it was there...2+seasons of mowing later i am still mowing with it after fixing the pressed in valve guide in the head while still on the motor. The guide had backed it self out of the head, so the pushrod bent when it could not open the valve like it should. I saw a utube video where the guy took the valve spring out, cleaned the guide where it presses in the the head, painted on red locktite and using a properly sized socket and hammer, tapped that guide back into the head. Then he used a drift to stoke(?) the guide/help pin it into place. That is what i did. New pushrods and adjustment and i am still happily mowing.

 

[TobyU]

I bought a used craftsman with that motor. Second season of use I had a pushrod drop, get sucked in and it came back out in the other head!
It was a bit bent but it was there...2+seasons of mowing later i am still mowing with it after fixing the pressed in valve guide in the head while still on the motor. The guide had backed it self out of the head, so the pushrod bent when it could not open the valve like it should. I saw a utube video where the guy took the valve spring out, cleaned the guide where it presses in the the head, painted on red locktite and using a properly sized socket and hammer, tapped that guide back into the head. Then he used a drift to stoke(?) the guide/help pin it into place. That is what i did. New pushrods and adjustment and i am still happily mowing.

That's what you do! Almost everytime a push rod is bent on one of these it is due to a slipped valve guide.
Putting new pushrod without fixing problem is a joke.
Don't wast money on new head....that's the "proper" fix at a shop and don't pull the head off to fix.
You only need to pull the head when a valve SEAT pops on ohv.
I did two kawasakis and a briggs twin last month.

Clean the guide well with carb or brake cleaner but you SHOULD cut a groove into it. I use a Dremel tool with a thin cutoff disk.
You have to position the groove where it will be just a bit below the top of the head area it drives into after you tap the guide back into head. I use red Loctite too and after it's in place you stake the aluminum toward the middle-toward the valve stem. This groove gives a place for the aluminum to get pressed into as you stake it and make a land to hold it much better than just pressure alone.
You want it deeper than just catching finger nail on it but don't cut halfway through the guide or anything crazy.

Then make sure the had is absolutely clean. HEAT it what causes this!!

Grass, or nests, or oily grime buildup. It is usually the one on the right if you are facing the mower.
Blow it off with strong blowgun or use engine degreaser and water hose.

You can often get by with out the groove but it make for a longer lasting - probably better than factory repair.

ALSO, many people make a bad mistake when mowing that can cause this.
They get done cutting for an hour plus then they turn off the blades and LOWER the engine speed...then ride it back to barn, shed, garage.
NEVER do this.
There are those that will say they have always done this and do problems...well.....not yet....and your head cooling fins are probably clean...let them get dirty and this will be the straw that breaks the camel's back.
The engine speed if roughly 1/3 at slow vs fast and cooling is less than 1/3.
The temp spikes many degrees for engine AND hydro trans as they have a 7 inch fan on top to cool them.

IF mower is cutting or moving....FULL speed all the time.

If you want to slow it down a few seconds before you shut it off, that is not a problem but no riding it at less than full speed after it is up to temp.

 

[Bus Driver]

The suggestion about an after-use cool down is really good. Some of the turbo Diesels require a cool down after hard running. Mr. Conner sent me his information and I am deciding which suggested fix best fits my facilities and "talents". Thanks for his generosity for that information.

Is the "slipped guide" limited to just the exhaust? Has anyone experienced that with the intake guide?

My search before posting here found one case where the guide moved toward the valve head.
Staking in the groove should handle both directions whereas welding limits movement in only one direction. If the guide moves toward the valve head, the valve stem will prevent the guide from becoming free in the engine port

 

[TobyU]

The suggestion about an after-use cool down is really good. Some of the turbo Diesels require a cool down after hard running. Mr. Conner sent me his information and I am deciding which suggested fix best fits my facilities and "talents". Thanks for his generosity for that information.

Is the "slipped guide" limited to just the exhaust? Has anyone experienced that with the intake guide?

My search before posting here found one case where the guide moved toward the valve head.
Staking in the groove should handle both directions whereas welding limits movement in only one direction. If the guide moves toward the valve head, the valve stem will prevent the guide from becoming free in the engine port

Nobody welds them as you're talkin two dissimilar Metals anyways. You're not supposed to weld aluminum to a hardened steel guide.
Don't worry about it moving in towards the valve head as this just really never happens. Small air cooled engines slip valve guides all the time and it is almost always out toward the rocker arm. I do so many a year that I lose track.
This is the Quick Fix anyways and it's usually a very good fix if not better than putting a new head on. If you go buy a new head the way the manufacturer wants you to do your ending up with one that wasn't any better than the first one you had that has already slipped. Of course as I mentioned it all comes down to if you keep it cool enough it probably won't slip anyways.
I fix these all the time this way because it keeps me from having to remove the head. You could take the head off and take to a cylinder head machine shop. You could even drill and pin or screw through the aluminum boss and into the valve guide which is how some machine shops would permanently and 100% fix something like this but this is really Overkill and not necessary especially considering they're going to charge you money to do this. I've never had one slip that I have fixed.

Don't overthink it and put too much time or expense into it. These are cool mower engines are low performance little turds. They have very loose sloppy tolerances and they're not putting out much horsepower at all for there size of combustion Chambers. They are actually a joke. A 597 CC twin engine available right now which is current technology has 22 to 24 horsepower. A 1988 Japanese ninja sport bike had 550 cubic inches and put out between 85 and 100. And those numbers went way up very quickly. Lawn mowers are turds but one advantage is they are very forgiving.

 

[Bus Driver]

"Nobody welds them as you're talking two dissimilar Metals anyways. You're not supposed to weld aluminum to a hardened steel guide."

The concept is that a small, short weld bead is on the valve guide only-- no attempt to bond it to aluminum and no weld into the bore of the valve guide. The bead serves as a lip or shoulder on the guide that lodges on the aluminum and prevents the guide from moving further into the hole in the aluminum. A foolproof and absolutely certain method of preventing the guide from moving further toward the valve spring side of the head.

 

[TobyU]

"Nobody welds them as you're talking two dissimilar Metals anyways. You're not supposed to weld aluminum to a hardened steel guide."

The concept is that a small, short weld bead is on the valve guide only-- no attempt to bond it to aluminum and no weld into the bore of the valve guide. The bead serves as a lip or shoulder on the guide that lodges on the aluminum and prevents the guide from moving further into the hole in the aluminum. A foolproof and absolutely certain method of preventing the guide from moving further toward the valve spring side of the head.

You could weld a little bit on each side in Theory but no machine shop wants to mess around in that small hole trying to weld under the valve head especially and no machine shop really wants to work on lawn mower heads anyways. Most have no desire to even mess with these things but they will from time to time. It's just way over till and not worth going that extreme. Like I mentioned the more extreme repair as opposed to welding is to drill and pin or drill and screw. That's a method that has been used over the years but not necessarily for lawn mowers because it's just not necessary for these applications. In cars or higher performance engines where they continually have problems some things have been used with positive results over the years. It would be like taking your lawn mower head to machine shop to get it milled flat when you're replacing the head gasket because you're worried about it being absolutely flat. This would be a waste of money. I'm sure there are a few people out there that do it but once again it is a waste of their time and money. No lawn mower out there that's being used to cut grass needs the head cut on a Surface cut machine. Warping is not really the issue. The poor quality gasket coming apart, degrading and blowing out is.
It's always good to think out-of-the-box and come up with alternative ways of fixing things but in this case it's not really necessary. Plenty of people get by with simply driving the valve guide back in and doing nothing else but possibly they have cleaned off the head or the fins some and it never happens again. I would not personally feel comfortable with that. Some people also pop valve seats back into place and do nothing else and have good results too. I wouldn't be so lucky. The most important thing is staking around the outside so you put some holding pressure on it but cutting the groove even just a slight one gives it a great deal more holding power.
I also clean it and use red Loctite however most people don't go the Loctite route and I can't tell you for certain if it does any good at all at the temperature is it exposed to but I have the tube here and it makes me feel better.
You would have to pull the head to weld both sides and my main goal on this type of repair is not having to remove the head. I can pull the valve cover off and feed some rope into the cylinder to keep the valve pushed closed, pop off the retainer and spring, cut the groove, clean and Loctite it, drive it back in and assemble spring, set both valves while I'm in there and button up the valve cover all in less than 30 minutes.
I have about 40 of them here at any given time to fix so time is of the essence.
Some shops won't even repair them this way. They simply will only do a new head. I always tell the customer that the manufacturer recommends a new head because they want to sell parts but that head is not new and improved over the one that failed to start with. This is the old school experience tinkerer method I always tell them which is true that I've never had one fail once I've done it.
I don't feel this is a cobbled repair or any way inferior and I have done it on my own machines on any that needed it. You have to balance quality cost and time. Some guys out there even in shops especially small ones are just hacks and will fix stuff that there's no way it's going to last the whole season or long-term.
This is not one that I have any concern of not being a quality repair. I did have one machine come back to me last season that was a commercial Scag 54 or 60 inch cut with separate pumps and wheel Motors and a Kawasaki 24 I believe. The machine was only five or six years old but looked like it was 30. I think the guy cuts a big field and uses it as a brush hog when the grass is way overgrown. He had a slipped valve guide on the exhaust valve on 1 cylinder and bent a pushrod. I fix this one and it was running perfectly and I told him to make sure he keeps the RPMs at full speed and never slows it down as that will overheat it. About nine months later he had the problem again and I was concerned that the repair might have failed. When he brought it to me the one I repaired was just perfect but the other valve look like it had moved just a little bit on the guide. It wasn't pressed all the way out like the previous one was or like most are but it did have one bent push rod. When I put the valve and it's fully open position to compress the spring I had a little but very little extra room to push down with my thumb until it bottomed out completely unlike the other three valves in the engine. So I repaired this one and replaced a bent pushrod and have not heard back from him.
When he picked it up and I told him that it was the other one on the same head we had fixed and the only thing that causes that is overheating and he repeated back to me and that I had told him do not slow the engine down once it was hot. I kind of found it odd that he said that and I'm kind of thinking that he was still going back to his old habits of turning off the blades and lowering the speed to drive it back to his barn and it finally clicked in his head that I said that could be the cause of his problems. So maybe he stopped doing that.

 

[Bus Driver]

Before posting about this problem, I did a reasonably exhaustive search on YouTube seeking posts by others regarding their experiences and "fixes" for this problem. One of those videos demonstrated his welding of the valve guide. My presently limited agility will not permit me to use the exact technique used in the video. But it was very helpful in helping me to develop the technique that I will soon try.

 

[Bus Driver]

My engine is 445677 Type 0827 E1. Thus far I have not found that the valve guide is available as a separate repair part for this engine. We know that it is steel. Some Briggs engines used brass valve guides- but not mine. Probably those engines were the old cast iron blocks. And MIG welding for brass is probably not possible- certainly not for me.

 

[TobyU]

My engine is 445677 Type 0827 E1. Thus far I have not found that the valve guide is available as a separate repair part for this engine. We know that it is steel. Some Briggs engines used brass valve guides- but not mine. Probably those engines were the old cast iron blocks. And MIG welding for brass is probably not possible- certainly not for me.

Years ago they sold oversized guides but they don't want you to fix. They want you to buy a new head!
No 31 series that I have ever seen used brass.

 

[TobyU]

Before posting about this problem, I did a reasonably exhaustive search on YouTube seeking posts by others regarding their experiences and "fixes" for this problem. One of those videos demonstrated his welding of the valve guide. My presently limited agility will not permit me to use the exact technique used in the video. But it was very helpful in helping me to develop the technique that I will soon try.

I blast Youtube almost every day. Almost all vids either do things the hard way or the wrong way.

SO many customers cause themselves more headache and expense tearing everything apart like most vids do.

So many engineers go about things "their" way or what they have decided should be better and make it not as good or just waste a lot of time and some extra money.
The guys who have been doing this for decades and seen what works and what doesn't are the best resource. Much better than a tech at a local shop even.
Walt Conner on here is an old school absolute GENIUS. He has forgotten more about mowers than most will ever know and I MEAN this literally!!
(unless he still remembers everything) lol

Different old school guys sometimes have different ways to accomplish the same end result and they shoudln't be saying the other is wrong or even better....just preferred by them.

Simply no reason to bother to weld the guide at all.
If you clean the fins off and run it at full running rpms once it is hot....you could probably just tap in back down and never have a problem, but if you stake it or groove then stake it and loctite, good betting money is on it never failing again.
Perfectly great repair in 1/3 the time or less than doing it some "other" way they might be better. Will be something else next time anyway. You will never have bulletproof or 100% on one of these engines.
If you fix one thing 100% break proof, the next will be a valve seat popping out, or it will have a valve stick in the guide a little and bend the weak aluminum intake pushrod. Or the ACR will break...but don't get me started bashing briggs for not fixing this way to common problem.
The the head gasket will blow and continue to blow as you accumulate hours and heat cycles. Bad design with too few bolts.
They are not life dependent aircraft or ultralight engine....thank goodness!!
Little turds they are but they get the job done quite decently and are cheap and easy to fix the times they do need attention.

 

[Bus Driver]

Given that the shop I used has proven to be unreliable-- and that my time to work on it myself is very limited, wife told me to just go buy new one-- so I did. Might post about that in another thread. Not too happy with it at this point.
Did get to work on this one a few minutes yesterday.
Sitting in the seat, the cylinder on the left had the exhaust valve pushrod laying loose, slightly bent, with the intake pushrod and rocker arm being OK. I removed the spark plug since that cylinder is not functioning normally without the exhaust and it runs some better-- enough so to be able to drive it with just one cylinder for loading with ramps onto my truck if necessary. The exhaust valve is very obviously protruding up into the valve spring.
The fellow mentioned earlier charged me both times for two new pushrods-- and I wondered if both intake and exhaust guides moved out simultaneously. That would be quite a coincidence. So now I think he just gouged me-- and is more skilled at gouging than at engine repair.
When time permits, I will remove the head and decide exactly what is next.

 

[TobyU]

It's really a fairly easy fix. The valve adjustment is the hardest part when you're done. Do not pull the head off. That is not necessary. You might even get by by just cleaning off the valve guide putting Loctite on it and driving it back into place. Look at the other ones on the other side and don't drive it in too far. It's supposed to stick out about an eighth to 3/16 of an inch. The intake one usually has a stem seal cap on it anyways.
If you have a Dremel tool get the thin cut off wheel and that way you can put a slight Groove around at that will be right below the aluminum level when you drive it back into place. But the most important part is to clean it well with brake cleaner or carb cleaner, Loctite it, and then once it's driven into place I use a deep well socket approximately the same diameter so you can leave the entire valve in place and the head on the machine, then you need to go around with a punch, I use a square number one or number two bitand stake it in multiple spots around the outside to push the aluminum tight against the guide.
It always seems to be that cylinder. That one's usually also a lot dirtier. So make sure you pull the Shroud and blow all the debris off and if it's very grimy use engine Degreaser or simple green or super clean and soak it and blast it off with strong water hose pressure. Just block off your intake so you don't spray water down to the throat of the carb.

The hardest part is probably getting the valve keeper retainers back in. You either need to use air pressure from a special adapter at about 15-20 PSI to blow into the spark plug hole to keep the valve shut but that's a little more complicated, or lower the Piston down to about halfway and feed three or four feet of rope about the size of starter pull rope or even a little bigger into the spark plug hole. Then slowly turn the engine by hand until the Piston presses the Rope tight against the valves to hold them shut. Sometimes you have to work it around just a hair to get it to hold the valves tight. Then you can push the Springs down with your thumb and pop the retainers out and the keepers but putting them back on is a little trickier. You have to make sure you put them in with the angle going the right way there they fall out many times as you try to do it. I have found that a pair of needle-nose vice grips small or medium-sized adjusted so they're just wider than the valve stem itself makes it pretty easy to push the retainer down and compress the spring while you stick one keeper in and then the other.
It can all be done in less than an hour and head is always been a permanent fix for me. I feel that the repair is almost always stronger than the original head the way it came from the factory.

 

[TobyU]

I don't think he was gouging ou for the extra push rod as most of the time they are both bent.
The aluminum one is so weak that when the exhaust valve cannot open to let the exhaust out and after the combustion has occurred the Piston is trying to come up against compression that's not supposed to be there and the intake valve is trying to open but the piston and pressure is trying to force it shut so it bends that valve even though that guide is perfect. I see both pushrods bent all the time or I see an intake push rod bent on a Briggs single where the exhaust valve rocker arm stud simply loosened up. The exhaust push rod is just fine since its steel but the intake valve pushrod which had no valve train problems whatsoever is bent because the pressure of the engine trying to run forced or kept the valve shut when it was trying to be opened so the pushrod bends.

What I do think is he's not that well schooled or knowledgeable in knowing why he found bent pushrods. Very, very rarely when you find a bent pushrod can you simply replace it and not end up quickly with another bent pushrod. They don't bend on their own. I have seen a few we're completely through and bend and actually break right where they rub against the plastic guide underneath the rocker arm studs. It amazes me that a black plastic guide can wear through an aluminum push rod. But I've seen it three times.

 

[Bus Driver]

For the 2-Cylinder Briggs engines, the cylinder heads are one each, Right and Left. Mirror opposites. The parts lists do not help me to know which part number is the Right or the Left.
From Internet searches, the head numbers for my engine appear to be #796231 and #796232. Possibly the #796232 is the one on the Left when seated on the mower in the driving position-- the side with the fuel pump mounted near the head. Can anyone confirm?
With the rocker arm cover removed, numbers are visible inside the rocker chamber. These probably just identify the number of the mold used to make the casting-- the molds would have multiple cavities to make several parts in just one operation-- thus those numbers would have no meaning outside the manufacturing plant.

This video illustrates the technique that I believe others on this forum prefer.

 

[TobyU]

The numbers inside don't matter. The numbers from the engine are all that matter. The number are stamped on one of the rocker arm covers. It doesn't really matter because all 44 series heads will interchange.

 

[TobyU]

And never, never ever ever, buy a new head. You're ending up with the same junk that failed you in the first place.
You really never need to replace a head unless you find one with an extensive crack. If you have one that has to be replaced and simply get a used one off of another engine from eBay or swing by a local small engine shop and buy one out of their junk parts. Popped out valve c or slipped valve guide is an easy fix that cost zero money. A new head is like $150 plus. You would be better off to take your head to a machine shop and let them fix things which would result in a better quality head than a brand new one.

 

[RoyM]

The heads are offset on the block. #1 is p/n 796231 and closest to the flywheel.