one possibility is a stucking intake valve - due to fuel varnish or old fuel. The push rod may bend or fall out of position when a valve sticks. If the valve is in the closed position, a compression test would indicate compression - giving you the impression valves are working.

Remove the valve cover on the dead cylinder for examination. If you find the push rod out of position, a gummed up valve is a likely cause. Some shops perform quick fixes by spraying carburetor cleaner on the valve stem. The best fix is to remove the cylinder head. Remove the valve to clean the entire valve quide and valve stem. This problem can occur on any brand engine.

Good advice from larryf. I've had a Briggs 5-hp single lose the keeper off a valve stem, and a Tecumseh 12-hp single bend/break a rocker arm. No apparent reason for either, but replaced the keeper and lifter and no more problems.

Bill

Okay. Got the Briggs model number off the engine.
Model 446777 Type 0177 E1

I removed dead cylinder valve cover and noticed right away the intake (bottom) rocker arm was free. Looked around at the base and found a nicely curved push rod. Bummer.. Looked at the exhaust valve push rod and it is slightly bent but still in place. Pulled off the other valve cover and checked those push rods and they seem straight. Rocker arms had a fair amount of play in both. On the dead cylinder both intake and exhaust value springs look alright and I can manually open the values. Should I just replace the push rods and give it a try or should I probe further ?

Thanks,
Tom :)

Well you didn't post the rest of the numbers so can't tell how old the engines is but I would check the head carefully for valve guides slipping up, loose rocker arm studs, cracked rocker arms. Something caused this.

Another person recently got a new head and replaced at no cost even though his engine was out of warranty when there was a problem with a head.

Walt Conner

Hi Walt,
The full numbers off the valve cover are
Model: 446777
Type: 0177 E1
Date Code: C20726YG
On the date code the first letter C could be an incomplete O
but it looks a lot like the C in the Code stamp.

I did move the valves again by hand and noticed the top on does have a slight catch or rough spot about 1/2 way in. As I understand it one push rod is steel (bottom valve) and the other is aluminum (top valve). Why ? I am guessing the aluminum one is suppose to fail as a safety. Both are bent. Seems like a backfire would not do this damage. I suppose it is time to remove the head and see what additional damage has happened.

Thanks,
Tom :)

I would do a search of this site for similar problems. As I said, someone else got a free head and installed even though the engine was out of warranty. I am sure your code number is 02 meaning 2002. The post I am referring to had the contact at B&S. Sounds like your valve stems are bent also. Some of this series of engine seems to have a problem with one specific side.

Walt Conner

Hi Walt,
I was unable to find the referenced posted. I did get some time to tear apart the engine this weekend. Really easy. Remove six engine engine cover bolts. Remove four bolts for fuel pump assembly. Remove four bolts for valve cover. Remove five bolts for cylinder head. Half hour tops as I was going slow being first time I did one of these. The piston is carboned up but in good shape. The valves are straight, seal good and only have a little carbon on surface. The rocker arms are not cracked or bent. It appears the only things that are wrong are the push rods for the valves being bent and the head gasket. The head gasket had blown one layer off (so it was half thickness for about a 3/8 inch width) on the exhaust side so it was venting (and sucking) just next to the exhaust pipe. I can see if it had blown the gasket right next to the push rod chamber it could suck in a lot of oil. I suspect this is where people are getting reports of large consumption of oil in these Briggs engines while running. Looking at the design there is not much area (beef) between the piston and the push rod sump area so a good backfire could easily break the gasket in this area. Backfires are easy to achieve just by bouncing on the seat going over rough terrain while the engine is at high RPM. It is basically turning off the engine then back on. I know I have done this in a couple of rough areas on our 2 acres.
The gasket for my 26HP is only $ 6.00 and the push rods around $ 5.00 each. The valve cover gasket another $ 5.00. So for $ 25.00 it looks like I can bring it back to life. The downside is that I do not have a in/lb torque wrench so that will be another tool to add to the collection but something that I think will be used a few times with this engine design.

My father in-law has a 24hp Briggs Intek that burns a pint + an hour so I think I can fix it for him after seeing the design and what probably failed..

Do you know the bolt tightening pattern and the torque setting ? I think it is 220 in/lb for the head but want confirmation. Also is the valve to push rod clearance values ?

Thanks
Tom

Help...
Finally got the gasket, pushrods and a bit of time. Cleaned and assembled the head with no problem. Made sure both spark plugs removed then inserted the pushrods. Aluminum one on top (intake). Start turning the engine by hand to adjust the valves. Top valve clearance okay. Inserted steel pushrod on bottom (exhaust). Bottom pushrod valve clearance okay. Started turning a little more and then meet with resistance as exhaust valve opened all the way and then the new steel push rod bent. What the heck.. Pulled out rod and straighten. Put back. repeated process. The pushrod pushes the valve more than it will go then meets with resistance then bends. Pushing the valves in by hand they both go in the same distance. The other side does not seem to have this problem. Both go in the same amount on that side as well. I then backed out the adjuster till it would not bend but then there is 1/4 inch of play. If I adjust it for the correct clearance then it wants to bend the rod at top of exhaust stroke.
It is like the cam for that exhaust right port (right side if in driver seat) is not machined correctly. A bent cam. A defective cam. Is this possible ? What do I do next ???

Tom

Any chance you got the wrong push rod ... too long?

I actually thought about that at first then I checked the numbers. They are the correct numbers but I guess it could be incorrectly packaged. Still if the valve clearance is correct on the down side then it should be correct on the up side if the cam lope is machined correctly and the rocker arm the correct length. Another possibility is that I think I checked the valve when the piston was on the down stroke. If the valve is actually hitting the piston and not allowing it to open all the way I suppose that would cause it but I would think the other side would suffer the same problem. The piston did come out flush with the head on the up stroke. Not sure if that is correct. There was no evidence of the valve hitting the piston when I had it apart. Just a lot of carbon. Any more suggestions ?

Thanks,
Tom

Valve guide has moved out of position, limiting the travel of the valve. ???

Here's is a thread, which might help you out.

Here is a link that might be useful: Another Intek thread

"Valve guide has moved out of position, limiting the travel of the valve. ??? "

Possible I suppose. Tomorrow I will check all travel distances with calipers for both sides. I will get valve travel as well as pushrod travel. That should help to determine a possible direction to follow.

Thanks for the link. Looks like others with different B&S engines are having the same problem. I do remember noticing the valve guide was sticking a bit further out on the exhaust (bent pushrod one) than on the intake. Guess I will have to email Walt for the 'fix'

Thanks,
Tom

They used to change Harley valve guides regularly. Not because they moved, but due to wear or to upgrade. If all else fails, take it to the local Harley dealer and see what their guides look like and what the procedure is to change one, so it "stays put". ... just a thought.

Hi All,
Just talked to a nice Briggs tech who agreed to cover the cost of the part ($ 89.75) if I took it to a dealer and the dealer determined that the exhaust valve guide was indeed the problem. Of course I would have to pay the labor charge (???) and the dealer would have to fill out the paperwork for warranty even though the engine is past warranty. The Briggs guy said they would cover it even if it was past warranty. Hummm.. He basically admitted that there had been / was a problem with the guides coming out. I guess they are pressed fit and after getting hot then cold so many cycles they sometime come out. It seems my original part number for the number one cylinder of 697580 has been replaced with newer part number of 792299. He was not sure if the newer part number had an improved guide. I tried to get one just sent to me but they apparently had none in the tech stock to do that so the only other option is to get a dealer to do it from normal stock channels and do a warranty type repair. Somehow I think the labor cost will be about the same if I just ordered the part and put it in myself. bummer. Guess I will try to see if I can re-seat the original guide first and keep it in place before forking over 90 bucks.. Not happy with Briggs engines now..

Later,
Tom :)

I determined there is no such thing as a 'free' cylinder head.
I did remove my #1 cylinder head and confirmed that the exhaust valve guide was way out which was not allowing the exhaust valve to open all the way so the pushrod gets bent.
The pushrod may stay in place for a period of time and it still opens the valve somewhat. Eventually the rod falls out and the valve does not open at all. So what happens next. The exhaust has to go somewhere so it blows out the head gasket. Sometimes in a non-critical spot. Sometimes in a critical spot like the oiled valve guides which will then start the engine smoking. Briggs knows about this problem.
Briggs tech indicated that they would warranty out a new head even though engine was past warranty. I called the local authorized Briggs repair shop. Short version below.
-----------
Me: Hi. this is so and so that as been buying parts from you to fix my Briggs engine. (head gasket. Push rod. etc)

repair shop: Oh hi. How can we help.

Me: I removed my #1 cylinder and measured the valve guides. The exhaust valve guide is way out of the casting causing the valve not to open. I talked to Briggs tech support. They will cover the part even out of warranty. I got the techs number here so you can talk to him directly. I want to bring the head in so you can look at it to verify the guide is out so you can order me a replacement under warranty repair.

repair shop: You have to bring the whole mower in so we can check it.

Me: Well the mower is all apart in my shed. Besides I have no way to bring it in at the moment like a trailer or truck.

repair shop: Well we can come and get it but it has to be all back together.

Me: There is nothing wrong with the rest of the mower engine. It is this #1 cylinder head.

repair shop: It is Briggs rules. Sorry we have to follow the rules. Briggs tells us we have to look at all mating surfaces. When do you want us to pick it up.

Me: Is picking it up covered under warranty.

repair shop: No. we charge $ 45.00 to pick up.

Me: I see. How long will it take for repairs.

repair shop: Well we are pretty busy right now. A couple of weeks.

Me: Why do you need to look at the mating surfaces. I cleaned them all up. They look almost new.

repair shop: Sorry. Briggs rules state we have to look at the entire engine.

Me: Okay. Can you just send someone out just to look at it without hauling it back.

repair shop: Well we could but we would still have to charge a $ 45.00 service fee. We could not get someone out to look at it until next week. If he did determine it was the cylinder head then we would fill out the warranty papers to get the part. Might still be a couple of weeks.

Me: So I suppose the warranty does not cover the cost of hiring someone to mow my grass.

repair shop: Afraid not.

Me: Here is the part number for the head. 792299. How much and how long to get.

repair shop: Lets see... $ 89.75 and we can have it it two days.

Me: Okay. please order me one.

repair shop: Okay. one is on order. see you in two days.
------------------
My take on this. My time putting the engine back together which the repair shop will just take apart, cost of paying someone to mow our 1.5 acre yard twice and the cost of having the dealer bring in the mower is going to be a fair amount more than the $ 89.75 that I will have to spend to get the mower repaired in two days just for buying the part outright and doing it myself. So much for a 'free' cylinder head. Looks to me that Briggs looks good (Good PR) by offering to replace the head even past warranty but then have these 'rules' for the repair shop to make it a pain to collect. Of course the dealer is going to get blamed for all the hassle. All of this for an apparent defective head. I figured defective because Briggs superceded the old part # with this new part # so I figure they fixed the problem. Wonder why my view of Briggs went downhill..

Later,
Tom :)

Local Kubota, Scag and CC Dealer has this sign on wall above service counter.
Labor rates
$60.00 per Hr.
$70.00 per Hr. if you watch.
$80.00 per Hr. if you ask questions.
$90.00 per Hr. if you help.
$100.00 per Hr. if you start and ask us to finish.
They laugh and say we will repair your equipment if it breaks, we will train you to repair your equipment, we can also repair your mistakes.
They all have thier price.

LOL...

I bet my rate would be on the upper end.

I am not begrudging the repair shop. They have to make a living. I am just surprised that Briggs supposedly have these 'rules' so their offer of a 'free' head really turns out to be not so free if you really take into account all factors. I would be super happy with Briggs if all I had to was bring in my obviously bad head and the repair shop just gave me a replacement. Even if I had to bring in the valve cover with the model number as proof of engine ownership would be easier than hauling the whole tractor around. I suspect a lot of people like myself just cave in and buy the head just to get their machine running instead of dealing with the hassle factor. In the end Briggs looks good because they 'offered' a free replacement but in reality there are strings attached. It also saves them the embarrassment of issuing a recall. Oh well... life goes on...

Later,
Tom :)

Its not just briggs with requirements like that. I have a cub GT3235. I broke a bracket that holds the mower hieght knob. It was my fault. I can set my mower height either adjusting this knob or with the casters on my deck,not both. I did both. Anyway I went to the dealer to order the part. It was covered under my warrenty, but the shop had to fix it. There pick up rate was $45 and it would take about a month to get it into the shop. The part new was only $22 and would arrive two days later. I just bought it and put it in myself.

We had a guy call a couple of weeks ago, wanting me to give him a free coil for his Briggs Intek, under warranty.

He pulled off the plug wires on each side while it was running, and determined that one of the coils was bad, because the engine was only running on one side.
I told him I couldn't, because Briggs wouldn't pay the
warranty.
I also told him to remove the valve cover on that side............................

Just for giggles.

Or he could bring the mower in and Briggs would cover it

Fish

Any dealer who would tell a customer to remove a part "just for giggles" just lost my business. Forever.

Unless, of course, someone told me that employee is no longer working for that dealer.

Fish
Where is your shop?

Fish

I apologize for the inappropriate remarks above. You're right, of course. It was probably valve related. An appropriate quote:

"We are masters of the unsaid words,
but slaves of those we let slip out."
--Winston Churchill

Again, I apologize
Ted

I always wondered why I keep getting fired........

Hi All,
Got the new cylinder head. It does look like Briggs did something different with the valve guides. Not sure what. Anyway here are a few picture for those of you that keep getting bent pushrods or blown head gaskets which can cause nasty problems (oil consumption ?) . Maybe these pictures will help show you what might be causing the problem.

Picture #1 here is a close up shot of the #1 cylinder head exhaust port with a red text note of the position of the exhaust valve guide.

http://photos.gardenweb.com/garden/galleries/2007/10/bad_briggs_cylinder_head.html?cat=tractors_lawn_equipment

Picture #2 here is a close up shot of the #1 cylinder head exhaust port with a red text note of the position of the exhaust valve guide. This shot is about top of cylinder casting level with a couple of notes. Note the valve guide is about 1/8 to 1/4 inch above the cylinder head casting top. This causes the valve not to open completely. When the valve can not open completely then something has to give which is the push rod. Once the push rod bends it is more likely to fall out. When it falls out the valve will not open at all so when the #1 piston fires something has to give. That something is the head gasket. When the head gasket gives it has a pretty good chance of giving out at the section between the push rod sump and the piston. When this happens the cylinder will suck (and burn) a lot of oil.

http://photos.gardenweb.com/garden/galleries/2007/10/bad_briggs_cylinder_head_2.html?cat=tractors_lawn_equipment

Picture #3 here is a close up shot of a NEW #1 cylinder head exhaust port with a red text note of the position of the exhaust valve guide. Note that is that guide is where it is suppose to be which is really close to the entry point of the valve stem.

http://photos.gardenweb.com/garden/galleries/2007/10/new_briggs_cylinder_head_exhau.html?cat=tractors_lawn_equipment

And finally last picture is of the old and new cylinder heads. If you look closely you can see the difference in the height of the valve guides between the two heads.

http://photos.gardenweb.com/garden/galleries/2007/10/old_and_new_cylinder_head.html?cat=tractors_lawn_equipment

I am hoping that this will help people identify a possible problem with their engine.

Later,
Tom :)

Had this exact same problem with a 27hp Intek. Also didn't think that the "free" cylinder head was worth it, so attempted to fix the existing one. Took everything apart and tapped the valve guide back in place. Apparently the metal is very sensitive and tapping it in created burrs around the opening causing the valve to stick. I was able to clean it up and everything worked fine. However, when I put it back together, I can't get it to start. It cranks over, but won't start. If the choke is set, it backfires puffs of white smoke through the air intake. With the choke off, it just cranks with the starter but won't fire. I've checked everything I can think of. Timing marks are lined up, valve clearance is correct and flywheel key is not damaged. Can't figure out whats going on. Any thoughts? It's a Briggs and Stratton, 27hp Intek, model 446977, code 0471. Thanks.

Sorry, hadn't been following this thread. I told you quite aways back, and you mentioned it, that I had a tried and proven fix, no cost for the fix, just new gasket and push rod.

Walt Conner