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Briggs 446777 Engine, Low Oil Shut Off

uglyblue66

Subscriber
Last Subscription Date
11/07/2018
Well I guess today it was my turn in the barrel of shi- happens .
I bought a Everride zero turn mower in april of 2006 and it has 264 hours on it. 25 hp briggs 2 cylinder engine.
I bought a good mower and have kept it's oil changed and so forth because I wanted it to last a long time. For 5500 bucks it should.
But I was mowing today and all was well until I turned left kinda sharp and started up a little grade along the roadside that I keep mowed in front of the house. There was a sudden noise,a grinding sound like gears grinding,then the engine started missing and rpms reduced. I idled it into the shop and I thought it had swallowed a pushrod like my neighbors engine did like this. I pulled 1 spark plug wire and it cut off, pulled the other and it stayed running. But there is a noise in there and it don't turn over right. It was a little low on oil and it is black as a cast iron pot and I know I changed it not 2 months ago ,less than 5 hours of operation.
I am trying to figure out what went wrong. It would seem if it was oil related the pressure switch would have cut the engine off before anything happened would it not?
In short, I will have to tear the engine down and see what happened but anything I can learn before hand will be handy info.
This really bugs me as I had plenty enough to try to patch up around here with out my zero turn machine flying to hell.:rant:
 

Tracy T

Subscriber
Last Subscription Date
07/16/2019
Re: Briggs 446777 engine,low oil shut off. :(

I am not familiar with your specific engine but I will give you a couple pointers, neighbours Kohler took a crap similar to what you described it was a twin cam engine and one of the camshaft's broke. Briggs use to have a screwy counterbalance that would come apart. Post up some pictures of the carnage when you can. Inquiring minds want to know!
 

Vanman

Subscriber
Last Subscription Date
07/10/2019
Re: Briggs 446777 engine,low oil shut off. :(

Black oil that isn't old makes me think that it got HOT. Then the oil breaks down, loosing it's lubricating ability and... Bad noises and bad things.

Are all of the cooling air passages clear of debris?
 

Tracy T

Subscriber
Last Subscription Date
07/16/2019
Re: Briggs 446777 engine,low oil shut off. :(

Black oil that isn't old makes me think that it got HOT. Then the oil breaks down, loosing it's lubricating ability and... Bad noises and bad things.

Are all of the cooling air passages clear of debris?
X2! Another neighbour with a Briggs had what he thought was serious problems, damn mice packed it full!
 

uglyblue66

Subscriber
Last Subscription Date
11/07/2018
I had the shroud off in july because I cleaned the carb.It had been sputtering and i thought it may have water in it. so I checked the cooling areas and dust,but no accumulations that should interfere with cooling.
I have the shroud off now because I thought perhaps the plastic fan blades had busted and were tossing around in the shroud. I found that on a John Deere back in May. Rust had pushed the plastic up from the flywheel enough it caused impact.
But no problem of that type here.
I use Havoline 10-30 and Microgard oil filter made by Wix. So I didn't use wally world special.

I find alot of mice compactions in machines I work on for other folks but thankfully this 1 is not 1 of them.
 

Brian Lynch

Subscriber
Last Subscription Date
07/13/2019
Check the valve guides on the affected cylinder. They will loosen up when the engine gets too hot and will migrate. If you find bent pushrods it went out towards the rockers. A valve stuck open or not seating properly means it went towards the valve head.
 

uglyblue66

Subscriber
Last Subscription Date
11/07/2018
Well,it destroyed a connecting rod!
Here is a pic of the engine as it looked when I removed the shroud.
Also is a pic of the rod!
The piston is also damaged.
BUT the good news is, the aluminum flaked right off the crankshaft and it polished up nice,no damage. No damage to gears,cylinder,top or bottom bushings,nothing. Just the rod,and boy did it come apart.
There was a good bit of oil in the engine.And when I removed the oil pressure switch oil squirted out of the hole as if it had pressure on the switch and it has not been run since Wednesday.?:shrug:
Any how,gota started doing a parts search and then get some funds in the ebay account monday to buy parts.
it coulda been worse.

I am going to get 2 new pistons,rods,rings,oil seals,gasket set. That should cover it.and of course give the cylinders a good honing.
 

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Tracy T

Subscriber
Last Subscription Date
07/16/2019
Looks designed to fail after x number of hours. Glad you have enough left to work with though, most folks would junk it and buy another.
 

sprkplug

Subscriber
Last Subscription Date
02/17/2020
Looks designed to fail after x number of hours. Glad you have enough left to work with though, most folks would junk it and buy another.
Would you mind pointing out from the photos just what you see that was " designed to fail???" That's a load of BS

Unless you're mowing grass in January, you need straight 30 in your Briggs. I won't say that is the reason the rod broke, but it's good practice nonetheless. Metal transfer to the crank, along with black deposits usually indicates lack of oil. Maybe it was too low, maybe the pump failed, maybe a combination of low oil and the slope proved fatal. Did you check the oil before you started mowing?

Also, the oil pressure switch might just turn a light on.....NOT shut the engine down.
 

uglyblue66

Subscriber
Last Subscription Date
11/07/2018
Yea I did check the oil, where the E@#* it went? only other thing maby the machine was not level as it needed to be.


How could I tell if the oil pump failed?
There is no light on this machine. I have 1 with a light on a vangaurd but this 1 does not.

Very confusing on the oil. help me out here,
Book here from Everide says 10-30 10-40 all across the chart, 30 weight also from 40 to 100 Degrees ambient temp?
I do know this,I will be going back to Castrol for better heat protection.
 

Tracy T

Subscriber
Last Subscription Date
07/16/2019
Would you mind pointing out from the photos just what you see that was " designed to fail???" That's a load of BS
Load of BS you say, that rod broke in two different places top and bottom. Fatigue is what wiped it out, no warning no low oil pressure it simply broke! I have seen small air cooled engines run out of oil until they seized up and not a one of them broke the connecting rod. Mr plug you tend to argue in almost every post that I have ran across, so I am sorry if you disagree with my thought on the matter.:salute:
 

gdstew

Registered
I was in the small engine business as a B & S service distributor for over 45 years. That rod broke due to insuffient lubrication. I have seen 100s of them. A clean shattered rod would be overspeed, a melted rod is oil. It might of had oil but not enough or the right kind. Just lucky it didn't blow a hole in the side of the block, and take the camshaft too!

Above 40 degrees use nothing but #30 high detergent oil. Winter ( snow blower, log splitter, etc ) use 10W-30. B & S just in the last several years approved 10W-30 synthetic for year round. We saw lots of the older twins, either blown up or the valve seat popped out, every one was using multi viscosity oil.
 

sprkplug

Subscriber
Last Subscription Date
02/17/2020
Tracy T, the proof is in the photos and the description: metal transfer from the rod to the crank. If there had been a design failure like what you claim, the bearing surface would still be shiny....not smeared due to no lubrication.

I was a Briggs and Stratton master service tech, certified expert status by Kohler, and ran my own repair business for years. That engine failed because of lack of lubrication. Period.

Blue, its about temperature. Always use the heavier oil for the temperature range you will be using the engine in.

The internet has given rise to armchair experts, folks who are honestly trying to help, and to a much lesser degree, those who actually know a thing or two. Unfortunately, we're all given equal room to say our piece. Same old thing, eh Gary?:)
 
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uglyblue66

Subscriber
Last Subscription Date
11/07/2018
Well the main thing is I want to prevent this happening again.
How can I determine if the oil pump was functioning? If it was by remote chance a bad filter, that will obviously be fixed when a new 1 is put on.

I will go back to castrol and use the 30 weight. I just remember when the overhead valve engines came out they said they needed the multi weight oil and since the chart showed it I thought I was in the clear. OH well so much for the book!
And as for designed failure.I am thankful the replaceable rods did give up the ghost and not something more expensive. I can repair and move on.

I am going to look at that wiring for that oil pressure switch, I just cant help but think that should a protected the engine.

well I looked up parts and I think these 3 listings will cover what I need.Looks to be a little under 180 for the parts. Then there is oil and filters as i want to change break in oil after a couple hours running.

https://www.ebay.com/p/Engine-Gasket-Set-for-Briggs-Stratton-694012-Replaces-499889-Fast-Ship/623788893?iid=252781862219&_trkparms=aid=222007&algo=SIM.MBE&ao=2&asc=47507&meid=b4771df9a73947db97406dd68d460d8f&pid=100005&rk=1&rkt=6&sd=232267225799&_trksid=p2047675.c100005.m1851

http://www.ebay.com/itm/Briggs-Stratton-796209-Connecting-Rod-Replaces-699699-/321118244565?epid=2255520819&hash=item4ac4238ed5:g:N6oAAOSwnONZCixg

https://www.ebay.com/p/Briggs-Stratton-24hp-Twin-446777-Piston-Pair-of-Pistons-792023/1409877679?iid=263198825026&_trkparms=aid=555018&algo=PL.SIM&ao=2&asc=47507&meid=6c5d6c33311e4b738304e58fa1c2e5ba&pid=100005&rk=2&rkt=4&sd=282607670910&_trksid=p2047675.c100005.m1851
 
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Vanman

Subscriber
Last Subscription Date
07/10/2019
Just as an aside, 10w-30 oil IS 30w once it's warm. I still bet on thermal breakdown.

I'll have to check what I use, but I believe that it is a Castrol 5w-30. One of the reasons was that it ranked highly in the thermal breakdown category. The other was the high film strength rating.

And affordable and readily available at Walmart. :brows:
 

K-Tron

Registered
How does the other rod look? I would definitely remove the other rod, and at the very least torque the cap back on and measure the bore. Now that you have the engine apart, spend the time to remove the crank, set it up on v blocks and check all critical surfaces with a micrometer. Pipe cleaners of various size work well to clean the oil passageways. Perhaps one of the oil passageways was clogged? Testing the oil pump, or replacing it would be a good idea; Briggs parts are rather cheap and readily available.

Chris
 

gdstew

Registered
American engines used #30 oil for the last 60 ? years. Even the old OH Tecumsehs used straight oil in the summertime. It wasn't until Kohler came out with their overhead Command series that they recommended 10W-30 oil because they had hydraulic lifters. The straight #30 was based on the high heat of an air cooled engine. The multi viscosity oils such as 10W-30 is a 10 weight oil that heats up to a 30 weight but usually takes close to a 1/2 hour to do so. Then SOME of those oils are not good enough for the extra heat and they break back down. B & S never recommended multi viscosity in their overhead engine but did say that 10W-30 synthetic was an acceptable substitute.

The Hondas and Kawasakis have had different oil recommendations but that's a different discussion.
 

Bill Sherlock

Subscriber
Age
75
Last Subscription Date
07/09/2019
I have used nothing but DMO #30, a heavy duty diesel motor oil in all my air cooled engines for the last 20 years or more and haven't had one fail yet. Only exception is for my snowblower, use DMO 0W40 in that because of the sub zero temperatures we get here during winter. I would not use a multigrade oil in an air cooled engine for summer use no matter what was in the manual.

Bill
 

sprkplug

Subscriber
Last Subscription Date
02/17/2020
Also remember that a low oil level shut-off is an entirely different animal from a low oil pressure shut-off. The low oil shutoff will kill the ignition, but the low pressure switch usually just turns on a light. There are systems that use a module or relay wired in to the ignition circuit along with the pressure switch, but they require a means to bypass while starting....otherwise you would crank forever trying to build enough pressure to allow the ignition to produce a spark.
 

Tracy T

Subscriber
Last Subscription Date
07/16/2019
Mr plug I am too tired at this point to debate this any longer today, but I ask you this. If it was a oil pressure or lack of oil, why did the other rod not suffer from the same?
 
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