Well IF I am seeing what you are talking about, I would say the sump gasket is leaking. The gasket between the bottom part of the engine crankcase and the upper part which contains the cylinders. The shiny metal thing with a screw in it is part of the cooling shroud and would have nothing to do with an oil leak.

You could TRY tightening the bolts holding the sump in place but doubt very much it will help. Almost always takes a new gasket IF that is the problem. I carefully torque these bolts to 225 inch lbs.

Walt Conner

thanks a bunch for the reply Walt.

i don't have a torque wrench but i will double check and make sure the bolts aren't obviously too loose.

is the sump the part with the fins?

i just got a reply on another forum from a guy who thinks it might be a cracked cylinder? is there anyway for me to check for a cracked cylinder?

it seems to drip oil even when it's not running as it's always wet in that same spot. the thing runs and sounds good and even starts up easily with the choke - and sometimes without.

on start up though it blows a big puff of white smoke and continues to until i push the choke lever back in and the smoke goes away.

any other ideas?

What Walt said. A cracked cylinder would be a very unusual problem.

thanks a bunch.

how hard is it to replace the gasket? is something someone who doesn't have a lot of experience with small engines could do with instructions or a repair manual?

i'm no mechanic but am handy with minor repairs. the biggest job i've done is replacing spark plugs in my truck.

here are a couple more pictures from beneath the mower and a wider shot of the side of the mower...

{{gwi:140545}}

{{gwi:140547}}

...the first is from beneath the mower right where it's leaking. The second pic has a little peice of (spray painted) sheet metal that seems to have been placed there to catch the oil so it doesn't run down on the deck/belts?

I should also add that the guy I bought the mower from is a seasoned small engine mechanic - enough so that he just replaced a transmission in an exmark zero turn. Yet he tells me he didn't know the mower had a leak even though it was pretty evident to me right away.

So, I'm worried that something serious is wrong with it otherwise it seems he would have fixed it if it were minor before listing it on ebay.

You are showing us two different areas of the engine. Is the oil leaking and running down then dripping from the area you are showing us now or is it leaking from different places? The Sump is the bottom part of the engine, what you might call the oil pan. Is the bottom seal leaking? The crankshaft at the bottom of the engine will be wet with oil if so and oil will be thrown outward.

Unfortunately, 20 B&S Flathead Engines are notorious for throwing rods. When they do, they pretty well wipe out the inside, cracking the block is not uncommon. It is possible but I for one, can not tell from here, the pictures are good but just not plain enough to tell such a thing. IF that would be the case, it probably is a small area and can be fixed by grinding the crack lightly and applying JB Weld.

IF it is the sump gasket, you MIGHT be able to replace it with a manual though I am not going to recommend it given your posts to present.

Walt Conner

the first pic of the two is beneath that homemade sheet metal shield he made - you can barely see the shield in the top right of the pic.

the other pic is of the shield - i just wanted to give more information about the mower so you all would know the whole story b/c it just seems that he would have fixed something minor.

how about this... if the mower does have a thrown rod or cracked cylinder, would it make any distinct noises or would it just run and start normally?

thanx some more Walt.

btw, the engine model number is #460777 - there are a couple other numbers on it if those would help i'll grab those to but the one above were the only ones under model#

IF there is a minor crack in the block, it will not affect the starting or running. It simply needs sealing to prevent leak.

I still lean towards a leaking gasket. I would think that by wiping the oil off you could tell if oil is coming from a joint, gasket area, or a crack in the block.

Another thing to check is the valve cover plates, the little retangular covers, one on each side, behind the Intake Manifold. There is a screw at each end, check for loose screw.

Walt Conner

hi again...

i ended up removing the head(?) and still can't tell where the

leak is coming from as i'm really not sure what to look for.

if i had to guess i'd say the bottom part looks oily like it's been leaking?

hopefully, these pics will be more help than i am at this point...

{{gwi:140548}}

{{gwi:140551}}

...also, is all the black stuff normal? it's thin, hard and flaking off like old paint.

i have a gasket for it and will put this on but would really like to hear from one of you guys before going any further just incase there's something more serious than a bad gasket that an untrained eye would miss.

okay, i put on the new head gasket and it's still leaking of course... ARRRGH!

i went back over the messages and can NOW see that you were talking about the SUMP GASKET right? if so please accept my apologies as i have spoken to so many people about this that i got confused.

at any rate, after the head gasket failed to fix anything i got further under the mower and think i have found where it is leaking...

{{gwi:140553}}

...the seam that runs along the side of the engine seems to be the culprit as i sat there and watched it after letting the mower run a while.

i couldn't tell 100% whether the oil was coming from this seam or somewhere higher then just collecting at this seam.

is the lower part of the engine in the red square the sump? thanks for your patience.

rtb

I would be 99% sure that the gasket is leaking. This is rather common. You could TRY tightening the bolts but very unlikely that it will help. Re-torque these mounting bolts to about 200 inch lbs., carefully.

Walt Conner

I used to work in a car dealership and prep new cars. Customers would bring them back complaining of rattles, leaks, etc.

We would try to get a visual on where the leaks were coming from, and then clean the engines.

Where we thought a leak was coming from, we would use a carpet cleaner that dried to a powder and sprayed the suspect areas and drive and come back and check for discoloration. The spray dries white and then when a leak comes thru it turns brown or the color of the fluid.

I hope this helps.

Steve

thanks a bunch Walt... i'll lyk how it goes.

hey, if anyone has a general "how to" on replacing a sump gasket it would be a big help :)

rtb

I used to work in a car dealership and prep new cars. Customers would bring them back complaining of rattles, leaks, etc.
We would try to get a visual on where the leaks were coming from, and then clean the engines.

Where we thought a leak was coming from, we would use a carpet cleaner that dried to a powder and sprayed the suspect areas and drive and come back and check for discoloration. The spray dries white and then when a leak comes thru it turns brown or the color of the fluid.

I hope this helps.
-----------------

thanks a bunch Steve... where would i get something like this?

on a similar note, i was talking to my neighbor today and he mentioned something called "Liquid Gasket"? from his description it sounded like a paste-like substance you can use to seal leaks.

anyone heard of this or something similar?

Walt, i also got the mower by my local Cub Cadet dealer and the guy there took a look at it and seconded your thoughts about the sump gasket so i'm gonna move forward with this UNLESS this liquid gasket stuff is worth trying out.

anyone?

1.remove lower belt-s from engine pulley-s.
2. remove 4 bolts that hold engine to frame of machine.
3. disconnect any fuel lines, electrical wiring, battery ground cable from battery, and cable to starter from solenoid. Drain engine oil. If not sure what wires go where, before taking them apart, use some masking tape on them for idento tags, and mark them for reassembly!
4. See if there is a large hole in frame where lower end of crankshaft goes down thru it. If hole is large, lower double pulley can remain on the shaft, to be removed later. If hole is small, remove lower pulleys before removing engine.
5. Set engine on bench, upside down. Remove all bolts that hold sump onto engine block. Carefully lift sump off the engine block. Clean any broken gasket material from sump and block. Try not to disturb the cam or crankshaft while doing this part. Clean sump out. Remove old crank-shaft seal, and install a new one. (Observe how the old one was installed! There is a right way and a wrong way!)
6. A small amount of wheel bearing grease on the block edges will help to hold the new gasket in place.
7. carefully slip the sump down over the crankshaft, trying to not disturb the oil slinger/ cam gear line-up.
8. after sump is back on and down fully, tap it slightly with a hammer handle, then install all the bolts in the holes. Tighten in a cross-ways pattern, hand snug at first, then progressively tighter as you go, until you can't turn them any more with yer wrenches!
9. reassemble the whole thing, and you should be good to go!

10. Don't forget the oil in the engine!!

B&S has had so much trouble with sump gaskets, especially on the 28 & 31 series engines, that I use Copper Coat on all sump gaskets.

Walt Conner

thanks so much Walt and Rusty and everyone else that cared enough to reply - it really is appreciated.

i got the new gasket in and put the sump back on. i wish i had seen your directions prior to starting Rusty - things would have gone a little smoother.

while putting the screwing the screws that hold the sump to the rest of the engine i was using a torque wrench and at about 20ft/lbs one of the screws got loose all the sudden so i was sure it was broken.

well, it wasn't broken but probably even worse it stripped the screw hole out. i loosened it back up and took it out and there was aluminum wrapped around the screw :(

i take it that this thing is history as i have thought about it and really don't see a way around replacing the whole engine block?

thanks so much for your excellent replies and instructions - i should have had someone else do it but didn't want to pay to have it done so i guess i got what i paid for. thanks again.

Get a thread repair kit and glue a stud in the stripped hole and don't torque so much next time.

yeah, Walt told me to torque it to 200 INCH/LBS not 200 FT/LBS - i take it there's a bit of a differnce :(

so this is repairable? where would i find a thread repair kit? internet?

thanks for the reply.

First thing I would do is try a longer bolt. Don't know which hole you stripped out but the hole may just be deep enough and have enough threads to hold. Check the depth of the threads and you will likely have to cut the bolt off to ensure that you are thightening against the base and not bottoming out in the bolt hole. Put a nut on the bolt before cutting it off so the nut will "chase" the threads as you remove it or perhaps you have the threading die. You may want to use something like Loc-Tite, thread sealer to help the shorter threads stay tight. You may have to use something like helicoil or some other type of thread insert available at you local auto parts store such as NAPA. If you aren't comfortable doing this yourself, you may want to have an auto machine shop do it.

As a last resort, you could check to see if there appears to be enough metal to permit taping to the next larger size, 3/8". Be carefull here and I don't like to do that. You will need to drill the hole in the sump larger then to clear the larger bolt.

Walt Conner

ok i checked the legnth of the hole and it seems to be pretty shallow. when i stripped the bolt all the aluminum wrapped around the bolt was at the very bottom of the bolt though so i'm not sure if the upper threads are damaged or just the ones at the bottome of the hole.

if i cut the bolt off some and use some loctite could i use the upper threads in the hole?

also, putting the nut on there is for when i cut the bolt the nut will keep the bolt threads inline when i remove the nut?

not sure what a "threading die" is so no, i probably don't have that.

i have been reading a little on the helicoils since last night. do i have to do any drilling - other than screwing in the helicoil plug?

i'll wait for a response before running off and stripping more bolts this time :)

OH YEAH, what about a thread insert Walt? or is that just for spark plugs? i saw a post a while back while searching and thought i'd ask about it.

"i'm not sure if the upper threads are damaged or just the ones at the bottome of the hole."

No way.

"if i cut the bolt off some and use some loctite could i use the upper threads in the hole?"

I am talking about cutting off a LONGER bolt, not the one you stripped out and that only IF the hole, threads go deeper than where the threads stripped.

IF the threads at the bottom of the hole are stripped, the threads all the way up are as well.

"putting the nut on there is for when i cut the bolt the nut will keep the bolt threads inline when i remove the nut?"

Yes.

"what about a thread insert "

You have to drill the hole and tap to fit the Heli-Coil or any other type of thread insert that I know of. Since Heli-Coil is a trade name, thread insert is the generic name, there are different types.

Can you tell us WHICH hole you stripped the threads in?

Walt Conner

it's this one...

{{gwi:140553}}

...the bolt right below the red square. you know i'm beginning to think this may have been the problem all along - as it's right where the leak occured and i know i didn't tighten this bolt no more than i did any of the others.

i also remember saying all of these bolts seemed to come off a lot easier than i thought they would but i don't remember this one being any looser than the others though.

i'm can only imagine the number of times you've heard this Walt, but you've done it again!

i bought the thread insert kit, thread locker (didn't have loctite), and a longer bolt just incase i got lucky.

i started taking the kit out of the packaging and thought to try the longer bolt first. i screwed it in and it was too long by about a 1/4 inch so i marked it, found a nut and screwed it on, and hacksawed the extra off.

then i put a generous amount of thread locker on the bolt and screwed her in and she tightened right up! i thought it was bottoming out but the lock washer was flat and it felt tight.

i didn't have the guts to back it out so we'll see how it goes tomorrow (well later today) when i get it all back togther. hopefully, it's good and tight and the leak is fixed.

ttys.

rtb

"didn't have the guts to back it out so we'll see how it goes tomorrow"

I wouldn't have either. IF it is torqued to spec. I wouldn't touch it again unless absolutle necessary.

Still another alternative IF absolutely need, before a new block etc., would be to drill the existing hole even deeper and run a tap threading it even deeper. That is why I wanted to see which hole was stripped. This is a touchy operation. Looks like the hole that originally was leaking?

Now do me a favor and email me what camera you used for the pictures and how you got them from the camera into your post. I think you have my email address.

Walt Conner

"I wouldn't have either. IF it is torqued to spec. I wouldn't touch it again unless absolutle necessary."

yeah, trust me i won't - hopefully it is in there good and will withstand the vibration of the engine.

"Looks like the hole that originally was leaking?"

yes, the leak was right above this screw... i'm starting to think the guy probably stripped the screw and put some thread lock or something similar on it and just screwed it back in there.

after i realized it was stripped i pulled it out and it had what looked like some really lightweight aluminum or aluminum-like substance wrapped in the grooves of the bolt. this of course could be aluminum but seemed to be a little too brittle for engine aluminum. again, this is just a guess.

"Now do me a favor and email me what camera you used for the pictures and how you got them from the camera into your post. I think you have my email address."

sure thing! i'd be glad to Walt. the camera is a Fuji e510 5 megapixel digital camera that i've been happy with... they should be quite affordable now as i got it for $150 or so after rebate almost a year ago.

i'll get that email to you in a bit.

Walt, i thought i could get your email from the "my page" link next to your name but i guess not?

So, you'll have to post your address or send it to me at tb40nd at gmail dot com.

TTYS.

RTB