# [SOLVED] B&S 12hp on a Snapper RER Mower ~ loosing oil when stood on end



## BrotherJim (Apr 19, 2011)

I'm loosing about 8 ounces of oil every 30-45 minutes the Snapper RER mower is stood up on end to work beneath (The snapper is designed to be stood on end for this). It's only loosing oil at this high rate, when the mower is stood up.

The engine is a 12hp Briggs & Stratton 283707 0136-01 9211244D. As you can see by the code, it was built in 1992. I bought the used mower last week and don't know the history on the engine. It cranks right up and runs strong (electric start).

I think the crankshaft seal is leaking/weeping slightly on the PTO end and now I'm wondering if it's also leaking on the magneto end of the crankshaft as well. The thing is, oil doesn't appear to be pooling around the flywheel even though I can't pull start (to see if it slings oil) because apparently there is a faulty starter clutch. The rope pulls and rewinds but doesn't turn the engine over. 

When I electric start, oil doesn't sling everywhere. 

Most if not all the lost oil while standing on end seems to be pooling and running out from the area behind/beneath the starter shroud cover.

Are there any other possiblities other than the top (magneto side) crankshaft seal ??

Thanks 














































What my buddy boy, Rowdy, thinks of the evil lawn maintenance device LOL










A common area for oil leaks/weeping is at the base of the oil filler tube where the tube mates with the oil sump cover.
... That's not where all this oil is coming from. You can partially see the starter in the picture below (starter shroud is center bottom of picture) and the oil is running out from under the starter shroud cover which is fastened to the engine cover. Could it be coming from anywhere other than out of the top/magneto side, crankshaft oil seal ??


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## Basementgeek (Feb 7, 2005)

*Re: B&S 12hp on a Snapper RER Mower ~ loosing oil when stood on end*

Hi and welcome to TSF :wave:

Are you positive that is made to stand on end? I think the bar in back is to protect the engine only. Engine don't like being turned on their side.

May be leaking from crank case breather.

BG


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## BrotherJim (Apr 19, 2011)

*Re: B&S 12hp on a Snapper RER Mower ~ loosing oil when stood on end*

Thank you for the welcome !!!

Yes, I'm absolutely VERY sure it's designed to stand on end for service and repairs. It's even recommended to do so in the owners manual. Although, there is no mention of sustained oil loss.

In fact, one of the preferred methods of long term non-use storage such as during winter months, is to stand on end so as not to take up a lot of horizontal storage space. The owners manual describes steps of this type storage and doesn't even recommend draining the oil first.

Where is the crankcase breather located on the B&S 12HP L-head engine ??


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## K-B (Oct 24, 2005)

*Re: B&S 12hp on a Snapper RER Mower ~ loosing oil when stood on end*

Those are designed to be stood on end for storage and maintenance. It should not leak oil, at least not at a high rate.

It could be the top seal, however you should notice some leaking while the engine is running. It may not be noticeable because of the more severe leakage from standing on it's end. But it could also be the breather like BG mentioned. Also, make sure the engine is not overfilled with oil.

EDIT: After looking at the diagram, I see that the breather is located on the inside crankcase, (would be on top when the machine is stood up), so that can be ruled out. I would go ahead and remove the flywheel to have a look at the seal.


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## BrotherJim (Apr 19, 2011)

*Re: B&S 12hp on a Snapper RER Mower ~ loosing oil when stood on end*

Thanks K-B !!!

I intend to pull the engine within the next couple of months to replace the oil seal in the sump cover on the PTO side any way. There is no hurry, because it's running really well ... doesn't smoke at all ... and the only time it looses oil at this sustained rate is when stood on end. I just wanted some input on any other areas to look for leaks when stood on end, besides oil seals on either end of the crankshaft.

I've just last night ordered an appropriate B&S Service and Repair Manual #270962 and am just "pre-staging" knowledge and information before pulling the engine.

Again, Thanks !!!


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## Basementgeek (Feb 7, 2005)

*Re: B&S 12hp on a Snapper RER Mower ~ loosing oil when stood on end*

Unless there is a real need to stand on end after every use, I would suggest you don't. At the end of the season, sure, after you remove the battery and gas and drain the oil.

You have a old mower, if it is running good, I would leave it as it is.

Just an opinion.

BG


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## BrotherJim (Apr 19, 2011)

*Re: B&S 12hp on a Snapper RER Mower ~ loosing oil when stood on end*

The Snapper mower is designed to be stood on end and has been designed as such for the last 50 years or so, as well as the current models. The problem is, the engine has developed a leak that I need to fix.

The advice of not to follow standard procedure and recommendations provided by the manufacturer is the same as if I said ... don't turn on your computer when connected to the internet unless you have to, because you might download some drive-by malware. That would be laughable would it not ??

But I see where you're coming from. It's old, baby it and get all you can out of it. But my view is that it's a classic, easy to work on ... usually ... tough and reliable when properly repaired and maintained. In other words ... it's not a throw-away mower. I intend to keep it a. long. time.


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## BrotherJim (Apr 19, 2011)

*Re: B&S 12hp on a Snapper RER Mower ~ loosing oil when stood on end*

Eureka !!! I found the problem WOooHOoo !!!
Something had gotten onto and eaten the surface of the oil filler tube. In the picture below, you can see the porosity on the plastic oil filler tube. That is the starter shroud and engine cover right behind it. Anyway, around behind the filler tube where you can't see, the plastic was "eaten" through and leaking oil. As the engine was running, oil pressure was throwing a little oil at a time behind and beneath the starter shroud and engine cover. 
Oil would drip out from behind the shroud/cover as well as leak from the filler tube with the mower stood on end. In the upright position, the filler tube doesn't leak unless the engine is running with built up oil pressure and even then it isn't as bad as when stood on end and oil is just sitting in the tube.
$12 fix for the oil fill assembly including dip stick, tube and seals. My local parts house won't have the parts until later this week though. But thats all good.










Sometimes I guess we overlook the obvious. Possible case and point ...


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## K-B (Oct 24, 2005)

*Re: B&S 12hp on a Snapper RER Mower ~ loosing oil when stood on end*

Good deal. Glad you figured it out.


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