blowing oil

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  #1  
Old 08-22-09, 11:04 PM
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blowing oil

hello everyone, first post here.
briggs and stratton
model-19g412
type-1180-e2
code-9912171b
coleman powermate generator
10 hp-5000
my generator has set for a while and when i started it, it was blowing oil from the breather tube. (a lot of oil). i have changed the oil and put a new head gasket on and a new breather and rubber breather tube. while the heads were off i sprayed wd-40 on the piston to soak in in case the rings might be stuck a little. the motor runs good as long as the breather tube is pointed away from the carb so it doesnt pull the oil into the carb. this motor hasnt got many hours on it and the valves and piston didnt have much build up on them. the gas tank and carb have been drained every time i have put it in storage. can anyone help diagnose this problem? it seems to run too good for the rings to be shot. does not smoke when running.
 
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  #2  
Old 08-23-09, 02:10 AM
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Does the oil smell like gas? Is the oil level over-full?
 
  #3  
Old 08-23-09, 06:26 AM
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i didnt smell any gas in it and the level is to the top of the fill hole like it said in the manual. it doesnt have a dipstick, it has the bottom fill. i let it run for a while yesterday and blow a lot of oil out. enough came out that it wouldnt start back because of the low oil shutdown.it never did shut itself down from the low oil shutdown, it just wouldnt start back till i added more. can you disable the low oil switch? maybe run it a little low to check it.
 
  #4  
Old 08-24-09, 01:41 AM
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The head gasket wouldn't cause your problem and if the oil is not running out the fill, then it's not too full. I think you have bad rings and/or cylinder.
 
  #5  
Old 08-24-09, 07:06 AM
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As Cheese pointed out, if rings are worn or cracked, or cylinder walls damaged it can result in excessive crankcase pressure. There are a couple of ways to determine cylinder condition without disassembling the engine.

Water Manometer (Easy to make and best for the problem you have)

The water manometer measures the amount of vacuum created by the engine as the piston travels to TDC. Bad piston rings will lead to very low water manometer readings. Most manuals will have the standard manometer readings for each engine.

Leakdown Test

The leak-down tester will measure the amount of air lost out of your compression system. Ten to fifteen percent air loss is bad. If you have that kind of air loss, locate the leak by listening for air. Remove the oil filler cap and listen in the crankcase. If you can hear air escaping compression is being lost through the rings.

Here are some helpful links:

PER Notebook - Those Messy Oil Leaks


How To Make An Engine Cylinder Leak Down Tester


Building and Using a Cylinder Leakdown Tester


Leak-down tester - Wikipedia, the free encyclopedia


- Harbor Freight Tools - Quality Tools at the Lowest Prices
 
  #6  
Old 08-24-09, 07:29 PM
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thanks for the quick replys gentlemen. the leak down tester sounds like just what i need to do. ive got all the stuff laying around to make one and ill try it on my next day off and post back the results. thanks again guys.
 
  #7  
Old 08-24-09, 08:13 PM
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I've had this problem on Briggs a couple of times. An air leak can affect crank case pressure. I have had two different causes for this. One a bad intake valve seal and two if your head gasket blows between the cylinder and the hole the push rods are in it can do what you are describing. I have seen the head gasket do this more that once. While I tell every one to do a leak down test neither a leak down or a compression test will tell you anything when the gasket in blown internally.--Matt
 
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Old 08-25-09, 06:55 PM
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The head gasket cannot cause this problem on this engine. It is impossible. It's not an ohv engine. A leakdown test will in fact reveal a blown head gasket, blown internally or externally.

If you had a valve seal cause a crankcase leak problem then the valve guide must have been worn so badly the valve was flopping around in it.
 
  #9  
Old 08-26-09, 06:41 AM
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Cheese is correct. I mentioned both the manometer and leakdown tester because either will let you know if the cylinder is the problems source and the monometer is easy to make. Since you have the parts to build a leakdown tester by all means do so.

The leakdown tester, along with a stethoscope, is a valuable tool to have.

Here are some notes I have concerning the leakdown tester:

Hold the crankshaft to prevent injury.

Listen (stethoscope) for compressed air escaping.

Remove the oil filler cap and listen in the crankcase. If you can hear air escaping compression is being lost through the rings.

At the muffler: air escaping through the muffler is exhaust valve leaking.

At the carburetor: air escaping through the carburetor is an intake valve leaking.

Around head gasket: if you can hear the leak spray the area with soap solution and if leaking it will show up as bubbles.

Rotate piston to TDC, don't go past TDC and then back. If the rings are not seated against the bottom of the lands, your readings will be low.

The leakdown test is normally done on a warm engine. This is particularly important on air-cooled engines where normal cylinder clearances are large when the engine is cold. When an engine will not start then you have to test it cold.
 
  #10  
Old 08-26-09, 10:34 PM
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Excellent instruction/description Airman.
 
  #11  
Old 08-30-09, 08:39 AM
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Talking

good news on this motor. i made the leak down tester and found it was the exaust valve leaking. i lapped the valve and checked valve clearance and put it back together. i got it started and let it run about 30 minutes and had no blowback. i then hooked up my hobart 187 welder to the generator and it ran it just fine. thank you gentlemen for your replies and expert advise. the leakdown tester worked great and has been put in a drawer with my prized possessions. thanks again for your good advise.
 
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