# Oil leak



## MGD (Aug 1, 2010)

Hello, 
I have an LT1000 craftsman lawn tractor. Can an improperly adjusted carb cause oil to leak from under the oil cap when tractor is mowing under load? I did check the oil level and it is not overfilled...if anything it could use a bit. I recently installed a new carb and am sure I did not have it set correctly as my plug keeps getting fouled up.


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## lsmurphy (Sep 12, 2008)

Your oil breather is clogged. You need to take it apart and clean the element or replace it. Pressure is building up in the crankcase and the pressure needs to come out somewhere. Generally the oil vapor/pressure is relieved through the breather to the carb intake and cycled through combustion and out the exhaust.

Scott


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## MGD (Aug 1, 2010)

Scott,
Is the oil breather the rubber hose that comes off the carb and goes to the engine? Can you give me a little more guidance as I am new to all this.Thanks


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## lsmurphy (Sep 12, 2008)

Yes, follow the rubber tube to a cover on the block...that is the breather. Should be one or two bolts that secures the breather cover, remove and you should see an element...or what's left of it...clean or replace.



Scott


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## MGD (Aug 1, 2010)

Thanks,
I actually started to figure it out except now it looks like I will need to remove the flywheel to be able to remove the second bolt that secures the breather assembly. I assume I will need a special tool(s) (Brake and puller) for this or is there a way around it with basic tools? Thank you. You have been very helpful.. I'm learning a lot.

Marco


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## dangeroustoys56 (Jul 26, 2010)

I use a c clamp to hold the flywheel in place while i unbolt the flywheel nut, id buy a steering wheel puller ( has 2 outer holes and a threaded center hole- spray the area around the center of the flywheel with PB blaster ( make it come off a lil easier) - then crank the center bolt down and itll make a 'bang' noise when it pops loose ( its a tapered shaft/press fit)- replace the shear key when re assembling it.


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## MGD (Aug 1, 2010)

Well, I successfully removed the flywheel using a strap wrench to hold it in place while unbolting the nut. I cleaned the oil breather assembly and put everything back together. I have not tested the system yet. My next task is to adjust the carb which I presume was responsible for the carb deposits fouling the plug. CAn someone help me with this?I read somewhere to back off the idle mixture and idle screw 1.5 turns and to go from there. How do I know when I have made the right adjustments?


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## dangeroustoys56 (Jul 26, 2010)

lightly bottom the fuel mixture screw, then back it out 1 1/2 to 2 turns - fire up the tractor and adjust it till the motor stumbles then back it off till it smooths out- that should be in the ballpark.

The air mix screw i just leave at 1 1/2- 2 turns. The fouling most likely was from the oil pouring into the carb.


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## MGD (Aug 1, 2010)

Ok, while trying to adjust the carb having the engine running of course, I noticed that oil is still leaking from under the oil cap to the dipstick. After having cleaned the oil assembly which did not appear particularly dirty inside, I did change the oil and made sure to not overfill the tank. As for the carb, if this means anything or potentially influnences the symptoms of my tractor, when I replaced the carb the model that replaced the walbro is now a nikki carb. There are two adjustment screws. Following a diagram in a briggs and stratton small engine care and repair book, the screw closest to the throttle lever they call the idle mixture screw and the second adjustment screw more centered in the body of the carb is the idle speed screw. I did back the idle mixture screw 1.5 turns. IN the book they say when you turn the screw clockwise, the engine should slow down and the opposite is true when turned counterclockwise. However, I find the opposite is true when following these directions. They then recommend the idle speed screw be set with a tachometer which I do not have. At this pointI am pretty frustrated. WHat else would cause the oil pressure to increase if the oil breather is not clogged?


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## MGD (Aug 1, 2010)

What about a blown head gasket? If this helps I haven't noticed the smell of gas in the oil nor any sign of oil in the air filter. When I discovered the problem, I noticed smoke from time to time while mowing and then the engine started to run poorly. I immediately stopped mowing to inspect. I saw oil had leaked from the oil cap and also pulled the plug and noticed it was black. After scrapped the plug a bit I was able to get it going again runnning smoothly but yet again same thing would happen. That Is why i attributed the fouled plug to the carb not adjusted correctly.


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## dangeroustoys56 (Jul 26, 2010)

Could be a bad head gasket- that motor is an OHV - right? Its hard to tell whats going on- if the gas is overflowing the carb and flooding the oil - it wouldnt necessarily come out the cap- if the breather is plugged itd cause excess pressure in the motor ... i have a 12HP OHV teccy with a bad breather or valve seals - it literally pukes oil from the breather tube, floods the carb with oil and reburns it- it saturated the air filter element with oil ...

The bad thing about OHV motors is the whole valve train needs to come out to pull the head off, then needs to be all reset again.


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## IH farm boy (Aug 29, 2010)

i would compression check the motor and make sure you dont have bad or broken rings , if you dont have a compression tester turn it buy hand if it spins over with out to much trouble its got problems


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## MGD (Aug 1, 2010)

*A single puff of white smoke*

I did replace the head gasket which resolved my problems. Today I topped off the oil because I found the level on the dip stick to be at the add end of the range. While using the tractor and I have a bit of a slope on my yard, at one point while all was running well, a great big puff of white smoke was emitted. No noise and no change in performance. I quickly shut everything off and examined the engine. No leaks were noted but the dip stick was unscrewed and I know I closed it after adding the oil. I checked the oil and this time it appears there wasa too much oil in the engine, unless it was streaking on the dipstick. I drained it to the appropriate level and everything was fine. Did I blow another gasket? Damage anything? If this was a result of too much oil, It would then appear that when the dip stick reads that the level is at the top end of the acceptable range it is really too much? What is the correct way to check the oil. Engine cold vs hot, dip stick screwed in all the way or just seated?


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## Chipmaker (Sep 16, 2003)

Your manual should tell you how to read the dipstick or where it should be to read it. My JD has it on the dipstick, and says not to turn cap on but to just set dipstick cap on top of filler tube to get oil level. One day before I changed the oil I played with it, and found if I screw the dipstick in, for a reading, it becomes almost half a quart low when measured.


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## dangeroustoys56 (Jul 26, 2010)

When i check my oil on the fleet - i screw the cap all the way back on, then take it back out and check it again sitting on top . Either way if its in the acceptable range on the stick- it should be fine.

I also check it when the motor is cold.


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