Air filter getting wet

[Gabrial.Mitch]

I have a new Toro lawn mower, Briggs & Stratton engine. Model 20053. I've been using it since the last week of May. I mow about 6-8 lawns per week, and last week I noticed that the mower would let out a think white smoke when I start it, since then I only prime the mower twice instead of thrice. Now, yesterday I decided to clean my whole mower, and found that there was gas and/or oil on the air filter. Now you're probably thinking, that leaned it over on the air filter side, but I assure you that everytime I've leaned to mower over, the air filter side was up. So I use a paper towel and squeeze the oil/gas out of the Styrofoam around the filter. I dry the case, which is also oily. I mow my lawn, and afterwards I see that there is new oil around the case, and on the filter.

I figured maybe I have too much oil, so I checked it about 10 times, and it seems fine, I didn't even put much oil in the machine, it says it can take 591ml and I put about 500 and it was at the full line.

Any help? Thanks. Mitch

[Meat Plow]

Oil from the sump is getting blown back into the filter through the carb. I would expect to see a little of it knowing the heavy use the mower is getting but it could be a sign of other problems. Does it use any oil or smoke after that initial puff? Maybe there is a crankcase breather that is plugged? If it's under warranty have it looked at.

[Gabrial.Mitch]

No, just the initial puff, then it runs fine. "crankcase breather that is plugged" What is a crankcase breather? I decided I'd post here before driving out the the Toro shop. Mitch

[Meat Plow]

Crankcase breather traditionally allowed some outside air through a filter membrane of various shapes and designs located somewhere on the engine to mix with the crankcase air during operation. But come to think of it with today's tight emissions, crank byproducts would get recirculated back into the engine via a shunt into the intake manifold. If this is the case then you could be seeing this in your filter because of an incomplete sealing of a valve causing excessive blow back pressure in the manifold.

[Oren]

Good point about the crankcase breather (Meat Plow).

Check the condition of the spark plug firing end. Compare it to this chart and see if something is seriously wrong like a valve seal or piston ring.

-- Oren

"I don't have anything against work. I just figure, why deprive somebody who really loves it."

[Oren]

Get the Operator's and Parts' Manuals here*. We don't have the serial number for the model. At least one of these models has a crankcase breather. Maybe 2 inches long and 1 inch or so wide.

Look next to the exhaust pipe, but it will be mounted on the block and not the engine head. This cover is also called a tappet cover and has a gasket and breather. With the cover off you will see both valves exposed (good for seeing a stuck/damaged valve.

Clean the breather..

-- Oren

"I don't have anything against work. I just figure, why deprive somebody who really loves it."

[Stormin Mormon]

The crankcase breathers I've seen allow air out of the crankcase when the piston goes "down", or into the crankcase. When the piston goes up, the valve closes. This maintains a very slight negative pressure, and helps cut down on oil leakage.

[Oren]

Not a pro here, but I've always thought of the breather as the direct method for un-spent/burnt gases to escape. During the intake air we don't want exhaust fumes to enter the head.

A clogged breather can prevent the escape of the gases and not vent the block.

-- Oren

"I don't have anything against work. I just figure, why deprive somebody who really loves it."

[Meat Plow]

Breather allows the crankcase to breath since there is a lot of air moving around on the non combustion side of the engine also. Like Stormin mentioned it's an oil conservation thing.

My forte is 2 strokers though. Rebuilt my own durtbike motors down to the last needle bearing. Used to race unlimited class (360cc and above) in what they called around here a "Hare Scramble." No money in it or national recognitions but it was a great way to break bones and the chix loved it too (watch us race) :)

[Oren]

I would not have considered it oil conservation so much. But I do know not to run the engine without it :-))

I've just always thouht of ventilation as the most important function of the crankcase breather.

I had one 360. The cop finally had to ask. Is this the bike that out-ran me the other night? No Sir!!

-- Oren

"I don't have anything against work. I just figure, why deprive somebody who really loves it."

[Meat Plow]

And really it is. Especially in a motor that depends on motor parts splashing the oil around from the sump instead of it being pumped.

Back when I was racing it was pretty rural here. One county Deputy assigned to our township who knew better than to chase me :)

[Oren]

If the valves seat tightly and seals - do not leak, there is very little chance for oil to enter the chamber covered by the breather.

The breather wants to release gases, so they do not return to the combustion chamber through a valve and or misfire and send a puff of smoke out the exhaust.

You're not old to enough to have run moonshine :-))

Jr. Johnson went from moonshine to "stock car", now NASCAR.

Movie _White Lightening_

-- Oren

"I don't have anything against work. I just figure, why deprive somebody who really loves it."

[Meat Plow]

Ideally, but small engines that aren't oil pressurized wear quickly.

I'd have to go tear my 6.5 hp Toro Personal Pace apart to be sure but I'd bet that crank by products are reburned these days because of state emission laws. Hell they even put cat converters on Harleys sold in California.

I've seen the movie. And no I'm not old enough but my one uncle who was born in Byrdsville Ky ran shine. I would never ride with him if my aunt wasn't with us. Well I lied, I rode with him just once :)

[Stormin Mormon]

Please supply some more details. Vent gasses from where, to where? Prevent gas from venting from where, to where? And what is this "from the block" you mention?

[Stormin Mormon]

From what I understand, the major reason for a crankcase breather is so that the pressure of the piston going "down" doesn't pressurize the crankcase. The internal air pressure tends to blow oil out any leaky seal, or gap in the gasket.

[Meat Plow]

FWIW my Honda Harmony 6hp has a tube coming out the block (assume breather) and it attaches to the intake about 1.5" from the head. Just looked at it today when I changed the air filter.

[Oren]

Please don't :) I had not even thought of Emission Control. After all the years of owning my power washer I didn't pay attention.

I really hate to ride with a friend..he is color blind and I'm not sure what he sees for light colors, etc...

-- Oren

"I don't have anything against work. I just figure, why deprive somebody who really loves it."

[Oren]

I see I'm lacking the point about the "down" stroke and that pressure building up.

I've taken that for granted and the "real" purpose of the breather.

I seemed to have been stuck on "ventilation" and by that I mean, if the engine was seriously flooded the gases would leak into the crankcase breather chamber (open valve) and would be vented out this breather. Say a valve was bent or a weak spring or a broken valve seal; then these fumes/gases may leak into the chamber and be vented outside. These are cases of engine damage, but where combustibles get into the breather chamber.

I get the real purpose now... preventing pressure by ventilation :-)

Clear as mud? :-)) NOT!

-- Oren

"I don't have anything against work. I just figure, why deprive somebody who really loves it."