Ok, I have a hand me down huskee lawn mower with a 17.5 HP B&S intek I/C. If i am mowing on a steep-ish angle, "passenger side" down, I get a [censored] load of smoke and a stalled lawn mower - I assume this is oil burning. If i avoid this situation, in effect by keeping extreme angles to the other side, there appears to be no ill effects and I can mow as normal. Anybody have a clue what gives?
Smoke and stall...
- Thread starter El_Schaf
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Don't have one, and never seen one, but is there a crank-case vent hose from somewhere on the side of the motor to the carb. Some motors have a vent from the crank-case to the carb. Usually there is a thin wall black rubber tube from this vent set-up to the carb. Could be that when you tilt the motor so the oil level submerges the crank-case vent, the oil will have to flow because of the bypass leakage of the valves, and piston pressurizes the crank-case. And when the oil level covers the crank-case vent oil is forced into the vent hose instead of crank-case gases.
If this is going on, and you must use it at that type of angle, the only thing I could think to do would be to close off the current crank case vent, and install one on a higher point on the motor, such as above the valves. However usually crank-case vents have a baffle, or even a valve set up to prevent too much oil from leaving the engine with the by-pass gases, and a simple vent might allow too much oil to leave. Something like a PCV valve on a old 8 cycinder might be a good idea to include if you do move the crank-case vent to a higher point.
If this is going on, and you must use it at that type of angle, the only thing I could think to do would be to close off the current crank case vent, and install one on a higher point on the motor, such as above the valves. However usually crank-case vents have a baffle, or even a valve set up to prevent too much oil from leaving the engine with the by-pass gases, and a simple vent might allow too much oil to leave. Something like a PCV valve on a old 8 cycinder might be a good idea to include if you do move the crank-case vent to a higher point.
Yeah, you're blowing oil into your intake via the crankcase breather. Easiest thing to do is change the way you're mowing. Also, take off the breather apparatus and soak it in gas to free it up in case it's got gunked up and to make sure it's working properly. Changing the location of the breather opening is going to be more trouble than it's worth.
Of course, first things first, make sure you haven't got the thing over filled. It could be as simple as that.
Of course, first things first, make sure you haven't got the thing over filled. It could be as simple as that.
BTW, If you are tilting it that much you could be in danger of rooling it over. Every year several people get killed in rool-overs. Do not take the danger of a rool over too lightly. It can kill you in the rool-over, or trap you under it and burn you to death when the gas combines with the hot engine and exhaust.
JTK
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+1 to the overfull crankcase. I've had several larger vertical shaft OHV riding mower engines exhibit this behavior on inclines. If the engine does this, you need to lower the oil level to between the full and add marks. Preferably a tad towards the "add". Had a 17hp Kawasaki do it, a 17.5hp Briggs Intek "AVS" and now even my new Kohler Courage V-twin will do it if the oil is at the "full" line. The plume out of the V-twin is impressive.. or very scary depending how you feel about it!
OTOH, none of the horizontal shaft engines I've owned will do this. My theory is because there's no (easy) way for oil to slosh from the crankcase to the combustion chamber on horizontal shafters.
Joel
OTOH, none of the horizontal shaft engines I've owned will do this. My theory is because there's no (easy) way for oil to slosh from the crankcase to the combustion chamber on horizontal shafters.
Joel
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Originally Posted By: El_Schaf
If i am mowing on a steep-ish angle, "passenger side" down
If you're mowing "passenger side" down on a "steep-ish" angle, then you're a rollover waiting to happen. Especially if it's so steep that it causes the engine to start belching smoke and stall.
Steep hills and ditches should be mowed up and down, never along their length.
If i am mowing on a steep-ish angle, "passenger side" down
If you're mowing "passenger side" down on a "steep-ish" angle, then you're a rollover waiting to happen. Especially if it's so steep that it causes the engine to start belching smoke and stall.
Steep hills and ditches should be mowed up and down, never along their length.
If you are mowing at such an angle that you are getting that much oil into the combustion chamber, you are also starving the engine of oil. Most vertical shaft Briggs engines are splash lube, even if they have an oil filter. They have an oil slinger and a small pump that just pumps oil through the filter. Briggs says no more than 20 degrees in any one direction. Granted if this is just for a few seconds, no damage is done.
As others have mentioned, the rollover risk is the first concern.
As others have mentioned, the rollover risk is the first concern.
Originally Posted By: Pop_Rivit
Originally Posted By: El_Schaf
If i am mowing on a steep-ish angle, "passenger side" down
If you're mowing "passenger side" down on a "steep-ish" angle, then you're a rollover waiting to happen. Especially if it's so steep that it causes the engine to start belching smoke and stall.
Steep hills and ditches should be mowed up and down, never along their length.
Lesson learned - I'm avoiding the ditches (where this happened) and just going to trim with the weed eater. Mower worked perfectly yesterday.
Originally Posted By: El_Schaf
If i am mowing on a steep-ish angle, "passenger side" down
If you're mowing "passenger side" down on a "steep-ish" angle, then you're a rollover waiting to happen. Especially if it's so steep that it causes the engine to start belching smoke and stall.
Steep hills and ditches should be mowed up and down, never along their length.
Lesson learned - I'm avoiding the ditches (where this happened) and just going to trim with the weed eater. Mower worked perfectly yesterday.
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