smoke from a hill

[fordboy]

Alright, guys, yall have help me with all of my problems. Here is a HARD one. My craftsman riding mower (which is mentioned on another post) is a great mower. Tough as nails. The only thing is that while the blades are engauged, and i am going down a certain hill, it will let out a huge plume of smoke and stall. It will start back easily, and not smoke. I dont understand why it only does this on ONE CERTAIN HILL, and would like to know what you think.
thanks

 

[Tom_T]

What color is the smoke? Is the crankcase overfilled leading to oil flooding through the breather into the carb? Does the engine have a float carb that might be flooding out when tilted?

Do I always answer a question with a question?

 

[Johnny]

Is there a hump on this hill causing the blade to hi-side and bog down causing the belt to slip and smoke, then stalling the engine?

 

[SnakeOil]

Your piston(s) in that motor move back towards you and then forward towards the front of the mower. When you tilt forward, oil may be sneaking from the back side of the piston to the the other side in the combustion chamber. This could extinguish the flame due to the lower volatility of motor oil.

Much blue smoke would be present before and after.

 

[fordboy]

it is white smoke. It is NOT overfilled

 

[JTK]

Along the same lines of SnakeOil's theory, what is happening here is a fairly common occurrence on vertical shaft engines, especially the V-twin variety. If you go in a nose-down situation, oil from the sump can blow past the piston rings and get into the cylinders. The result is a HUGE cloud of smoke. White, grey or whatever, it's oil. The only thing that's gonna smoke like that on an air cooled engine is burning engine oil. Nature of the beast. Oil sump to cylinder position is such that it's easy for oil to get in there. Overfilling, even slightly, will aggravate the situation.

Joel

 

[Tom_T]

Oil slosh could be the cause, if the hill is so steep to cause the engine to die out you might be mindful of rollover. Doesn't quite explain the no smoke on restart though.

 

[ksJoe]

If the oil is full, drain to half way between full & add.

My grandfather's snapper with a briggs does that on a hill when the oil is full. It has a crank breather tube that goes to air filter box. If we take the air filter cover off after it smokes, their is oil it.

 

[c3po]

Is this an oil slinger type lubrication system, or is it a full pressure lubrication system with an oil filter, just curious.

 

[Fabmanrich]

I've been in the same situation, mine has a 26hp Kohler. Going nose first down a hill I always mowed with my old mower. (went downhill instead of sideways so I wouldn't tip over) Big cloud of smoke, scared the [censored] out of me, mower was brand new. Oil level was good, not overfilled.

My solution was to not go down thw really steep part, use the trimmer more. Might try the suggestion of having oil half way between full and add, not all the way full.

Richie

 

[Fabmanrich]

Originally Posted By: Fabmanrich
I've been in the same situation, mine has a 26hp Kohler. Going nose first down a hill I always mowed with my old mower. (went downhill instead of sideways so I wouldn't tip over) Big cloud of smoke, scared the [censored] out of me, mower was brand new. Oil level was good, not overfilled.

My solution was to not go down thw really steep part, use the trimmer more. Might try the suggestion of having oil half way between full and add, not all the way full.

Richie

 

[JTK]

Richie, in the short term, you won't hurt anyting but the mosquitos. Still a good plan though to not go into such a steep nose down for safety reasons. Given the jug to sump orientation of horizontal shaft engines, you don't run into the smoke show situation with those.

Joel

 

[fordboy]

Originally Posted By: c3po
Is this an oil slinger type lubrication system, or is it a full pressure lubrication system with an oil filter, just curious.


Pressure system with an oil filter