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Clouds of smoke on start up
#1
C
charleneje
C
charleneje
Craftsman 21HP 46" cut, Model 91728852, engine B&S Platinum 331977
I have written about this mower before, I just don't know what to do anymore I went out to use the mower this afternoon and there was thick smoke coming out of the exhaust and it kept on stopping so I continued restarting it and after about 45 mins I managed to keep it running not at normal speed but it did run I tried to drive it around my yard to see if it would clear out yard is 3/4 acre it stopped halfway around the yard when I finally got it running again it would not drive the transmission acted up anyway after messing with it for a while I managed to get it to drive back to my house. There is alot of sprayed oil under the hood and under the fuel pump or whatever is attached to the side at the left rear top of the engine air cover it sprayed oil over the chassis and front of the mower deck. I have replaced the head gasket numerous times the last time I worked on the head to get it good and flat and then put an annealed solid copper gasket on it, I also replaced the carburetor and it had run just great until I parked it for 3 weeks as I said, can anybody give me good suggestions before I cart it of to the scrap yard. I bought this mower new in 2014 and it has given me nothing but trouble ever since I brought it home from Sears never will I buy another Craftsman mower again, I had several used Craftsman mowers that gave me excellent service but its obvious Craftsman mowers are not worth buying anymore. Guess I will go to work on my old Allis Chalmer 916H and get it running again.
#2
H
hlw49
H
hlw49
Check the engine oil to see if it is over full from gas leaking into the crank case from the carb or maybe even fuel pump.
#4
C
charleneje
C
charleneje
Hi the oil is barely showing on the dipstick and the spark plug is looking good it isn't fouled at all. Thank you for your suggestions someone here suggested taking it apart to see if the rings had broken causing pressure in the crankcase my problem with that is I am not only 71 yrs of age but I'm disabled as well stopping me from lifting the engine out I have checked and the most I can lift is 40lbs. When I said here I meant a nieghbor
#6
S
slomo
S
slomo
Does it have an oil filter? Is it leaking there? You said oil was spraying all under the hood.
Oil dipstick loose or no O-ring on the under side of the stick?
Breather hose not connected?
Oil dipstick loose or no O-ring on the under side of the stick?
Breather hose not connected?
#7
C
charleneje
C
charleneje
Thanks for the suggestion the oil filter is tight there is a breather with small tubes attached to the plastic engine shroud at the rear the down facing tube from that was spraying oil onto the mowing deck. The mower sprayed oil out of the exhaust I don't know if the oil had drained from the engine into the muffler or if the engine cylinder had filled with oil but the smoke was so thick when it did run that I could not see through it and it just about ran like that for about 45 minutes it was just as well it was outside and the wind blew from behind me blowing smoke away from me I started it the following day and it tried to run ok but then ran out of gas, I have been to busy to get more gas and work on it anymore. I had to undo the dipstick to check the oil so I guess oil wasn't coming out of there.Does it have an oil filter? Is it leaking there? You said oil was spraying all under the hood.
Oil dipstick loose or no O-ring on the under side of the stick?
Breather hose not connected?
#8
S
slomo
S
slomo
Sounds like someone has been playing around with the engine. Are you saying a breather hose is OPEN and points down towards the deck?
Post up several pictures so we can see what you are working with.
Post up several pictures so we can see what you are working with.
#9
C
charleneje
C
charleneje
yes there is a breather system that attaches to the dipstick tube. I took the plastic engine shroud of and also took of the tappet cover when that came loose alot of oil poured out it smelt strongly of gasoline, I previously replaced the carb the last time I changed the head gasket. SLOMO you might remember that occasion because you was trying to help me then, but then I imagine you helped alot of people, I was the one that didnt connect the wire to the bottom of the carb and the engine wouldn't run properly, until I connected the wire the next day anyway it ran good for a few weeks until I didn't use it for a couple weeks then this problem started I am guessing the engine filled up with gas out of the fuel tank while it was sitting, I am putting pictures up as requested plus a picture of where the exhaust blew oil out for 45 minutes that is the mower 2 pic, the mower1 pic I highlighted the breather control or whatever it is, the others are pictures of the engine after getting sprayed with oil. The breather control in mower pic 1 doesn't seem to do anything but that is how it has always been from new, one tube from the dipstick tube leads to it then couple of tubes of it go nowhere. I figure I will just turn the gas of when the mower is sitting I had already put on a turn off valve as seen in the pictures. Any advice would be very welcome.Sounds like someone has been playing around with the engine. Are you saying a breather hose is OPEN and points down towards the deck?
Post up several pictures so we can see what you are working with.
Attachments
#10
B
bertsmobile1
B
bertsmobile1
That is the impulse fuel pump because the engine or at least the blower housing is off something else.
If it is blowing oil out the hole then the diaphragm inside is busted.
If you have a gravity system ( tank higher than the carb ) then you don't need it so block off the tube at the dip stick or get a repacement dip stick without the outlet .
If it is blowing oil out the hole then the diaphragm inside is busted.
If you have a gravity system ( tank higher than the carb ) then you don't need it so block off the tube at the dip stick or get a repacement dip stick without the outlet .
#11
C
charleneje
Thanks for solving that problem for me.
Now I have to solve the problem of the carburetor draining fuel through into the engine I believe through the engine breather attached to the inlet manifold when this all first happened I took the head of and the head gasket was blown since then I put two more head gaskets on this engine the last one I bought a solid copper annealed by the company I bought it from, I checked the head with an engineers straight edge and it was warped so I glued sandpaper to a large piece of glass and sanded it in an hourglass pattern until the surface was perfectly flat and then put it together, I also replaced the carburetor with a new one and put a shutoff valve on the fuel line unfortunately last time I used the mower I didn't turn the gas valve off. I always use pure gasoline in my mowers I don't use any with alcohol in it.
What is the part sticking out of the bottom of the float chamber do? isn't that supposed to be an electronic shut of valve or something like it? My books only show me so much I do appreciate all the help I can get thanks.
C
charleneje
Okay thanks I wondered what it was supposed to do I saw there was a fuel pump listed in Briggs and Stratton parts listing but no pictures I wondered why the tubes on it didn't go anywhere, what I don't understand is why it was there in the first place I bought this mower new from Sears.That is the impulse fuel pump because the engine or at least the blower housing is off something else.
If it is blowing oil out the hole then the diaphragm inside is busted.
If you have a gravity system ( tank higher than the carb ) then you don't need it so block off the tube at the dip stick or get a repacement dip stick without the outlet .
Thanks for solving that problem for me.
Now I have to solve the problem of the carburetor draining fuel through into the engine I believe through the engine breather attached to the inlet manifold when this all first happened I took the head of and the head gasket was blown since then I put two more head gaskets on this engine the last one I bought a solid copper annealed by the company I bought it from, I checked the head with an engineers straight edge and it was warped so I glued sandpaper to a large piece of glass and sanded it in an hourglass pattern until the surface was perfectly flat and then put it together, I also replaced the carburetor with a new one and put a shutoff valve on the fuel line unfortunately last time I used the mower I didn't turn the gas valve off. I always use pure gasoline in my mowers I don't use any with alcohol in it.
What is the part sticking out of the bottom of the float chamber do? isn't that supposed to be an electronic shut of valve or something like it? My books only show me so much I do appreciate all the help I can get thanks.
#12
H
hlw49
H
hlw49
That will be a fuel shut off solenoid but does not prevent fuel from entering the carb. It stops fuel from being drawn into the main jet and helps keep engine from back firing on shut down. From what U R describing it sound to me like U have a blown head gasket. Thought the fuel pump is inoperative and there are no hoses hooked to the other fittings. A blown head gasket will blow oil out the little brass filter on the side of the fuel pump and if the fuel pump has a ruptured diaphragm it can blow it out the other fittings as well. It will also blow it into the air filter chamber through the breather tube. If it is blowing oil out the hole in the fuel pump it does not mean the diaphragm is ruptured that little brass fitting is a filter so dirt will not be drawn into the engine. U cannot run a crank case pulse diaphragm without a vent to relieve the extra pressure so the diaphragm can flex. Did U change the oil. If not please do.
#13
C
charleneje
Right now I am reluctant to pull the head yet again because everything is pointing at my fuel tank emptying into the carb which inturn runs it into the engine via the 1/2 inch breather going from the inlet manifold to the engine. I am no expert but somehow my engine is filling with gasoline and that is the logical way for it to happen unless the fuel is going into the inlet manifold and running down the valve stem into the engine both are possibilities. so wouldn't I cure the immediate problem by turning the gas off after using it everytime. I really appreciate all the information I have got from all the people that have written on this post and my previous ones all of my previous posts were about this same problem.
C
charleneje
Hi thanks for your reply, the brass filter is still in place the oil was coming out of the unused fittings that pump has never been attached to anything other than the dipstick tube unless the fittings were blown undone when the first head gasket blew they did pour oil out back then and the oil in the engine had gasoline in it as well. I changed that head gasket and the oil and filter and drove it around my yard and parked it when I went to use it the next day there was alot of smoke and it would not run properly so I believed the head gasket had blown again I changed it a second time but it didnt look blown drove it around the yard and cut the grass and parked it for a week, Next time I went to cut the grass it was pumping out smoke again and fuel in the oil so I parked it and went back to working on it again this year, this year I took it apart once again the head gasket didnt look blown but I put a straight edge on the head and it had highs and lows in strange areas, I ordered a solid copper head gasket and asked for it to be annealed glued sand paper to a glass panel and sanded the head until it showed no distortion at all using an engineers straight edge put it all back together complete with a new carb and once I got it back together properly it ran fantastic for a few weeks I then parked it for close to two weeks and when I started it up it blew thick smoke and oil out of the exhaust for about 45 minutes and it also blew oil out of the fuel pump you mentioned that part being I have checked the oil it is more gasoline than oil so will need changing again I will also change the filter.That will be a fuel shut off solenoid but does not prevent fuel from entering the carb. It stops fuel from being drawn into the main jet and helps keep engine from back firing on shut down. From what U R describing it sound to me like U have a blown head gasket. Thought the fuel pump is inoperative and there are no hoses hooked to the other fittings. A blown head gasket will blow oil out the little brass filter on the side of the fuel pump and if the fuel pump has a ruptured diaphragm it can blow it out the other fittings as well. It will also blow it into the air filter chamber through the breather tube. If it is blowing oil out the hole in the fuel pump it does not mean the diaphragm is ruptured that little brass fitting is a filter so dirt will not be drawn into the engine. U cannot run a crank case pulse diaphragm without a vent to relieve the extra pressure so the diaphragm can flex. Did U change the oil. If not please do.
Right now I am reluctant to pull the head yet again because everything is pointing at my fuel tank emptying into the carb which inturn runs it into the engine via the 1/2 inch breather going from the inlet manifold to the engine. I am no expert but somehow my engine is filling with gasoline and that is the logical way for it to happen unless the fuel is going into the inlet manifold and running down the valve stem into the engine both are possibilities. so wouldn't I cure the immediate problem by turning the gas off after using it everytime. I really appreciate all the information I have got from all the people that have written on this post and my previous ones all of my previous posts were about this same problem.
#14
H
hlw49
H
hlw49
Yes change the oil if U have been running with all the fuel in the engine U will have to clear all that out. Then see what happens.
#15
B
bertsmobile1
B
bertsmobile1
Inside the fuel pump is a rubber diaphragm and a light spring
The variations in crankcase pressure causes the diaphragm to move in & out .
The brass filter allows excess pressure to vent off .
Because the output end has been open it will have allowed the rummer diaphragm to dry out and crack.
The crankcase fume will always have little droplets of oil in it which is intentional to lubricate the engine .
So the tube from the dipstick will always have some oil in it.
When a leaking carburettor dilutes the oil in the crankcase then you get more droplets of oil in the fume.
In fact oil oozing out of the brass filter is a sign of an overful crank or a leaking head gasket .
The variations in crankcase pressure causes the diaphragm to move in & out .
The brass filter allows excess pressure to vent off .
Because the output end has been open it will have allowed the rummer diaphragm to dry out and crack.
The crankcase fume will always have little droplets of oil in it which is intentional to lubricate the engine .
So the tube from the dipstick will always have some oil in it.
When a leaking carburettor dilutes the oil in the crankcase then you get more droplets of oil in the fume.
In fact oil oozing out of the brass filter is a sign of an overful crank or a leaking head gasket .
#16
C
charleneje
C
charleneje
Bertsmobile, thanks for the information that scenario was what made me start to look to a blown head gasket at the beginning of this year long problem with this engine, fuel in the oil was then so bad I had to drain oil out to do the checks for the blown head gasket. I would like to find out how the tubes on the pump are supposed to be connected but I can't find any diagrams anywhere. I actually have begun to wonder if this mower was returned to Sears and they just turned around and sold it to me it wasn't boxed or crated and they drove it of the loading dock into the bed of my truck, there just has to be a reason I have had nothing but trouble with it since I bought it new. If I get it running and sell it I feel like I would be cheating the buyer so will keep it or take it to the salvage yard. I do thank you for your information and advise.Inside the fuel pump is a rubber diaphragm and a light spring
The variations in crankcase pressure causes the diaphragm to move in & out .
The brass filter allows excess pressure to vent off .
Because the output end has been open it will have allowed the rummer diaphragm to dry out and crack.
The crankcase fume will always have little droplets of oil in it which is intentional to lubricate the engine .
So the tube from the dipstick will always have some oil in it.
When a leaking carburettor dilutes the oil in the crankcase then you get more droplets of oil in the fume.
In fact oil oozing out of the brass filter is a sign of an overful crank or a leaking head gasket .
#17
B
bertsmobile1
B
bertsmobile1
The one that goes in the round face is the impulse line from the dip stick tube
The one next to it on the side is fuel in and the one that has nothing on it poining down is fuel to the carb.
The one next to it on the side is fuel in and the one that has nothing on it poining down is fuel to the carb.
#18
H
hlw49
H
hlw49
U know there is one thing we may be missing. This engine could have a bad crank case breather or rendered inoperative by the fuel pump . Now the fuel in the oil is not related to crank case breather it would have to be carb related. Is it saturating the air filter with oil? U know since it is blowing oil out the fitting barbs on the fuel pump. There should be not way the fuel pump is blowing oil out the fittings unless the diaphragm is ruptured. Since there are no fuel lines running to it, it serves no purpose . Due to the fact it is spewing oil out the fittings I would take the line off going to the fuel pump and plug the fitting on the dipstick. If the diaphragm is ruptured as it would appear to be this would render the crank case breather inoperative. The crank case breather works like this it allows crank case pressure to escape to keep from building pressure in the crank case and blowing the seal out of the engine. It does not allow outside air to be drawn back into the engine as this would fill the low pressure created in the crank case to be filled with outside air and create a high pressure instead of a low pressure. Plug the fitting on the dipstick and see it your problem goes away. I know this sound a little funny but it was the best way I knew to get what I wanted across. Thanks 4 your patience. We had a Briggs twin that would not run at a place where I use to work another shop put a new carb on it and it still would not run. The tech that was working on it decided to run a cc vacuum test. Back in those days we only had manometers this is the old type where U take a piece of clear hose and make a u out of it on a board and put water in it. As water seeks it own level the water would be the same height in both sides of the u. U then hook one end of the manometer to the cc and read the inches of water vacuum marked on the board. When he hooked it up he said it is working and moving the water in the tube. I took one look at it and yes it is but it is pushing the water away from the cc instead of drawing it toward it indicating a pressure. Briggs replaced the engine and called for it back I think they said the oil return passages were not drilled in the head.Hi thanks for your reply, the brass filter is still in place the oil was coming out of the unused fittings that pump has never been attached to anything other than the dipstick tube unless the fittings were blown undone when the first head gasket blew they did pour oil out back then and the oil in the engine had gasoline in it as well. I changed that head gasket and the oil and filter and drove it around my yard and parked it when I went to use it the next day there was alot of smoke and it would not run properly so I believed the head gasket had blown again I changed it a second time but it didnt look blown drove it around the yard and cut the grass and parked it for a week, Next time I went to cut the grass it was pumping out smoke again and fuel in the oil so I parked it and went back to working on it again this year, this year I took it apart once again the head gasket didnt look blown but I put a straight edge on the head and it had highs and lows in strange areas, I ordered a solid copper head gasket and asked for it to be annealed glued sand paper to a glass panel and sanded the head until it showed no distortion at all using an engineers straight edge put it all back together complete with a new carb and once I got it back together properly it ran fantastic for a few weeks I then parked it for close to two weeks and when I started it up it blew thick smoke and oil out of the exhaust for about 45 minutes and it also blew oil out of the fuel pump you mentioned that part being I have checked the oil it is more gasoline than oil so will need changing again I will also change the filter.
Right now I am reluctant to pull the head yet again because everything is pointing at my fuel tank emptying into the carb which inturn runs it into the engine via the 1/2 inch breather going from the inlet manifold to the engine. I am no expert but somehow my engine is filling with gasoline and that is the logical way for it to happen unless the fuel is going into the inlet manifold and running down the valve stem into the engine both are possibilities. so wouldn't I cure the immediate problem by turning the gas off after using it everytime. I really appreciate all the information I have got from all the people that have written on this post and my previous ones all of my previous posts were about this same problem.