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oil comming out of crank case breather
#1
R
rocky4
R
rocky4
I have a B&S 331707 0115-B1 17.5 HP engine. Has oil being blown out through crank case breather passage. No blue smoke coming from exhaust.
Oil is not over filled and does not smell of gas. Removed breather passage assy and was full of oil. The reed is in place. Any help?
Thanks in advance
Oil is not over filled and does not smell of gas. Removed breather passage assy and was full of oil. The reed is in place. Any help?
Thanks in advance
#2
gfp55
Is the reed valve working correctly. Did you have the mower tipped up like when cleaning the bottom or changing/sharpening the blade. If yes, sometimes the oil will fill the breather passage with oil and blowby will blow the oil out when the engine is run. Keep us posted.
gfp55
I have a B&S 331707 0115-B1 17.5 HP engine. Has oil being blown out through crank case breather passage. No blue smoke coming from exhaust.
Oil is not over filled and does not smell of gas. Removed breather passage assy and was full of oil. The reed is in place. Any help?
Thanks in advance
Is the reed valve working correctly. Did you have the mower tipped up like when cleaning the bottom or changing/sharpening the blade. If yes, sometimes the oil will fill the breather passage with oil and blowby will blow the oil out when the engine is run. Keep us posted.
#3
R
rocky4
Thanks for replying
This is a murray riding mower. I just finished rebuilding the motor.Had to replace the piston and rod. I looked at the reed,looks ok but not sure what to look for in way of not working. Motor runs great and has 80 lbs pressure. What is the purpose of the reed and how does it work? Could a bad piston ring cause this problem?
R
rocky4
Is the reed valve working correctly. Did you have the mower tipped up like when cleaning the bottom or changing/sharpening the blade. If yes, sometimes the oil will fill the breather passage with oil and blowby will blow the oil out when the engine is run. Keep us posted.
Thanks for replying
This is a murray riding mower. I just finished rebuilding the motor.Had to replace the piston and rod. I looked at the reed,looks ok but not sure what to look for in way of not working. Motor runs great and has 80 lbs pressure. What is the purpose of the reed and how does it work? Could a bad piston ring cause this problem?
#4
gfp55
80 psi seems kinda high, if the oil pressure is too high and the reed valve is only good to 60-65 psi then you will get oil coming out the breather. What is the max oil pressure for that engine? What are the specs for that engine? Yes a bad ring will cause blowby and high oil pressure, because gases are leaking passed the rings into the crankcase. Does the engine have a fuel pump? If yes what type?
gfp55
Thanks for replying
This is a murray riding mower. I just finished rebuilding the motor.Had to replace the piston and rod. I looked at the reed,looks ok but not sure what to look for in way of not working. Motor runs great and has 80 lbs pressure. What is the purpose of the reed and how does it work? Could a bad piston ring cause this problem?
80 psi seems kinda high, if the oil pressure is too high and the reed valve is only good to 60-65 psi then you will get oil coming out the breather. What is the max oil pressure for that engine? What are the specs for that engine? Yes a bad ring will cause blowby and high oil pressure, because gases are leaking passed the rings into the crankcase. Does the engine have a fuel pump? If yes what type?
#5
M
Mikel1
The breather valve aka reed maintains crankcase pressure. On piston up stroke closes and on piston down stroke opens.
Did you reuse the old rings?
M
Mikel1
What is the purpose of the reed and how does it work? Could a bad piston ring cause this problem?
The breather valve aka reed maintains crankcase pressure. On piston up stroke closes and on piston down stroke opens.
Did you reuse the old rings?
#6
R
rocky4
Yes, I did use old rings.
R
rocky4
The breather valve aka reed maintains crankcase pressure. On piston up stroke closes and on piston down stroke opens.
Did you reuse the old rings?
Yes, I did use old rings.
#7
R
Rivets
R
Rivets
Did you make sure that the ring end gaps were 120 degrees apart when you installed the piston. If the end gaps were near each other, that would create a lot of blowby and be the cause of your problem. Also, did you check the end gap before installing them on the piston. If they are too large, that would be another cause. This is an overhead valve engine, did you replace the intake valve seal? Could also be a blow head gasket. Too many possibilities. This is going to make you into a detective to solve this one.
#8
M
Mikel1
Did you check the ring end gaps?
I guess I was typing at the same time as Rivets,lol
M
Mikel1
Yes, I did use old rings.
Did you check the ring end gaps?
I guess I was typing at the same time as Rivets,lol
#9
R
rocky4
I really don't know what the specks are. Has no fuel pump. Its a B&S, 17.5 ohv, 331707 0115-B1 engine.
Does anyone know what the compression should be on this engine?
R
rocky4
80 psi seems kinda high, if the oil pressure is too high and the reed valve is only good to 60-65 psi then you will get oil coming out the breather. What is the max oil pressure for that engine? What are the specs for that engine? Yes a bad ring will cause blowby and high oil pressure, because gases are leaking passed the rings into the crankcase. Does the engine have a fuel pump? If yes what type?
I really don't know what the specks are. Has no fuel pump. Its a B&S, 17.5 ohv, 331707 0115-B1 engine.
Does anyone know what the compression should be on this engine?
#10
gfp55
If I were you I would get a service/shop manual for your engine. I don't want to insult you but if you are going to "rebuild" an engine you don't reuse rings. A engine service/shop manual will give you a step by step run down to correctly rebuild an engine. It will have all the info you will need. Did you reuse the head gasket? Did you torque the head bolts in the correct order? I see others are helping you also now.
gfp55
I really don't know what the specks are. Has no fuel pump. Its a B&S, 17.5 ohv, 331707 0115-B1 engine.
Does anyone know what the compression should be on this engine?
If I were you I would get a service/shop manual for your engine. I don't want to insult you but if you are going to "rebuild" an engine you don't reuse rings. A engine service/shop manual will give you a step by step run down to correctly rebuild an engine. It will have all the info you will need. Did you reuse the head gasket? Did you torque the head bolts in the correct order? I see others are helping you also now.
#11
R
rocky4
You are right, I should not have used the old rings. I have a new head gasket and sump gasket. Bolts were torqued in correct order and to spces (I do have these specifications) I'm going back and replace the rings with new ones and do a complete check out. Really appreciate all the help. I have an email in to B&S engineer for compression on engine, if he answers back.
R
rocky4
If I were you I would get a service/shop manual for your engine. I don't want to insult you but if you are going to "rebuild" an engine you don't reuse rings. A engine service/shop manual will give you a step by step run down to correctly rebuild an engine. It will have all the info you will need. Did you reuse the head gasket? Did you torque the head bolts in the correct order? I see others are helping you also now.
You are right, I should not have used the old rings. I have a new head gasket and sump gasket. Bolts were torqued in correct order and to spces (I do have these specifications) I'm going back and replace the rings with new ones and do a complete check out. Really appreciate all the help. I have an email in to B&S engineer for compression on engine, if he answers back.
#12
gfp55
gfp55
If you use the search box on this site you may find a manual. There is a guy on this forum that is always post manuals, mechanic mark, I think is his name. Maybe if you post a thread saying you need one he might find one for you. mechanic mark is forever posting manuals on here.You are right, I should not have used the old rings. I have a new head gasket and sump gasket. Bolts were torqued in correct order and to spces (I do have these specifications) I'm going back and replace the rings with new ones and do a complete check out. Really appreciate all the help. I have an email in to B&S engineer for compression on engine, if he answers back.
#13
R
rocky4
Thanks for your assistance. I received a reply from a engineer at B&S about the compression, Could be high as 125 psi.
R
rocky4
80 psi seems kinda high, if the oil pressure is too high and the reed valve is only good to 60-65 psi then you will get oil coming out the breather. What is the max oil pressure for that engine? What are the specs for that engine? Yes a bad ring will cause blowby and high oil pressure, because gases are leaking passed the rings into the crankcase. Does the engine have a fuel pump? If yes what type?
Thanks for your assistance. I received a reply from a engineer at B&S about the compression, Could be high as 125 psi.
#14
gfp55
Sorry about the misunderstanding, I misread and thought "80 lbs pressure" was oil pressure. So your saying your engine has 80 lbs pressure, the compression is 80 lbs. 80 psi is way low, you have loads of blowby.
gfp55
Thanks for your assistance. I received a reply from a engineer at B&S about the compression, Could be high as 125 psi.
Sorry about the misunderstanding, I misread and thought "80 lbs pressure" was oil pressure. So your saying your engine has 80 lbs pressure, the compression is 80 lbs. 80 psi is way low, you have loads of blowby.
#15
M
motoman
M
motoman
With due respect. Before you install rings the bore and piston need attention. If the bore is not reasonable round (spec) , tapered, and scratched new rings will not work properly. The piston(s) should be checked for cracks and the ring lands (grooves) have clearance specs (feeler gauge). Discussion has centered on excess ring end gap, but insufficient ring end gap (spec) can cause ring breakage. The bore must be honed properly for oil rentention during ring break in. These are things the home mechanic can check or have checked. Sorry if this seems late . On high miles /hours engines lots can get out of spec. Hope you are able to correct your problem and good luck.
#16
gfp55
Yes I agree, Thats why I have said to get a manual, read it and follow it, so all the parts involved with an engine rebuild are covered and you will have a good sound engine when your done.
gfp55
If I were you I would get a service/shop manual for your engine. I don't want to insult you but if you are going to "rebuild" an engine you don't reuse rings. A engine service/shop manual will give you a step by step run down to correctly rebuild an engine. It will have all the info you will need. Did you reuse the head gasket? Did you torque the head bolts in the correct order? I see others are helping you also now.
If you use the search box on this site you may find a manual. There is a guy on this forum that is always post manuals, mechanic mark, I think is his name. Maybe if you post a thread saying you need one he might find one for you. mechanic mark is forever posting manuals on here.
With due respect. Before you install rings the bore and piston need attention. If the bore is not reasonable round (spec) , tapered, and scratched new rings will not work properly. The piston(s) should be checked for cracks and the ring lands (grooves) have clearance specs (feeler gauge). Discussion has centered on excess ring end gap, but insufficient ring end gap (spec) can cause ring breakage. The bore must be honed properly for oil rentention during ring break in. These are things the home mechanic can check or have checked. Sorry if this seems late . On high miles /hours engines lots can get out of spec. Hope you are able to correct your problem and good luck.
Yes I agree, Thats why I have said to get a manual, read it and follow it, so all the parts involved with an engine rebuild are covered and you will have a good sound engine when your done.