Oil Blow Back Issues

[DLB]

ok heres the deal. I put a new exhaust on my bike couple years ago and a new air breather (spear type). Now im getting alot of oil blowback from crankcase breather. im sure it has alot to do with the exhaust being straight pipes sucking air back. i tried taking the crankcase breather off and piping it straight to the breather. i got worse blowback coming out of my pushrod tubes. so now im scratching my head on what to do. any ideas? thnx for any input. BTW the bike is a 2001 prosport with a mikuni carb in case anyone needs to know for diagnosing the issue.

 

[LamboV12]

ok heres the deal. I put a new exhaust on my bike couple years ago and a new air breather (spear type). Now im getting alot of oil blowback from crankcase breather. im sure it has alot to do with the exhaust being straight pipes sucking air back. i tried taking the crankcase breather off and piping it straight to the breather. i got worse blowback coming out of my pushrod tubes. so now im scratching my head on what to do. any ideas? thnx for any input. BTW the bike is a 2001 prosport with a mikuni carb in case anyone needs to know for diagnosing the issue.

U shoul have a small plastic in line fitting with a one way check valve to prevent blow back - think it may be an ss part. Rember getting
mine from local bike shop

 

[DLB]

that does make sense but, im thinking i would still run into the problem of having the blowback come out of my pushrod tubes.

 

[Th3InfamousI]

U shoul have a small plastic in line fitting with a one way check valve to prevent blow back - think it may be an ss part. Rember getting
mine from local bike shop

He has an 01 - They do not have the 1 way check valve.



Most common thing for blow back is over filling the oil. Have you let it blow it out and recheck the level? My 04 has less blow back when the oil level is below the recommended level. I have a separate oil pressure gauge which I monitor and the pressure is normal therefore I know I have enough oil in the system to let it sump correctly.

Something to think about...just as a note the older SSW engines from S&S are known for excessive oil blow back. Hence why they redesigned the system in 2005. A lot of guys ran a puke can so it didn't end up all over the bike. I run my crank breather to the ground.

 

[Mr. Wright]

My 03 did that this last summer. I knew I wasn't over full on the oil. I changed the O-rings on the push rod tubes, and the valve cover o-ring gaskets. That gasket has little flapper on it that covers where the breather lines come out of the rocker boxes. That must have been my problem, because it doesn't blow oil anymore.

 

[DLB]

thanks for the input guys ill look into doing that!

 

[Wills67]

Hey Eric,

We need to get together so I can see what you did. I'm still getting oil all over my pipes and oil res.

See ya!

He has an 01 - They do not have the 1 way check valve.



Most common thing for blow back is over filling the oil. Have you let it blow it out and recheck the level? My 04 has less blow back when the oil level is below the recommended level. I have a separate oil pressure gauge which I monitor and the pressure is normal therefore I know I have enough oil in the system to let it sump correctly.

Something to think about...just as a note the older SSW engines from S&S are known for excessive oil blow back. Hence why they redesigned the system in 2005. A lot of guys ran a puke can so it didn't end up all over the bike. I run my crank breather to the ground.