pjmule
XS650 Member
The bolt that holds the oil filter on the right side has a check valve. Should the screw be tightened till it stops or is the tension adjustable on the ball and spring? When I took mine out I noticed that the screw wasn't tight.
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oil filter check valve
- Thread starter pjmule
- Start date
pamcopete
Ride.Enjoy.Life is Simple
pjmule,
That is the pressure relief or bypass valve. I do not know of a published procedure to set it. The nominal pressure of the system is 14 PSI, but you will only encounter that with a cold engine. Just set the screw about at the half way point.
That is the pressure relief or bypass valve. I do not know of a published procedure to set it. The nominal pressure of the system is 14 PSI, but you will only encounter that with a cold engine. Just set the screw about at the half way point.
IIRC the screw is tightened till it seats, the spring sets the correct relief pressure.
pjmule
XS650 Member
Gary, what's IIRC ?
I always set it just flush with the end of the bolt. Tighten till it stops takes all the play out of the spring and the ball can't move.
Leo
Leo
um oh yeah; If I Remember Correctly
Sounds like I don't
Sounds like I don't
pamcopete
Ride.Enjoy.Life is Simple
Well, just to add to the confusion, I replaced my ball and spring with just a threaded stud that eliminates the pressure relief function. I didn't want junk bypassing the filter on startup.
The bypass is there supposedly to prevent engine damage due to oil starvation in the event that the screen gets plugged up with some junk from a self destructing engine. The problem with that idea is that the bypass would open and let the junk bypass the filter in order to save the engine? I don't think so.
Also, the junk would have to get past the sump filter, so that could only happen if the sump filter had a hole in it, which it often does, but I think that the hole is made by the increased flow of thick cold oil and that the flow increases when the bypass valve opens, so keeping it closed will help prevent a hole in the sump screen, except that not having a bypass valve means that you should have an oil pressure gage so you do not exceed 14 PSI when the oil is cold. I did install an oil pressure gage when I eliminated the bypass valve and my sump screen lasted 13 years and 60,000 miles so I guess it works.
The bypass is there supposedly to prevent engine damage due to oil starvation in the event that the screen gets plugged up with some junk from a self destructing engine. The problem with that idea is that the bypass would open and let the junk bypass the filter in order to save the engine? I don't think so.
Also, the junk would have to get past the sump filter, so that could only happen if the sump filter had a hole in it, which it often does, but I think that the hole is made by the increased flow of thick cold oil and that the flow increases when the bypass valve opens, so keeping it closed will help prevent a hole in the sump screen, except that not having a bypass valve means that you should have an oil pressure gage so you do not exceed 14 PSI when the oil is cold. I did install an oil pressure gage when I eliminated the bypass valve and my sump screen lasted 13 years and 60,000 miles so I guess it works.
pjmule
XS650 Member
How do you not exceed 14 PSI when the oil is cold with an oil pressure gage?
pamcopete
Ride.Enjoy.Life is Simple
pjmule,
Oil pressure is directly proportional to engine speed, so I keep the revs down during warm up.The gage is mounted right in front of me. I keep an eye on the pressure during warm up and don't move until I know it will not exceed 14 PSI at 3,000 RPM. I keep the revs down and shift gears when the pressure gets to 14 PSI until the oil warms up. After the engine warms up, the pressure is about 5 to 7 PSI @ 3,000 RPM, so no need to watch it anymore.
The other purpose of the bypass valve is to protect the filter from excessive pressure when the oil is cold, but the sump screen does not have a bypass valve, so the cold oil flow is actually increased when the bypass opens and that is what I think holes the sump screen. The early models had the bypass valve installed in the oil pump, so when that valve opened, it relieved pressure on both the sump screen and the filter. Don't know why Yamaha changed that design, except perhaps to save some production costs.
Oil pressure is directly proportional to engine speed, so I keep the revs down during warm up.The gage is mounted right in front of me. I keep an eye on the pressure during warm up and don't move until I know it will not exceed 14 PSI at 3,000 RPM. I keep the revs down and shift gears when the pressure gets to 14 PSI until the oil warms up. After the engine warms up, the pressure is about 5 to 7 PSI @ 3,000 RPM, so no need to watch it anymore.
The other purpose of the bypass valve is to protect the filter from excessive pressure when the oil is cold, but the sump screen does not have a bypass valve, so the cold oil flow is actually increased when the bypass opens and that is what I think holes the sump screen. The early models had the bypass valve installed in the oil pump, so when that valve opened, it relieved pressure on both the sump screen and the filter. Don't know why Yamaha changed that design, except perhaps to save some production costs.
pjmule
XS650 Member
Wow, thanks for the education! I never thought a simple question about tension on a ball and spring could be so helpful .
Michaelo
650Mick
Interesting thread, I've left the setting of the pressure relief valve as I found it, what I've noticed yesterday when doing my 1000 mile oil change was the setting had moved, the screw was nearly flush with the face of the screen.
So the mechanic in me was looking at why? Did a quick search on the forum and didn't find anything definitive about the setting. Without a pressure gauge on the bike it's difficult to define what the correct position is.
Also noticed the main sump plate screen is slightly deformed, so I am assuming that there has been a higher flow rate going through. Like others I warm my engine up before riding, so that leads me to believe that the further the screw is out, the less pressure is obtained at the bypass point?
Mick
So the mechanic in me was looking at why? Did a quick search on the forum and didn't find anything definitive about the setting. Without a pressure gauge on the bike it's difficult to define what the correct position is.
Also noticed the main sump plate screen is slightly deformed, so I am assuming that there has been a higher flow rate going through. Like others I warm my engine up before riding, so that leads me to believe that the further the screw is out, the less pressure is obtained at the bypass point?
- So do we know what the factory setting is at all?
- Is there a recommended setting?
Mick
Hey, Mick! Have a look at these:
http://www.xs650.com/threads/oil-filter.72/
http://www.xs650.com/threads/oil-pressure-insights.39578/
On mine, the side-filter bypass valve screw settings have always been flush with the end of the filter bolthead.
http://www.xs650.com/threads/oil-filter.72/
http://www.xs650.com/threads/oil-pressure-insights.39578/
On mine, the side-filter bypass valve screw settings have always been flush with the end of the filter bolthead.
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