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Discussion Starter #1
Can anyone tell me why my oil leaves my tank goes into engine and comes right out of engine vent hole.
New rebuild on first start up
 

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Hopalong
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Sheared or missing key on return side of the pump? Blocked oil lines/filter return? Incorrect routing of oil lines?
 

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Discussion Starter #4
Thermodyne, I think I may have screwed up breather timing also. It was something that came to mind after I buttoned
it up. Kind of new at this. Thanks for confirming that possibility. Tearing it down tonight, I'll let you know

Tom E.
 

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Can anyone tell me why my oil leaves my tank goes into engine and comes right out of engine vent hole.
New rebuild on first start up
Are you using the wrong oil filter? All Harley engines before the Twin Cam run the oil filters on the return-line which is not pressurized.

A couple years ago this guy in front of me was asking the parts guy about wanting the newest Twin Cam after-market oil filter for his EVO because it had a ridiculously small micron rating to trap more particles.

The parts dude explained something about (not exact quote) that the pressurized Twin Cams oil filter's check valve, which is not used on non-pressurized oil filters, would cause oil to puke out of the carb thru the head vents because the low pressure return-line can't deal with the check valve.

He said just looking at the open end of the filter shows which you have...plastic behind the holes around the top means check valve, no plastic, no valve.

Until that moment I didn't know there was that much difference between my '82 FXRS Shovelhead and '03 Twin Cam RK's oiling system, I just order the best filter for the make/model/year.

Now I can't help but to look thru the top each oil change. ANYWAYS...I'm sure none of us are as lucky to be something so simple, but maybe check it out before you tear too far into it.
 

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Discussion Starter #6
Are you using the wrong oil filter? All Harley engines before the Twin Cam run the oil filters on the return-line which is not pressurized.

A couple years ago this guy in front of me was asking the parts guy about wanting the newest Twin Cam after-market oil filter for his EVO because it had a ridiculously small micron rating to trap more particles.

The parts dude explained something about (not exact quote) that the pressurized Twin Cams oil filter's check valve, which is not used on non-pressurized oil filters, would cause oil to puke out of the carb thru the head vents because the low pressure return-line can't deal with the check valve.

He said just looking at the open end of the filter shows which you have...plastic behind the holes around the top means check valve, no plastic, no valve.

Until that moment I didn't know there was that much difference between my '82 FXRS Shovelhead and '03 Twin Cam RK's oiling system, I just order the best filter for the make/model/year.

Now I can't help but to look thru the top each oil change. ANYWAYS...I'm sure none of us are as lucky to be something so simple, but maybe check it out before you tear too far into it.
Thanks for that info, didn't know any of those facts. My problem turned out to be a small key on the return side
of pump fell into a cavity in the bottom of the pump during assembly. Probably the hardest scenario to fix for my
problem, because the bike was all put together. Thanks to the help of this forum I had all the possibilities mapped
out. Wish it had been an easier fix!!
 

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Discussion Starter #7
Thanks for that info, didn't know any of those facts. My problem turned out to be a small key on the return side
of pump fell into a cavity in the bottom of the pump during assembly. Probably the hardest scenario to fix for my
problem, because the bike was all put together. Thanks to the help of this forum I had all the possibilities mapped
out. Wish it had been an easier fix!!
Ridgidthumper & Thermodyne Thanks, wish you were close to have helped me fix it. I'll never make that mistake
again!
 
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