Oil Pump Spring

[1970 XLCH]

Had problems with hydraulic tappets pumping up on my '71 FLH . I've changed pressure relief spring 26207-73a with 20207-83 . It solved the problem . I am concerned with the bottom end getting enough oil . Anyone have any experience with this ?

[aumick10]

1970 XLCH,
The 71-73 shovel motors had an oil system that was prone to over oiling the bottom end and starving the top end. To fix this they added a second circuit to seperate the top and bottom end oil systems. The tappets and top end got the oil first. As pressure rose in the oil pump, it was then sent to the bottom end.
A roller bearing bottom end doesn't need much oil, nothing like a slipper bearing.
S&S have a very good instruction sheet on how to modify the 71-73 cases to update them. A very recommended update.

[1970 XLCH]

Just an update of the never ending saga of my 1971 FLH !! I followed the recommendations on this forum to upgrade to an S&S oil pump .
I bought the kit # 31-6294 . I drilled & plugged the cases as per the instructions .
Took it out for a test ride and it ran well but at an idle it SMOKES LIKE CRAZY !!! ( white smoke , oil ) .
Pulled the pipes there was oil on the rear exhaust guide ( yes it has valve seals ) .
I put a smaller orifice oil fitting in the rear rocker box ( .093 ) , still smokes !!
I put a smaller ( .063 ) orifice in , still smokes !!
Put a weaker relief valve spring in ( -73A ) S&S comes with a -83 spring , still smokes !!
I am ready to plug the new case holes & put the old pump ( NO SMOKING WITH THE ORIGINAL PUMP !! ) back on & run solid lifters ( the start of this whole thing was because my S&S lifters would loose their hydraulics at idle & rattle ) .
HELP !!!

[aumick10]

I can feel your frustration.
Did you end up replacing the pinion bush for an end oiler bush? If not, you may now be getting too much oil to the top end.
I assume you did all the necessary steps in the instructions. Steps 1,2,3,5,6,7,8,9.

[1970 XLCH]

Thanks aumick10
Yes I did everything !! I read the directions at least 6 times , they are pretty confusing at first .
New end oiler bushing . plugged the vent hole at the bottom of the pinion shaft bore . Bought the S&S fixture to drill the cases.
It's just pumping too much oil to the top end .

[aumick10]

It is a fairly major surgery to a set of cases, and there is a lot of steps. But it is a worthwhile modification.
The oil line fitting to the top end are two different sizes internally. I can't remember which is which, but I wouldn't have thought they would make much difference. I think the smaller bore fittings go to the top end and the larger ones go between the rocker boxes.
How long did you run it. There may be too much oil in the bottom end. Is the new anti drain valve in the new pump sealing.
I have never plugged the "vent hole " before, I though the end oiler bush blocked it off.

[1970 XLCH]

I have run it a few different times , a total of 50 miles .
I don't know about an anti drain valve . Are you talking about ball valve ? I think so . it is working ,there is no wet sumping going on .
There is a service bulletin for later model shovels ( around '81 ) to decrease the ID size of the upper oil fitting to the rocker box to .093 ( pt # 63543-82 )
The vent hole on 70 to 72 cones have a vent hole ( pic in prior thread ) that the S&S instructions say to plug , along with replacing the bushing . No the bushing doesn't cover it .

[1970 XLCH]

Once again , it only smokes at idle , when you rev it the smoke goes away . Which makes me think it has something to do with the relief valve.

[aumick10]

The ball valve is an anti drain valve.
Sounds like you have done everything correct.
Not something stupid like the carb?

[1970 XLCH]

Runs great ! Just embarrassing at a stop light . Maybe someone else has had this problem out there ???

[T. Cotten]

I gotta ask, 1970 XLCH,

Is it white 'smoke' in cool weather?

Can you smell it?

....Cotten

[1970 XLCH]

Thanks Cotten ,
Yes , white smoke . 60 degrees . No smoke at all before changing the pump .

[T. Cotten]

Its often just water vapor, 1970!

Does it smell like oil, or like fuel?

....Cotten

[1970 XLCH]

Definitely OIL !! Smells like it . You could kill mosquitoes with it !!

[T. Cotten]

Definitely OIL !! Smells like it . You could kill mosquitoes with it !!

Ouch.

You might pull the manifold and feel for oil on the valve stems. If they are wet, you're flooding the top end.

....Cotten