Greetings,
After two years in storage I have started working on my 79 XLH again. While running it just long enough to warm it up I did observe oil returning to the tank, oil light went out, the generator light did not, different story, waiting on parts.
I was running 70 weight because that is as close to the manual as I could get at the time. Manual says 75. Having forgotten this, I referred to the forum and followed the suggestion to use 50 weight. For the first time after the change, I lost prime and have no return flow. I followed the manual, pulled the pressure switch, got oil pumping thru thu pump, but very little pressure and no return to tank.
I can dump the new 50 weight and install 70 and try again but i am wondering if anyone thinks a kit would help? I somehow doubt it. A new pump is +400.00 and it wasn’t broke till I fixed it.
Any thoughts,
Sorry so long!

 

i doubt seriously the oil weight has anything to do wit it.
the book says to remove the inlet to the pump to expel any air, NEVER did it to mine since new august 1974.
if you have the manual, look closely how the sender switch is tied in. if there is any oil in the galleries, that could drain back giving a false positive.
oil back to the tank will not be steady and if on the stand, takes a lot of oil to fill the case to get to the scavenge side of the pump. oil pressure is 3>7psig idle and maybe 15 at speed. that switch hole is tiney-tiny so for grins and giggles, remove the adapter and see if oil is draining through the pump (not running), would be funny though. while off, look at the ball and spring.

 

I agree on oil 50 vs 70 making a big difference, especially cold, but this the only thing changed. The auto store on the way home did not have anything over 30 so a mute point. Not sure what adapter and spring you are referring to?
I will try again tomorrow. This is the first time I have ever had an airlock, thanks for the help, old motorcycle are like old women........

 

oops my bad missed the year.
are you talking harley oil grades or sae grades, big diff.

 

nowhere in the manual does it call for 70Wt engine oil

 

70 weight seems a bit over the top. I have 20/50 for the cold months and short trips, in my 72. 50w goes in during the spring and summer.

 

+1

 

As a former 1979 owner, I had this happen to me once. Long embarrassing story caused by a teenage dumb *** (me) who didn't know what he was doing. But I was able to fix it.

My wrench told me to removed the timing plug and pump some oil in there, same grade. Somehow that got enough oil back to the pump to get her going again. This was 30 years ago, yeh your results my vary. Good luck, seriously with that '79.