I need to replace my oil lines from my oil bag to oil pump and filter on my
Evo motor. By removing and replacing these lines will this cause any problems with the oil pump.
I heard years ago you could lose the prime on the oil pump, is this
true? Hopefully you guru's can help me out on this. Also what is the
best size oil hose to use? Thanks in advance.

 

I can only speak from my experience. I changed all my oil lines years ago and had no problem with the pump picking up the prime

 

The pump on a softail is gravity fed..no way to lose "prime". I could see that happening on the bikes the have the oil tank under the trans.