1983 FLH 4 speed belt drive oil lines?

[pancho]

Howdy hope all are well. Question on my 83flh oil lines
the 3/8th id 5/8th od oil lines seem to be more than needed but I believe that’s factory correct. Would make more sense to be 5/16th id and 9/16th od as all nipples and oil bottle bungs are 1/4 id. The 5/8th od is very tight fitting in between the transmission plate and horizontal support plate. Also would make routing all the lines a bit easier to work with. Working on making this bike factory correct as possible as I have kept all the oem parts when I bought this bike 31 years ago. Thanks for any replies.
Pancho

[joe fxs fxr]

Even though the fittings are 1/4 ID, they are very short compared to the oil lines. 3/8 ID is a lot less restrictive than 5/16 ID hose and I recommend you stick with the factory size. A lot of people, including me, use automatic transmission oil cooler hose because it is designed for hot oil. That is even bigger, 11/16 OD, but it fits.

[pancho]

Thank you Joe for the quick reply. I kinda thought that was factory size. Bike has been sitting comfortably for 21 years. I have others. Now in Florida I figured I’d make a project out of it and get it back the way it was when I bought it in 93. Put drag pipes, mustang seat, bdl belt primary drive, basic windshield. But again kept all the original parts and now it’s gonna go back. As far as I know it’s an original machine. I’m the 3rd owner. Original paint and all sheet metal, wheels and brakes. Back in the day we threw all the “garbage” away but did build wrench and ride them choppers. In 93 at the ripe old age of 41 I knew not to do that to this bike. Thanks again for your support.
Pancho

[duffeycycles]

I agree with Joe & there is high pressure transmission hose that looks better & does not kink like cheap lower pressure hose does.

[vph-d]

I believe modern fuel line is designed for the high pressure needed for fuel injection systems. The early 65 Pans had a 5/16 vent line that was changed to 3/8 before too long, don't reduce the size of your oil lines.
vph-d

[duffeycycles]

Fuel hose is different than transmission oil cooler hose.There is high pressure [400psi] & regular pressure transmission hose.Don't use fuel hose for oil hose.

IMG_1368.JPG

[otis71]

What is the issue with high pressure fuel line for oil? Not being contrary, trying to learn something I didn’t know. Thanks

[joe fxs fxr]

What is the issue with high pressure fuel line for oil? Not being contrary, trying to learn something I didn’t know. Thanks

Gas line isn't designed for high temperatures. There may be other differences, but that's one for sure.