Can't find oil leak 98 sportster

[LawnDart]

Both 720 engines have oil on the bottom and on the engine plates. Since I sealed the tank grommet and lines from the tank appear dry, I don't think that's where it is coming from. The small lines for the rotary valve bath intact and dry. The large lines appear OK but it's difficult to tell as they are somewhat oily but not outright wet like the bottom of the engines.

Could it be coming from the engine itself? Any tips or experiences on chasing oil leaks?

 

[XP 787]

Still running oil injection? One of my oil lines had a small crack in it where it went to the oil pump (the bigger feed line). Make sure your tiny oil lines going to the rotary cover are not cracked also.

 

[LawnDart]

I managed to pull (it was difficult to get to) the large line on the bottom of the port engine, thinking like you said it would have a crack near the fitting. But it didn't and looked good back to the T. I trimmed it a bit and reconnected it just to be sure. All of the small lines appeared to be dry and not cracked. They were clear and I could see the red oil and no air, though I may change them just to be safe.

At this point I'm baffled......

 

[XP 787]

Check the oil lines going to the crankcase for the rotary bath. One should be a feed and the other a return.

 

[rockstar342]

Had the same problem with mine. Checked everything. Ended up being the rubber seal between the oil pump flange and the rotary valve cover. Part #420850160. Hope this helps.

 

[LawnDart]

Had the same problem with mine. Checked everything. Ended up being the rubber seal between the oil pump flange and the rotary valve cover. Part #420850160. Hope this helps.

Yes thank you! I take it you remove the oil pump to replace it?

 

[LawnDart]

Update.....I replaced the oil lines and triple checked the tank....all good there. The oil feels like its coming from the oil pump or the bottom fitting.

 

[rockstar342]

Correct. Oil lubes the rotary gear and seal wears over time and will leak.