Bare with me as I am a novice.

I just came upon a 1974 Sportster that hasn't ran in a year.

Looking from the back of the bike I have an oil leak from the left side engine cover when the bike is running. There appears to be two plugs which will dribble/spit a considerable amount of oil. One of the plugs which is closer to the front of the bike has a straight slot with a vent hole while the other has a cross. There is no oil leaking from the breather tube.

Thanks for your help.

P.S. I have ordered a shop manual, it just hasn't arrived yet

 

Motor oil can run into the primary, overfilling it. Prop the bike upright and pull the level screw plug in the primary chain case and leave it out till no more oil runs out. That's the proper level for the primary and tranny. I've run more than a quart out on some old ironheads that have sat for a long time with out running.

Note, make sure it is the level plug and NOT the drain plug.

 

are you looking to buy this bike? I wouldn't recommend an iron head ot a novice mechanic. lol I may have just had bad luck with mine, but I really was working on it all the time!

i would say those plugs are missing the oring seals on them, or they are cracked and leaking.

 

+2

 

Thank you for the fast reply guys!

I was told it could be the pince washers behind the plugs, which I am going to replace.

In the case that there is too much oil in the primary, which plug is the level plug and which is the drain plug?

Thank you for your patience, although I am not a motorcycle mechanic I do own a HVAC/R biz dealing with reciprocating compressors and am fairly mechanically inclined. I just don’t know the sequence of operation, location, and proper terminology…yet.

Again thanks for the help guys!

Danny

 

Replace the orings as was recommended above. While you're at it, replace the primary fluid and let the extra oil drain out of that little screw (with the bike level).

Replacing cracked, worn, dryrotted seals and o rings is a way of life on these old dinosaurs.

 

The drain plug would be at the lowest level of the chain case, the fluid level plug will be ahead of the footpeg about 2"- 3" and is out the side not the bottom.