Oil leak out of breather since nose cone replacement
I have had this bike for years. I have done all the mechanics on it including top and rebuild several years back. I had a nose cone bushing go bad so I replace the nose cone with a good quality one. When I went to fire it up it kept puking oil out of the breather. I would add oil and it would continue puking it out. It seemed like it would puke less when revved up versus when it was a lower RPM. I took the old pump apart. The keys and everything were good. There was some scoring in the cavity. I have the breather timing set correctly. What could be causing this problem? This problem did not occur until I replace the nose cone. Could be coincidental
I have had this bike for years. I have done all the mechanics on it including top and rebuild several years back. I had a nose cone bushing go bad so I replace the nose cone with a good quality one. When I went to fire it up it kept puking oil out of the breather. I would add oil and it would continue puking it out. It seemed like it would puke less when revved up versus when it was a lower RPM. I took the old pump apart. The keys and everything were good. There was some scoring in the cavity. I have the breather timing set correctly. What could be causing this problem? This problem did not occur until I replace the nose cone. Could be coincidental
Not coincidental, scoring in the breather cavity will cause your issue. Is your breather plastic or metal? I ask because if it is plastic it is possible that the gear has snapped of and the breather is not rotating. Been there, this will cause your bike to puke oil continuously. Although my gear did snap, fortunately my cavity was not scored and I replaced it with a S&S metal breather. The concept of the plastic breather didn't work out so well in SOME instances where small pieces metal found it's way into the breather and became embedded into the plastic. In theory the gear would snap but sometimes the breather became a rotating grinding wheel, scoring the cavity which required splitting the cases to fix until S&S came up with the oversized breather and reaming tool.
did you remove the breather valve or did it fall out when the cover came off?.. sometimes they come out when the cam cover comes out & as you say it must be timmed when put back together, if you didnt get it right it's probably out of time so pressure builds up in the cases puking oil everywhere......... just an idea......plus there are at least two nose cones depending if end or side oiler, are ya 100% that you fitted the same that came off,... not sure what that would do other than getting no oil to the crank, but it might pressurise the cases, never made that error but it can happen....
Last edited by magnum45pete; 02-18-2022 at 07:42 AM.
I will check the breather. I actually had it out and made sure everything was timed properly. I believe it is a metal breather. The scoring was actually in the oil pump cavity. I don’t see a very steady stream on the return line in the tank when it idle. And when revved up it kind of percolate like it’s getting air. Plan on replacing the oil pump, it just seems weird that it happened when I had the nose cone off. I’m just making sure that something else may not of happened. The timing marks are lined up. That can anybody tell me the breather screen location in the opening of the block when the timing marks are aligned .
Last edited by Rsmith3065; 02-18-2022 at 07:46 AM.
the oil pump shouldnt effect crank case pressure it just handels oil in & oil out.... did you check the breather shim, if forgotten the breather could move in & out maybe up t a 1/4 & that might effect it, again I've never done that but could be worth checking
return at idle does pulse, smoothes out with revs, but a pump shouldnt have any effect on crank pressure...
I will check that. I don’t know the history on this bike. I have read that if this thing has had any kind of modification then the breather would have to be timed to the engine differently. Is this correct? When it’s coming out it’s almost like a steady stream.
I have had this bike for years. I have done all the mechanics on it including top and rebuild several years back. I had a nose cone bushing go bad so I replace the nose cone with a good quality one. When I went to fire it up it kept puking oil out of the breather. I would add oil and it would continue puking it out. It seemed like it would puke less when revved up versus when it was a lower RPM. I took the old pump apart. The keys and everything were good. There was some scoring in the cavity. I have the breather timing set correctly. What could be causing this problem? This problem did not occur until I replace the nose cone. Could be coincidental
You may have either the wrong cover or the wrong cover gasket. Evo and Shovelhead covers look the same, mount the same but have internal differences because of the whole head breather/case breather thing.
Well it is supposed to be. I did compare the new one to the old one and they look identical unless there is something internal that I can’t see. At first I didn’t notice the wrong gasket was on it because the one small hole was covered but I have since corrected that.
You haven't mentioned the year of the engine. Did you remove/disassemble the pump during the cam cover change or after?
Oil moves from the cam chest to the breather/separation cavity and then to the oil pump return. (pardon my bad art work) If the journal between the oil pump return and that cavity is restricted that'll cause a problem.
The tube for the crankcase vent is high in that cavity, so it'd have to have oil all the way up there to "pump" it out the breather hose.
02-18-2022 | 06:53 AM
Oil leak out of breather since nose cone replacement
