M0T0Geezer
Cruisin' Guzzisti
I have a 2004 Breva 750. Starting to get oil seepage/weepage along the engine to bell housing joint. More oil coming out the weep hold in the bottom of the bell housing. Beginning to think this is [yet] another symptom of engine oil overfill (but I carefully try to avoid that). I think there is pressure building up in the engine (blow-by?) that is forcing the oil out. Shown below is after about an hour's run:
Diagrams from the Parts and Shop Manuals do not directly map how blow-by pressure is getting dissipated. Only the oil vapor tubes from each valve cover into the Air Box are shown as possible vents. How does blow-by pressure get into the valve covers? Up the pushrod galleys?
I verified that the non-return valve is working properly (i.e., only allowing flow of air and oil from the Air Box and back to the crankcase oil pool). This could only happen when there is greater vacuum (negative pressure) in the crankcase than the vacuum present in the Air Box. When would/could there ever be more vacuum in the crankcase than in the Air Box? How (and where) is positive pressure in the crankcase relieved?
Basically, the Crankcase Breather seems to only be able to suck - never blow. Anyone here have intimate knowledge of the actual oil pathways - vapor and liquid - in the '04 Breva 750 motor?
Thanks for sharing your info - 'Geezer
Diagrams from the Parts and Shop Manuals do not directly map how blow-by pressure is getting dissipated. Only the oil vapor tubes from each valve cover into the Air Box are shown as possible vents. How does blow-by pressure get into the valve covers? Up the pushrod galleys?
I verified that the non-return valve is working properly (i.e., only allowing flow of air and oil from the Air Box and back to the crankcase oil pool). This could only happen when there is greater vacuum (negative pressure) in the crankcase than the vacuum present in the Air Box. When would/could there ever be more vacuum in the crankcase than in the Air Box? How (and where) is positive pressure in the crankcase relieved?
Basically, the Crankcase Breather seems to only be able to suck - never blow. Anyone here have intimate knowledge of the actual oil pathways - vapor and liquid - in the '04 Breva 750 motor?
Thanks for sharing your info - 'Geezer