- Tue Jan 23, 2018 3:21 pm
#73697
I've said this before but my 350 bullet with the same oil tank breather system produced outrageous quantities of emulsion in the engine all the time. The whole of the inside of the oil tank and the dipstick would be coated with it, the catch can and assosciated hoses would be full of it within a couple of hundred miles.
Even when doing protracted touring (I did an average of 150 miles a day for 3 months) it still filled up with the stuff. In fact, the more miles it did in a day, the worse it got. I replaced the whole lot with a simple 8" long duckbill hose on the oil tank stub and even that would become fully choked with the stuff, it would block and the power would drop and oil would start leaking out round the tappet cover. I'd have to stop and surrepticiously blow it out at the side of the road.
Then one day, I fitted a set of samrat rockers and, because I decided to retain the o-rings and keep them pressure fed rather than volume fed, fitted a hitchcocks scavenge pressure relief valve at the same time. I have never seen a hint of mayo since.
Based on the above anecdote, I'd suggest that those bikes which produce an excess of mayonaise have an issue with the scavenge side going over pressure. How I don't know. Maybe drawing blowpast material into the scavenge pump before it can get to the breather?