Oil bubbles in site glass (oil Cavitation)? (goggle search and points to many causes; but nothing specific to Ducs)
Just breaking in a new to me 07 s2r 1K; first thing I did was change oil; but didn't change oil filter; sump screen was cleaned; used a generic 10W 40 4 stroke motorcycle oil. After a spirited ride up a mountain; stopped at idle to check er over; and was surprised to see the oil bubbling in the site glass; doesn't seem normal; have others seen this happen? what would the cause be?
Static bubbles or bubbling away?
Quote from: koko64 on April 22, 2018, 03:24:07 PM
Static bubbles or bubbling away?
at idle... seemed to be bubbling away ... turned off bubbles settles
Do the bubbles have the appearance of something in the oil boiling with engine heat or do the bubbles appear like those caused by aeration/churning?
I would change that filter and drop the oil into a clean container for inspection. What brand oil filter is it?
Any reason to suspect oil contamination? Any unusual engine noise?
Has an engine cleaning (engine flush) additive been recently used?
Sounds like you have too much oil in the crankcase and the crankshaft lobe is whipping it into a froth. Also I've read somewhere higher end oils have anti frothing additives, could be that the generic 10w-40 does not contain any of these.
Where is the oil level? Hopefully that's all it is.
Quote from: koko64 on April 23, 2018, 09:29:16 AM
Do the bubbles have the appearance of something in the oil boiling with engine heat or do the bubbles appear like those caused by aeration/churning?
I would change that filter and drop the oil into a clean container for inspection. What brand oil filter is it?
Any reason to suspect oil contamination? Any unusual engine noise?
Has an engine cleaning (engine flush) additive been recently used?
Back story; This is a fresh rebuild engine new used cases; using original used parts; has a race ecu tuned for termies / open air box; but had to put oem pipes back on; so is running rich for the oem pipes I think; oem pipes are running hot.
Bubbles look like aeration / churning; but oil is just at max on the site widow; so doesn't look overfilled; I'll have to check at lower temps at idle; oil is clean; Max temp I've seen is 220F after uphill load; but even at 190F getting the same bubbles.
Oiler filer looks like a non-oem; crome installed when I bought the case (could be the wrong one?), wanted to run it a bit to flush out contaminants, but maybe I should swap that filter with a fresh one now; just 80 mi on it; Oil is 4 stroke 10 w 40; no engine flush ( no "ho ha snake oil flushing stuff"; is that a good idea?)
Quote from: booger on April 23, 2018, 10:07:08 AM
Sounds like you have too much oil in the crankcase and the crankshaft lobe is whipping it into a froth. Also I've read somewhere higher end oils have anti frothing additives, could be that the generic 10w-40 does not contain any of these.
Oil is 4 stroke motorcycle 10 w 40, maybe not the best, but reputable. Oil is just at max on the site widow; doesn't look overfilled.
Oil at max with bike vertical, or on the stand?
Quote from: koko64 on April 23, 2018, 01:35:49 PM
Where is the oil level? Hopefully that's all it is.
Quote from: ducpainter on April 23, 2018, 02:06:15 PM
Oil at max with bike vertical, or on the stand?
welp ... maybe you guys win; lol.
I did check and recheck; trying to hold the little monster vertical & straight; rear was on a slight incline that the garage floor has; oil looked like it was above the max mark at cold; when I was checking it before was on the side stand idling; ... perhaps churning from the piston ... never seen that before; so was fretting with fresh engine; its a new baby ...lol
Thanks you for your input gentlemen. Enjoy the spring riding (& spring avatars;).
;D