Question on a running engine, is it normal for high pressure to be released while opening the filler plug while running? It also released oil mist in the pulsating air. I have also oil that builds up behind vertical cylinder in the cooling fins. I also notice a drop in oil level after a few short rides. I do not see any burning oil smoke though.
Usually not a great idea to take filler cap off while running, oil goes everywhere, engine oil pressure will be somewhere around 20-65psi so just over 1bar - around 4+ bar. If you've oil outside the engine there is probably a leak somewhere. Try and clean it all off and then go for a ride, keep stopping to see if you can see the leak.
OK I will try the riding after washup. I didn't think of the oil pressure on theses, it's my first bike with a pressurized system. I also did a compression test cold and hot they were both und 130psi How else can I determine the health of the engine?
130 isn't a disaster, others with more engine knowledge may be able to give more info. Valve clearance can be a cause of lower pressure if not sealing properly, have they been checked? It's fairly easy to do depending on model. Also damaged gaskets/ seals, that may be your oil leak
Should get a pulsating after removing the cap, 2 pistons going up and down nearly together move a bit of air. If its significant then you might have blow past 130 comp is a bit low. Oil pressure will have no affect on the mist from the hole, any misting around the engine will be a leaking seal or gasket. Or once in a blue moon, a porous casting
I will look into the valves... Do you know how to determine the engine cylinder is at top dead center?
Did you hold the throttle wide open while crankjng for the compression test? Should be done with engine up to running temp so as to have correct tolerances and clearances.
Ducati Monster 750 Dark 11000 km, I bought used three years ago. I think it has more miles but the front tire is from 2000 so maybe it is true mileage. The rear is dated 2005. I do not know any service, it was brought from Lisbon here to São Miguel Azores. This is all I really know. There are no leaks in forks or rear shock, they are very clean. But the engine does have a lot of oil mist. I changed the belts about 1 year ago, about 500 miles ago. I only ride when here on vacation.
Compression is an enigma, as I have asked on here and no one can give a definite answer. You could have a blocked breather pipe/filter from the crank case? Hence pressure from oil filler? Or worn piston rings? Engine mist could be exhaust or condensation? Or something else? A leak down test might help, but this would involve buying a leak down kit and use of a compressor. Criticism's welcome!
I had been but jus realized they were that old.. I was going through the bike to see why I have all the oil mist and oil usage first. May be best for me to give the bike away or sell it cheaply. I don't want to spend any more on it if it needs engine work.
I had innertube failed in one of my old cars , bought replacement, took it to tire shop , they told me that tire was marked year 1975 . Put it back on, no worries
Yes, don’t do it, oil will spray everywhere. It will. Hot oil will splash all over the place. Check the integrity of the crankcase breather valve. It sits just behind the V cylinder on top of the right hand side of the crankcase. It should be connected via a pipe to the airbox. On a bike of your vintage it’s possible the pipe has cracked.
