oil in the air filter box
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Blrry
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A broken piston oil ring? It depends on how much oil you're talking about. A crankcase breather allows the blow by (the exhaust gases that squeak past the piston rings into the crank case), kind of like a PCV valve is my understanding, to de-pressurize the crankcase, returns the combustion gasses to the air intake. Oil mist will accumulate in the box sometimes via this method. Check to see if your oil level is too full, check compression in each piston. That's about all I can think of doing.
Of course, I'm not a "real" mechanic... but that's what I've seen from my other bikes that I've worked on...
Of course, I'm not a "real" mechanic... but that's what I've seen from my other bikes that I've worked on...
The questions that needs to be ask is how many miles are on the bike, is the oil over full, and do you wheelie the bike often?
If it's got high miles on it the rings could just be getting worn allowing some of the combustion to bypass the rings, and pressurize the crankcase, pushing oil through the breather.
If the oil isn't grossly overfilled a combination of high oil level and worn rings could do it as well.
Lastly if your doing a ton of wheelies oil will splash to the back of the crankcase and get pulled in to the engine on real tall wheelies.
Is it soaked or just a little spot? A little spot isn't really a big deal.
If it's got high miles on it the rings could just be getting worn allowing some of the combustion to bypass the rings, and pressurize the crankcase, pushing oil through the breather.
If the oil isn't grossly overfilled a combination of high oil level and worn rings could do it as well.
Lastly if your doing a ton of wheelies oil will splash to the back of the crankcase and get pulled in to the engine on real tall wheelies.
Is it soaked or just a little spot? A little spot isn't really a big deal.
There is 18000 km about 11000 miles. I am the second owner and never on the rear wheel. and the previous owner bought the bike when he was 49 years old, so I am skeptical about him doing wheelies lol. there was about 1/2 an ounce in the box and I think the air filter absorbed about the same amount. oil level is right on the mark.
Yes. The length shouldn't matter. There should be several small drain bulbs under the air box to trap moisture or oil. Keep an eye on them and remove and drain as needed.
Download the free service manual. I don't know the spec or wait for one of the mechs to answer up. I think valve adjustment could play into this too but I doubt it with 11K miles.
Telboy2000
Registered
its quite normal....especially on bikes that do shortish runs in cool climates with low rpm and don't get hot enough to get the oil vapours thin enough to pass through the plastic gauze and be drawn into the throttle bodies.
The oil vapours condense too soon so rather than being sucked in as vapour it forms as oil on any cold surface etc.
The oil vapours condense too soon so rather than being sucked in as vapour it forms as oil on any cold surface etc.
Thank you Telboy2000, I will check that out and thank you to all who answered. As a new owner, I appreciate all advice that is offered.
The length of the adapter that threads into the spark plug hole for the compression tester does matter. For accurate readings you need to fill the spark plug hole to the same depth as the spark plug. Anything less increases the volumes of the combustion chamber and will lower your readings. However, the uniformity of the readings (assuming they are not ridiculously low) is more improtant than the absolute value of the individual readings. Compression tester gauges are notorious for being widely different from gauge manufacturer to manufacturer. Make sure you have a charged battery, hold the throttle wide open and crank the engine over many times until you get a stable reading. I normally do this on a cold engine and them again on the engine at operating temp.. Watch the gauge while you are cranking the engine, the pressure should not drop between strokes or else in means the check valve in the gauge is leaking and your readings will be inaccurate. When you put the spark plugs back in, put a little antisieze compound on the threads and use a torque wrench to tighten them.
A compression test is an OK method to get a quick indication of the health of the rings and valves. A better way is to use a leak down test. The leak down test applies compressed air to the combustion chamber and tells you the percentage of leaking you have across the piston rings and valves. It allows you to listen for the source of the leak.
What weight oil are you using? How did the spark plugs look when you removed them, brown color and dry or black and wet? What kind of riding have you been doing, lot's of WOT runs, lots of extended high RPMs or cruising? A small amount of oil ( oil film in the area right around the crankcase hose connection) is normal. Keep an eye on you oil consumption over many miles (1000 miles minimum), that will tell you if you have problem or not without looking inside the airbox for oil.
Jim
A compression test is an OK method to get a quick indication of the health of the rings and valves. A better way is to use a leak down test. The leak down test applies compressed air to the combustion chamber and tells you the percentage of leaking you have across the piston rings and valves. It allows you to listen for the source of the leak.
What weight oil are you using? How did the spark plugs look when you removed them, brown color and dry or black and wet? What kind of riding have you been doing, lot's of WOT runs, lots of extended high RPMs or cruising? A small amount of oil ( oil film in the area right around the crankcase hose connection) is normal. Keep an eye on you oil consumption over many miles (1000 miles minimum), that will tell you if you have problem or not without looking inside the airbox for oil.
Jim
I bet one dollar previous owner took out the K&N filter he had in there and put back the oem one.
I'd also guess he may have sprayed a tad bit too much on it last time he cleaned it.
If the oil in the box is red.......winner winner chicken dinner.
I'd also guess he may have sprayed a tad bit too much on it last time he cleaned it.
If the oil in the box is red.......winner winner chicken dinner.
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