What causes blow-by in a Harley Davidson?

What causes blow-by in a Harley Davidson?

The reality, however, is that this oil can sometimes build up faster than the motor can suck it in. As a result, the excess oil buildup drains to the bottom of the air cleaner assembly via gravity, and drips out onto the engine and everywhere else the wind blows it while you ride.

What causes a Harley Davidson to blow by oil?

Excessive blow by is caused by any number of symptoms as Dave described . Normal blow by is only an issue when the blow by accumulates into puddles of oil and makes a mess all over the chrome and pants leg !

What to do when oil comes out of air cleaner on Harley Davidson?

On a stock Harley-Davidson motorcycle, the oil will come out of the air cleaner. To fix the wet sumping problem on your bike, replace the check valve in the oil pump, or replace the whole oil pump.

Where does the oil come from in a Harley Davidson?

Top breathing engines breath, or vent, through the top breather bolts which are threaded into the heads of a Harley Davidson motor. The air inside a motor is saturated with oil. It exits through the breather bolts and into the airbox where the air is filtered and the oil is captured in the air filter.

What to do about wet sumping on a Harley?

On a stock Harley-Davidson motorcycle, the oil will come out of the air cleaner. To fix the wet sumping problem on your bike, replace the check valve in the oil pump, or replace the whole oil pump. If you start your engine every week, your Harley won’t wet sump unless the oil pump check valve is bad.

What causes oil sumping on a Harley Davidson?

Oil has sumped into the bottom of your crankcase and is blowing out of the breather line. This is typical after a bottom breathing bike sits for a prolonged period of time. If the bike has not been sitting and this is happening, we would suggest inspecting your oil pump.

Where do you put the oil in a Harley Davidson?

Below the flywheels locate the breather hose and put it into a 2 liter soda bottle. Start the m/c and let it pump itself out approx. 1 to 1 ½ qts depending on how long the m/c sat and sumped. If you use a clean bottle, you can put the oil back into the tank.

What can cause 1989 Harley pukes oil out crankcase vent?

Re: 1989 harley pukes oil out crankcase vent when started… Blow by compression. Severe engine problems. Pull the heads look at cylinder walls You can’t post conmments that contain an email address. I have 1983 Harley Sportster 1000 that won’t fire when I first turn the key, but after a few minutes it fires right up what can cause this?

What makes an oil sump on a Softail?

On older, bottom breathing motors (pre 96) sumped oil would also pump out of the bottom breathing vent and onto the ground. Softail models and older FX models are more likely to sump because of the high oil tank location. Gravity comes more into play. Touring models have an oil pan, in a low position, beneath the transmission.