These bikes don’t normally consume oil past the rings or as a result of wear and tear; they simply blow the oil out at the breathers on the heads and suck it through the intake. |
These engines have big pistons and as a result build up pressure in the sump and don’t have very effective sump breathing systems. |
They only work well at low rpm’s. |
Also the higher the revs, the more the oil pressure and as a result, the more the oil moves to the top of the engine. |
When it gets there it needs to go down to the sump again and then it needs to go past the air that is pushing up and outward through two small oil galleries, one on each barrel. |
At this stage the oil and the air work against each other and the oil loses the fight. It ends up living at the top of the engine until the revs drop to normal. |
When the oil has no place to go it goes out of the engine. |
Don’t overfill the oil level as this also causes the oil to blow out. |
If the engine blows the oil out because it was over filled it gets quite messy around the air-filter area. |
We highly recommend that if you have a big capacity engine upgrade that you use Screaming Eagle three in one fully synthetic oil. |
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