If a motorcycle clutch starts slipping after an oil change, it could be due to a few possible reasons:
Incompatible oil: The most common cause of clutch slipping after an oil change is using an oil that is not compatible with the motorcycle's wet clutch system. Some oils, particularly those designed for car engines, contain friction modifiers that can cause excessive slip in a motorcycle's wet clutch. These additives are intended to improve fuel efficiency but can negatively affect the clutch's performance. To resolve this issue, it is important to use motorcycle-specific oil that is formulated to work with wet clutches.
Incorrect oil viscosity: Using an oil with an incorrect viscosity or grade can also lead to clutch slipping. Motorcycle engines have specific requirements for oil viscosity to ensure proper lubrication and clutch operation. If the oil used is too thin or has a lower viscosity than recommended, it may not provide enough friction to engage the clutch effectively, resulting in slipping. Consult the motorcycle's owner's manual or manufacturer recommendations to ensure the correct oil viscosity is used.
Contaminated clutch plates: During an oil change, if contaminants such as dirt, debris, or old clutch material find their way into the clutch assembly, it can lead to clutch slipping. These contaminants can interfere with the clutch plates' ability to engage properly, resulting in slippage. It is essential to ensure a clean and proper installation of the clutch plates during an oil change.
Clutch wear: In some cases, clutch slipping after an oil change may not be directly related to the oil itself but rather an indication of an underlying clutch wear issue. Over time, the clutch plates can wear down, losing their friction material and causing them to slip. The oil change may have coincided with the clutch reaching its wear limit, and the slipping becomes apparent afterward. In such cases, a clutch replacement or adjustment may be necessary.
If you are experiencing clutch slipping after an oil change, it is recommended to consult with a qualified motorcycle mechanic or service professional. They can diagnose the issue more accurately, determine the cause of the slipping, and perform any necessary repairs or adjustments to ensure proper clutch operation.