Can Synthetic Oil Be Used in Old Motorcycles?
The age-old debate about using synthetic oil in older motorcycles often leads to mixed opinions. While some owners swear by it, others hesitate due to potential issues. This article delves into the pros and cons, providing insights for those considering the switch.
Overview of Synthetic Oil
Before we dive into the specifics, it's crucial to understand the basics of synthetic oil. This type of motor oil is designed to provide superior performance and protection, especially under extreme conditions. However, its suitability for older motorcycles remains a topic of discussion.
Why Not Recommend Using Synthetic Oil?
Old Bikes Mineral Oil Compatibility
Many older motorcycles, particularly bikes from the 1970s to early 1990s, are accustomed to mineral oil. The oil systems in these bikes have likely accumulated some debris over the years. Switching to synthetic oil can flush out this debris, which may no longer be stopping leaks. Places with rubber seals are especially susceptible to this issue. As a result, your bike may start leaking oil after the switch.
Why Mineral Oil Remains The Preferred Option
Given these considerations, I typically recommend using mineral oil or a combined mineral-synthetic oil. For my bikes, which date back to the 1970s and early 1990s, I stick to these options because they have performed reliably over the years. Always ensure that the API (American Petroleum Institute) label does not specify “energy conserving”. This designation is common in synthetic oils but can be problematic for older bikes.
Care and Concerns with Synthetic Oil
Functionality and Performance
While some people believe that synthetic oil provides smoother shifting, this may be a placebo effect. In general, synthetic oil should work fine in your old motorcycle. However, clutch slip may be an issue on older bikes.
Compatibility with Two-Stroke Engines
Using synthetic oil with two-stroke engines can pose challenges, as these engines require special care. However, specialized 2-stroke synthetic oils are available and can be suitable if you match the viscosity and ratings to conventional mineral oil. Some users have experienced seal leaks, but I have not faced this issue. Synthetic oil has been particularly effective for air-cooled motorcycles, and I have successfully used it in my '83 Honda and '06 Harley.
Engine Protection and Oil Pressure
One notable downside is that synthetic oil may lead to an increased risk of oil pressure issues, especially in older engines. I have a personal anecdote to share. In 1998, I owned a 1998 Yamaha V-max, and after changing to fully synthetic oil, the oil pressure warning light came on. Within 100 miles, the oil sump was nearly half empty. The older engine could not handle the synthetic oil's tolerance levels, and the oil blew past the pistons and out the exhaust pipes. I quickly reverted to the original oil specification. This experience highlights the importance of sticking to established oil guidelines for older engines.
Conclusion
In summary, while synthetic oil can provide exceptional engine protection, its use in older motorcycles comes with certain risks. Always research and consult with experts before making any changes to your motorcycle's oil regimen. If you encounter issues, it's best to switch back to traditional mineral oil, which will ensure the proper functioning of your bike.
FAQs
Q: Can I use synthetic oil in my old motorcycle?
A: While it might not be ideal for all bikes, it can be used in certain circumstances. Ensure you match the viscosity and ratings with conventional oils, and consider the age and condition of your motorcycle.
Q: Are there risks associated with using synthetic oil?
A: Yes, synthetic oil can flush out debris, leading to potential oil leaks. It may also cause oil pressure issues in older engines. Always ensure you are using the appropriate oil for your specific make and model.