Randall Washington, aka "Randakk"
President and Chief Executive Rider
Chapel Hill, NC USA
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Return to main Tech Tips Index Another Reason to Change your Oil!My Grandfather changed the oil in his car once a month. He greased the chassis lube points on the same frequency. He always said that oil and grease were cheap insurance compared to engine repairs. Grandpa was mainly right.
But these days we have heightened awareness of "green" issues and must balance environmental concerns against the real need to protect our engines via proper oil changes. Modern automobiles incorporate sophisticated engineering refinements such as ultra precise tolerances, advanced piston ring design and clever control of crankcase ventilation that help extend oil change intervals with minimal risk. Vintage motorcycles do not enjoy such engineering. Time tested advice: change your oil every 4 months or every 3000 miles whichever comes first. Yes, this might seem a bit overly-frequent. However, if you follow this regimen, you will never have an oil-related failure and your engine should be good for at least 250,000 miles. In my own bikes, I treat them to several oil/filter changes per year regardless of miles accumulated (typically not too many). Main Reasons to Change Oil 1. Oil and the additives in oil gradually break down during use through thermal and mechanical action. Degradation at the molecular level reduces lubricating effectiveness. Also, the significant shearing forces generated in a motorcycle with a "shared" engine / transmission oil sump along with a "wet" clutch accelerate this effect compared to modern cars. 2. Oil's ability to maintain proper vicosity-to-temperature calibration diminishes as the oil gets "tired." 3. Byproducts of combustion sneak past the piston rings and begin to dilute and contaminate the oil. Ditto for imperfectly sealed coolant passages which can allow coolant to infiltrate the crankcase. 4. Microscopic coke particles accumulate in the oil. This is the main explanation for why oil darkens with use. 5. In any running engine, moving parts shed metallic particles. These microscopic particles circulate in the oil and grind against moving part surfaces causing wear. The oil filter removes a high volume of these particles, but eventually the oil filter can become overwhelmed. 6. Neglected oil inevitably breaks down over time and begins to oxidize. That's a bad development as the additives will separate, morph and solidify. This forms one of your engine's worst enemies: sludge. For these reasons, the oil and filter need to be changed on a regular, religious basis. The purpose of this Tech Tip is to call your attention to a less well known reason the change your oil. As oil ages past its useful service life, harmful acids and other "nasties" build in the oil. These acids have been implicated in stator failures in vintage motorcycles.
Our motorcycles don't have external auto-type alternators. Instead, vintage Hondas have fixed, internal stators that typically live in a "wet" environment...constantly splashed by engine oil. This is a good design in that the oil splash helps keep the stator windings cool, but worn out motor oil is thought by some to be a contributing factor in premature stator failure. It is thought that the acids can deteriorate the thin, insulating coatings on the windings causing them to fail and produce open circuits, short circuits and inappropriate short circuits to ground. Any of these problems can take out one or more phases of your stator. Stator replacement on an early 'Wing requires engine removal and partial engine disassembly. It's a very time-consuming task and very expensive if you're paying for someone else's labor. Do yourself and your bike a favor: keep fresh oil in your bike! Type of Oil to use? Oil recommendations are inherently controversial. If you change your oil often (as you should) most modern oils are OK. Generally - any fresh oil is better than the most expensive oil past its useful life! You can't go wrong with Honda, Kawasaki, Suzuki, Yamaha or other brand of motorcycle-specific, conventional motor oil. The recommended viscosity is 10W-40. Do NOT use modern automotive oil - friction modifiers added to improve gas mileage make it is too slippery and may cause problems with your wet clutch. I don't recommend synthetic oil or synthetic blends because they are not necessary. Universal Oils? If you insist on using oil that is not spec'd for motorcycles, a very good choice is conventional Shell Rotella-T (15W-40).
Shell Rotella-T Conventional Motor Oil This is a so-called "universal oil" which is primarily marketed for diesel use. This oil has high pressure zinc and phosphorus additives which are beneficial to the transmission gears which share the crankcase oil. It does not have any harmful friction modifiers that can harm a wet clutch. Note that not all diesel oils are classified as "universal oil." Shell Rotella-T (conventional 15W-40 grade) also meets the strict standards issued by the Japanese Automotive Standards Organization for motorcycle usage (JASO-MA). Shell Rotella-T is available at most mass merchandisers (like Wal-Mart) at a very attractive price. This is the oil I use in all my bikes these days. When you change your oil, be sure to recycle the old oil in a responsible fashion. Return to main Tech Tips Index Intellectual Property Notice: All material appearing in this website is the property of Randall Washington, and is protected under United States and international copyright laws. The photographs, text and other content may not be copied, reproduced, distributed, stored, or manipulated in any manner without the express written permission of Randall Washington. For more information on the use of material from this website, click here |
