I recently purchased a Honda ST 1100 with 58,000 miles. The previous owner used synthetics since the bike had about 5000 miles. I've always been under the impression that you can't switch back to a mineral based oil once you've run a synthetic in your engine. Is that a myth or fact? Thanj you in advance for your insights.

Switching back? (Even you wrote that word) It sounds me like going back to use a coach (as preferred way of transportation). But, all of us have their reasons, preferables, ... Could you explain me (us, actually) what argumentation is your consideration based on.
Direct answer is: you , definitely have been under influence of myth!
If you want to miss all synthetic oil advantages and decide to use petroleum oils in your Honda you can do it without any special precautions. Regarding that synthetic oils are compatible with petroleum ones switching procedure is very simple. You do not need even to flush engine (like it is recommended with opposite switch). Just pour in oil and - that's it. Everything else, like filter change, flushing, ... is optional.

BTW, my personal advice would be do not switch back, make a good choice among synthetic oils.

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Thanks for the reply. Glad to hear its a myth. BTW...I'm not planning to switch back. Do you think its OK to go 6,000 miles between oil changes if I change out the filter at 3,000 miles?

Yep, the engine is not that smart to know if the oil is synthetic or dino juice.

No more than your liver knows if you are drinking Miller Lite or Bud Light> LOL

Originally posted by Djordan:
I can just suggest you use of Amsoil 10W-40 High Performance Motorcycle Engine Oil (AMF) or (if supplies are spent) 10W-40 Synthetic Motorcycle Oil (MCF). The last one oil is newer product. That viscosity is primarily used by Japanese manufacturers.

Service life: for “on road” use in engines and transmissions, change AMSOIL MCF and AMSOIL engine oil filter at twice the motorcycle manufacturer change interval or one year, whichever comes first. Change of other brand oil filters should be at standard intervals.

For “off road” use in engines and transmissions, change AMSOIL MCF at the standard motorcycle manufacturer's change interval.

Recommended (Amsoil) oil filter is: SMF 103.

For all additional info you can e-mail me at: gordan_d@yahoo.com

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