I've used Castrol Stntec 20/50 in all three holes over five years time for 117,000 miles without any viscosity issues

 

Absolutely not true. All CVO bikes still come with Syn3 in all 3 holes. Harley-Davidson suggests Syn3 as a recommended replacement to the conventional 20w50 motor oil. The last bulletin Harley sent out for Syn3 was this: http://www.google.com/url?sa=t&sourc...F-gkLg&cad=rja. When Harley actually approved the use of Syn3 in all of their motorcycles.

Go to http://www.harley-davidson.com/pna/p...bmLocale=en_US and any other questions will be answered.

 

Thats not correct.

Here is the Syn 3 info off the HD Website today

Screamin' Eagle® SYN3® Full Synthetic Motorcycle Lubricant - SAE 20W50


TESTED-CERTIFIED for use in Harley-Davidson® engine, primary chaincase and transmission applications, Screamin' Eagle® SYN3® Full Synthetic Lubricant makes changing and topping-off fluids a simple one-product process. Developed with a proprietary three synthetic basestock formula, Screamin' Eagle® SYN3® Lubricant is formulated to provide for long-term protection and engine cleanliness requirements, and to provide superior high-temperature protection for high-output engines. SYN3® Lubricant is formulated to maintain the coefficient of friction for proper clutch operation and to provide the proper lubrication to the primary chain drive. In addition, SYN3® Lubricant is designed to provide the correct lubricity for the anti-wear requirements of transmission gears and for improved seal protection. This formula is approved by Harley-Davidson® for use in all stages of engine life and is not detrimental to the break-in stage of engines.


I use Syn 3 in the engine and Redline V Twin Transmission and V Twin Primary, I think it improved my shifting and noise from the primary and transmission