Thanks Superglide. I didn't know what the owner's manuals for the new bikes said. My '94 says 5K oil changes too...
I guess the dealers make more money on the shorter OCIs, and that may be part of the reason they recommend the 2500 mile drains.
But I think that judging from the condition of many oils we review at 2000 to 2500 miles in these engines, it would be best to change the oil at 2500, or maybe 3000 miles max.
Harley probably doesn't want their engines to last more than about 50,000 miles before needing a rebuild (in which case most folks would just trade the bike in) so the 5000 mile drain probably suits that life cycle.
There are two Evolution engined bikes in the Milwaukee museum which have been documented to have gone over 400,000 miles without a rebuild. One of the guys--Dave Willet--lives about 75 miles from me, in High Point, NC. HD gave him a new bike in exchange for his '87 Tour Glide with about 420K on the clock. He used regular HD 20W50 dino oil at 2500 mile OCIs to achieve this mileage figure. The other guy, from the Pacific Northwest (can't remember his name), also used the Harley dino 20W50 on 2500 mile OCIs, and that bike ran more than 460,000 miles. He, too, received a new bike from Harley Davidson in exchange for that one. There was an article in American Iron about these two bikes about three or four years ago. Dave Willet had over 200,000 miles on his Twin Cam bike (the one Harley gave him for the Tour Glide) at the time the article was written. He was still using HD 360, and changing at 2500 miles--not surprisingly.
So I think the 2500 mile dino oil drains have set the bar...
Dan