I like your un-scientific approach. I think that is a very good observation.

Steve[sm=icon_rock.gif]

 

This is my first post. A little about me: I was an automotive Driveability technician for a little over 20 years. I rode metrics for about 8 years when I was a young guy. While I'm not exactly a virgin, I'm 48-years-oldand it has been years since I've parted my legs and this is the first time I've been with a Harley.

Having said all that I can tell you from experience that rubber and other synthetic engine and/or driveline seals do "cure" to their environment. Therefore, it is true that you do not want to wait too long before introducing synthetic oil or indeed you can develop lubricant leaks - more often than not, "seepage." However, Ido not know of one instance where these leaks cannot be stopped simply by putting the regular oil back in.

Nothing is actually harmed or damaged by trying the synthetic oil; you're just out the cash for another oil and filter change. Yes, you do need to change the filter again if the synthetic does not work out for you, even if it's only been 100 miles. Just like Harley states, some oil is not compatible with other oil and can break down almost instantly when mixed.

So, will synthetic oil work for you with 13,500 miles on your engine? There is no way to know until you actually try it. If it doesn't leak or seep out through any of the seals, it's fine. If it does leak or seep, you'll have to put the other oil back in - it's really no biggy except for the expense of doing so.

Lastly, I'm glad to hear the twin cams make a lot of upper end sounds; I was a bit concerned about this on my bike. In the business we learn to differentiate between a "sound" anda "noise;" a sound is normal, while a noise is not normal So, I'm glad to know this is a Harley sound

 

The big benefit comes from better protection in high temps when riding. It protects the engine better with less thermal breakdown, well worth the additional cost.
The reason some motors leak/seep after the change( usually high milers ) to syn oil is that it cleans the motor better than the dino oils do. It doesn't damage anything.

 

There is some measure of truth to this. Fossil oil oxidizes more quickly than synthetic and the result is sludge and varnish, which can collect around gaskets and seals. This gunk can mask a weak seal, and since most synthetics have superior detergent properties they will dissolve these contaminants and expose the flaw(s). Unless the fossil oil has not been changed regularly and has compiled many miles, there should be nothing to worry about. I personally have never seen this happen, but I've seen it described in credible articles and it makes sense.

At only 13.5k miles and if you've been changing your oil regularly, you should have no worries. Don't get sucked up into propaganda from HD or boutique oil companies, or suggestions that only "motorcycle oil" will suffice. Do some research and make your decision. Any major synthetic oil of the right SAE grade, with or without "motorcycle" on the label, will work fine in your V-twin.

 

Excellent info

 

If you were using straight non-detergent mineral oil and had maybe 3X more miles on the bike, you might run into problems when the varnish deposits were washed out of the engine. With the milage you have, especially if you have been using detergent oil (don't think you can get anything else these days), you shouldn't have any problems.