Triumph Newbie Oil Question.

Hi Tommy.
477 miles in 11 years if pretty low. Unless you know different, I would expect the oil to be 11 years old and drain it all out and put some fresh 10W40 in there. I doubt it's dirty but it will be old enough to have lost some of its viscous properties.
I wouldn't waste time and money to flush it unless it's dirty. I would run it for a year or a few thousand miles and then change it if compelled to.
Why would you choose 20W oil? Is it really hot where you live?

 

I run a synthetic 20/w50 in my America as recommended by the manual. Make sure it is rated for motorcycle use. Oil for automobiles is not the same. ...J.D.

 

Mobil 20-50 V Twin here on my Thruxton 865. Actually runs smoother, less notchy shifting, and probably runs a lil cooler but I cant prove that. Been using it for years with no problems.

 

I have to deal with ambient temperature here of well over 100°f. all summer long. Oil temps. get pretty high in stop and go traffic. I have also seen it below 20°f. here in the winter. Of course I am not out riding in that kind of cold, but the multi-viscosity oil helps get oil flowing quicker on cold mornings. I use 20/w40 in my water cooled bikes. Use what the engineers recommend. That is what they went to school for. ...J.D.