Like anything else mechanical in the world once you know what the reoccurring problems are and implement a permanent fix for them you don't have problems anymore . Figure we had 20+ years to find cures for stupid stuff and have , a shovel done by a someone who knows the tricks will roll 6 figures if you take care of her .

 

To be honest I love Shovels both my brothers have them and my older brother has my Dad's old 67 and it still runs good. I'm guessing that bike has well over a hundred. Think they went through it in the 70's and again in the early 90's. Pretty much a family icon.

 

20W50 oil is 20 weight oil with viscosity modifiers to increase viscosity at higher temperatures. Older bikes pre evolution should run straight 50W. Newer motors work fine with 20W50.

 

Your bother may have been right 20 plus years in the past. Engines have changed. heavier oils does not really mean better any more. Stay with your 20w50

 

This is a 7 year old thread..... sure hope the OP has picked an oil by now........

 

But I WOULD take this ^^^ guy's advice.