when i was younger and broke i ran the cheep wal mart oil in my yamaha sx 600 at like 20$ a jug put 18 000 k on it never touched the engine so ppl can say what whatever about oil grades but if it meets the spec,most engine failures are due to oil line falling of ,freezing carbs , bad fule , poor mantiance, just going to be not as clean burning so if it has power valves you will have to clean them more,my old sx didn't so i just add and go,mix it with what ever was on sale and drive i use brp xps in my xp and my revs and head them blow up so maby i should blame the synthetic oil ,i know lots of ppl that run cheep oil and they are sledding this weekend and im rebuilding if it was a new strung out engine i would say run synthetic , but you shouldn't have a prob with your choice , just my 2 cents
seem to recall that 98 skidoos ran recommended mineral oil. run the best oil you can, some of the engine builders are recommending mineral oil over synthetic. do a search, get some info and then talk to dad.
It had 3200km when I got it, and i Put on 500km already this season. I dont think I need a rebuild till at least 5000km. Or until it breaks. And it hasnt been rat bagged in the mountains and it is mint. No dings, scratches, or anything like that. Just one ripped lug.
I ride a 69 740 big bore and that thing has never had any matinence or "refreshing" done on it since new. It was seized for 20 years and we got it running 2 winters ago. Just had to hammer the clutch til it broke loose.