My 29 Squirrel runs on R grade oil. Others have alternatives and different methods of metering. Some are converted to petroil mix and some do a bit of both. You would be best trying to find out what the previous user had set up as mixing of oil types is not recommended without cleaning through. It would appear that oiling of Scotts is perhaps the most talked about subject and opinion is varied. However I believe that your starting point is what went before. You can smell the type of oil on mine and it has a Pilgrim pump set to drip at a suitable period on both sides. I also have some oil in with the petrol for safety about 50 to one. Never been in a minefield before!!!! Phil
I gave myself a true headache in trying to run the bike on straight 40 through the pilgrim pump and help things with silkolene comp 2 in the petrol. The result was that the rings ended up totally seized in the pistons and my compression was zero after 200 miles. I knew oils did not mix, vegetable and mineral, but not two stroke and four stroke. I run a good 2 stroke oil throughout now and generously too.