i put BEL-RAY thumper oil in and its semi-synthetic.
i was told not to use a full synthetic oil by two different people with husaberg racing and rebuilding of the motors.
everyones got there own theory and half the dealers that you ask havnt got a clue and are full of ****.
i couldnt bring myself to use DELO 400 , but i did buy some and my truck is getting better milage,,
Motorex to expensive,,,Had bad experience with MOTUL with my 2-smoker,
love PUTOLINE but from what i have read on here im not even gonna try it,
good luck