Hi,Wayne! I think 1:5 is way too heavy.Maybe 1:16 would be better.But if I owned a nearly new bike like that,I'd go with Mobil 1 fully synthetic and forget the duralube.Just call Mobil and ask `tech-service' to be sure.I use synthetic in anything I really care about because of its superior heat resistance and resistance to thinning out.I've got it in my Merc Grand Marquis,my Eddie Bauer AEROSTAR van,and my 32 quart capacity shuttle-clutch tranny in my humongous backhoe.It has never showed discoloration,signs of burning,etc.Any moped of mine that has a requirement for automatic tranny fluid will get the best from me! BYE!