Dirk is our mentainance specialist. I can only repeat what I learnt from him.
Synthetic is worst of all oils for the Estrella! Synthetic is for modern short stroke motors. You should use "cheap" normal oil for the Estrella like 10W40 (hope you use the same number system in Hong Kong). I think because the oil film might break down on the long stroke of the Estrella motor when you use synthetic oil. But Dirk can surely explain this better.
Well, thanks for the flowers, Andreas, but I do nothing else but evaluate expiriences from others and me myself. There is just one main reason for using NOT synthetic or semisynthetic oil in the engine from the estrella, and this reason is the clutch.
Synthetic oil is more steadfast and more durable than mineral oil. BUT ... the synthetic oil has a lot of additives which makes the clutch slip. And that means much more scoring for the clutch. I guess it is cheaper to change mineral oil every 3000 or 4000 km than change clutch every few thousand miles.
And it doesn't have to be the most expensive oil you can get. A 10W40 is a 10W40 and it should have the same properties as another 10W40. As a rule the more expensive oils have more additives which makes the oils more durable but a lot more expensive. So I use in both of my estrellas 10W40 in winter or 20W50 in summer, and I buy the cheapest mineral oil I can get. It is cheaper to change oil every 2500 or 3000 km than using a more epensive oil which costs multiple (as also the synthetic oils do) and is good for 5000 or 6000 km.
Thank you soooo much for the information. I have changed my oils twice already, one after 800km and second after 1800km. I used synthetic as "suggested" by the official Kawa dealer here... sigh...does it make the difference that my Estrella is a 2006 model? I guess the engines and clutch are the same through the years?
So i guess I should switch to mineral oil next time... but the thing is I can imagine the dealer would say a lot things to discourage me... since they can make more money on synthetic oil instead of selling me mineral oil...
you surely have a small "owners hand book" / "owners guide" ?! What does it say? As far as I remember, there is 10W40 as one of the usable oils in it. Have a look. If your dealer says something different, show him your "owners guide".
We don't know the 2006 Estrella, but I don't think that anything with the clutch changed.
Hi there. Im using fully-synthetic oil Motul 7100 10W50 each 2500-3000km (the oil is still good condition by color when i changed), somebody told me to use expensive Motul 300V with duration abt 5-6000km. Should i change to cheaper mineral oil like Motul 3100 or Voltronic XM? Does it affects the bike's performance much?