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20W-50
DaxRushMLA - 26/5/18 at 01:34 AM

Guys, What do yous think?

I own a Dax with a Cbr 1100xx. I have an oil cooler and have just increased my sump size from 4L to 5.4L. (had to re-baffle the sump)
The manual states I should put semi-syn oil 10W - 40 however due to the below reasons I was thinking of changing to
15W - 50 or 20W - 50 fully synthetic. What are your thoughts?

Pro's to changes
1. My Dax engine bay retains way more heat then of a bike engine so oil temp increases quicker!
2. I live in Malta and its quite hot & humid during the summer period here.
3. Fully synethic is thicker and therefore will reduce less movement in the sump (I blew a bearing on my last unbaffled engine)

Cons
1 - I will have an accusump & it might reduce the time of flow to get to the oil gallery if there is a lack of oil pressure. - this is just my thought!
2- Might reduce circulation in the sump due to oil thickness & my new sump partitions.

What are your thoughts pls?
Stick to 10W-40 as per manual but change to fully sync
15W - 50
20W - 50

Brendon


Bigboystoys - 26/5/18 at 06:32 AM

Fully synthetic on bike engines is a no go as normally causes clutch slip. I would just stick with a good quality semi synthetic 10-40 As recommended by pretty much all the bike manufacturers


ReMan - 26/5/18 at 08:26 AM

+1
Don’t use fully synth
Do use recommended grade


r1_pete - 26/5/18 at 08:59 AM

Fully synthetic BIKE oil will be fine, do not use car oil it has friction modifiers which ruin the clutch.


motorcycle_mayhem - 26/5/18 at 09:23 AM

Fully Synthetic only, anything JASO MA2. Film strength in high temperature operation will give you a margin of safety, just don't obsess over the oil pressure readings, they can get insanely low.

Circuit racing/testing in somewhere warmer than on this grey damp rock, I'd shoot for a 15/50. I use a 10/40 here.

A Motul or Silkolene product will fit the bill.