Which oil?

[Fazer Jake]

I currently use Semi Synthetic CASTROL POWER 1 10W40.
 
My question is, would the engine perform better with a thicker oil? When my fazers engines cold the gearbox is sublime feels very smooth.
 
Soon as the oil warms up the clunkiness sets in.

[kebab19]

Not sure how that's happening.....the purpose of a multi-grade oil is to change viscosity dependent on how warm the engine's operating temperatures are. The gearbox clanging / clunking is normal, particularly shifting into 2nd. My Fazer1000 makes the same sounds, probably a Yamaha gearbox design quirk.

The optimum oil for our climate's temperature range is 10/40w  - covering from -10 to +40 centigrade

http://www.vulcanforums.com/forums/showthread.php?t=7342&page=2      for a handy chart

 

[limax2]

I'm not the oil expert on this forum (or any other forum!) but for what it's worth here is my basic opinion.
Any oil gets thinner (i.e. viscosity reduces) as it get hot, even a multigrade. It also gets thinner with use. So when the oil is cold the gearbox may well feel smoother. However a thicker oil will not be good for the engine with the small oilways and small clearances on plain bearings. Hence why it is bad for the engine to be rev-ed too much before it gets warmed up.
I would stick with the recommended grade.

[dogruff]

Agree with Kebab,It tends to be a Yamaha trait (gearbox clunk.especially 1st in my experience)Previous bike EXUP,one before TDM860 - both had massive clunks when engaging 1st.The FZR was the worst.When starting from cold i had to hold the front brake to stop it lurching forward,and this was with a near full service history and a new clutch with EBC springs.Just a trait with no long term damage,you kinda'get used to it after a while.
 When it comes to oil grades 10w/40 is the recommended grade for the UK climate by all manufacturers.I use any good quality oil.Just bought 20l in the asda sale(£10 x 4l).I think it was Castrol Magnatec Semi-synth 10w/40.Lucky i got paid  at the same time the sale was on.

[Fazer Jake]

Agree with Kebab,It tends to be a Yamaha trait (gearbox clunk.especially 1st in my experience)Previous bike EXUP,one before TDM860 - both had massive clunks when engaging 1st.The FZR was the worst.When starting from cold i had to hold the front brake to stop it lurching forward,and this was with a near full service history and a new clutch with EBC springs.Just a trait with no long term damage,you kinda'get used to it after a while.
 When it comes to oil grades 10w/40 is the recommended grade for the UK climate by all manufacturers.I use any good quality oil.Just bought 20l in the asda sale(£10 x 4l).I think it was Castrol Magnatec Semi-synth 10w/40.Lucky i got paid  at the same time the sale was on.

Doesnt car oil degrade wet sump clutches? Thought it was a strict no no

[Dead Eye]

From everything ive heard, stay away from car oils. Something to do with the additives in the oil that will destroy the clutch (well, make it useless) though im sure someone will have a much better explanation

I did an oil and filter change about two weeks ago and I ended up getting some Castrol Power1 10W40 (same as yours Fazer Jake) - I didnt exactly shop around and wasnt terribly bothered by the price (something around £30 I think). But having said that my bike has felt better since I did my mini-maintenance and probably does the opposite - its very clunky in 1st and 2nd but once warmed up its a lot smoother, especially through the higher gears.

[subby]

Im a fan of Castrol Power 1 semi myself.. use it in both bikes and never had a problem. A little more expensive maybe but i prefer knowing i have decent stuff in the engine and it likes it too!.

[Farjo]

Regarding car oils, there's an interesting discussion here: http://foc-u.co.uk/index.php/topic,666.msg3946.html#msg3946

[dogruff]

Well! That's the talk on the street Jake.I haven't used "motorcycle oil" for a long time now.My last courier bike was a CX500.Sold it to another dispatcher with 156k as an emergency 2nd bike.All  my babies have always ran on Castrol GTX.Maybe the key is regular oil/filter changes.Have always done mine every 4 months without fail,with only one siezed bike(CX500 @230k).,but everyone will have their own opinion.Mine is that quality oil is just that.Quality oil!.

[Gnasher]

My question is, would the engine perform better with a thicker oil? When my fazers engines cold the gearbox is sublime feels very smooth.

No
 
I would recommend Silkolene Comp4 10w-40 for a Fazer it's semi synthetic and suits the bike really well.  In my experience notchy gearboxes are down to worn or out of adjustment clutches mainly the latter.  Adjust or replace as required, when you start the bike pull the clutch in once it's off choke and while it's warming pump the clutch a good few times before engaging first you will find the klonck is greatly reduced.     
 
Bike and car oils are different mainly due to the fact most modern bike engines and gearbox share the same oil with the added complication they also have wet clutches, the higher concentration of additives in car oils can make the clutch slip.   

[Major Rant]

 

Regarding car oils, there's an interesting discussion here: http://foc-u.co.uk/index.php/topic,666.msg3946.html#msg3946

   I stand by everything I wrote in that thread ... because it is all still true      To summarise: Car oil and bike oil are the same - unless your name is Rossi. Mr Yamaha says use any 10-30 or 10-40 oil that meets the SL or CF spec ... so do what he says. His warning against "car oils" results from the occasional use of friction modifiers that will screw-up your clutch - so avoid GTX magnatec cos its got Molybdenum sulphide in it. (Its a detergent-like molecule with a "metal end" and an "oily end" so it sticks to oil and metal.) The only additive you need is Zink dialkyl phosphate - and its in oils that meet the SL or CF spec- so use them. Cheap oil (that meets the SL of CF spec) is better at 3000 miles than any 'wonder oil' at 6000 miles - so if you love your engine then use Asda semi-synth 10/30 and change it at 3K miles. The viscosity indicators (10W/40 etc) are a lot more complex than "10 Centigrade" and "40 Centigrade" - do your own research. 20/50 oil is OK in a Fazer if you live in a hot desert where the temperature never drops below 10C - if you live in the UK - use 10/30 or 10/40.   I could go on - but I won't.      

[His Dudeness]

i havent read into it but i'd be of the opinion that bike oil goes in bikes and car oil goes in cars. mainly down to the fact that bike engines run at much higher rpm so i'd imagine that bike oil is made to suit those running conditions and car oil isn't coz cars will never run at 15000 rpm.

[richfzs]

I haven't read into it, but....

Ah, the genius of the internet commentator 

If Mr Yamaha says SL or CF spec, and the oil says SL or CF spec on the bottle - then its up to the job, regardless of marketing gimmickry that sooo many people seem to fall for.

[His Dudeness]

I haven't read into it, but....

Ah, the genius of the internet commentator 

If Mr Yamaha says SL or CF spec, and the oil says SL or CF spec on the bottle - then its up to the job, regardless of marketing gimmickry that sooo many people seem to fall for.

i'd say the more typical internet commentator response would be to quote a some technical jargon that you've read off wikipidea and dont properly understand and use it to justify an argument. if you want to save a few pound by skimping on oil then go ahead.

[dickturpin]

Why do you feel it's 'skimping' if it meets the manufacturer's spec?

[richfzs]

I've never looked at Wikipedia (not on this topic anyway!)

[Dead Eye]

...A little more expensive maybe but i prefer knowing i have decent stuff in the engine and it likes it too!.

I agree, I can justify spending the extra money just for a bit of piece of mind. I'd quite happily recommend a friend to use whatever is specified by the manufacturer but its just personal preference at the end of the day