Full or semi

[Keny73tj]

What kind of oil do you guys use in your FZRs? I'll be changing my oil while my fairings are off. I thought I read somewhere that semi should be used but I'm not 100%. One more thing what would the standard gearing be for my 3tj1?
Thanks

[Evilchicken0]

10/40 semi sythetic the actual brand isn't so important, I change the filter every other time.

Standard gearing is fine for road use.

[kirbster]

As long as it is rated for use with a wet clutch it doesn't matter if its semi or full or even full mineral.
I am running Rotella T6 Synthetic 5w40. Its diesel rated and guys over here swear by it.

[Evilchicken0]

Engines are designed from the outset to run a certain grade of oil and the tollerances are set out accordingly. Motorbike engines have smaller gears and teeth which can pull the oil molecules apart faster than a car engine and the FZR engine is known to be a faster higher revving engine than most.

Putting the wrong oil in an engine probably won't kill overnight but in time you can place more strain on it by increasing the internal drag or by oil film breaking down and allowing the metal parts to touch.

I wouldn't expect a deisel engine to rev up to a 10,000 redline let alone another 50% on top, it's up to you what you use of course but remember your engine isn't design to use this, and that oil isn't designed to run in your engine. You, and the guys probably know more about engines than Yamaha and more about oil than Rotella

[Kurlon]

Diesel oils are popular because of what they have to withstand compared to gas guzzlers. A diesel doesn't rev like a bike, no, but the compression ratio's seen are MUCH higher, the duty cycles much longer. Net result they tend to see just as much if not more sheer action at the molecular oil chain level than bikes. An oil that can survive 10k miles in an industrial diesel should maintain viscosity / chain length in a bike for 3k without breaking a sweat. (And many have proven this with oil sample testing over here.)

For reference, Shell Rotella T6 is what my engine builder has recommended after I finish breaking in my machine if I don't want to do oil changes after every race weekend. Considering how cheap Castrol GTX can be had for, I'm likely just going to baby the bike with a constant fresh oil supply anyways. :D

[Hogdigerdy Dog]

there's several threads debating this issue, the general consensus seems to be to use semi, fully-synth has been known to cause clutch slip as these machines weren't designed for it, semi seems to be the happy medium as long as it's bike specific 10w40

i change the oil and filter for it's annual pre-mot birthday (somewhere between 4 & 5K a year) a bit over the top but oil and filters are cheep compared to a re-build

[kirbster]

I was reluctant to try it myself. But it is a 40w oil and it is JASO rated for wet clutches.
I can point you at a few threads where guys with CBR900s with 90,000 miles have used nothing but and they have included plenty of pictures from the inside of their engines. Clean and pristine.
It is about the same price here as decent dino oil. I will not hesitate to change it often as it is relatively cheap. Whereas if I had a crankcase with $80 worth of oil in it I may be reluctant to drain it if I feel the need to.

If it meets the required specifications i wouldn't hesitate to use it.

[Evilchicken0]

Like I said its up to you, but if I have to give a recommenation it will be what's recommended in the manual.

[rockTJ]

I use Silkolene 15w50 full synthetic in my 400. Out of all of my bikes, including my '10 GSX650, the FZR400 runs the smoothest. I have no problems with clutch slip at all, running an EBC FZR600 kit minus 1 plate and new genuine clutch springs. Don't have an odometer on the bike at present so I will just replace it before the next MOT is due. Because this is a 'third' bike it never does the short commute.

Chris