With your autolube(injection) the amount of oil being pumped is determined by throttle opening and engine speed. So if you are at max revs and shut the throttle the pump is still spinning a high speed like the motor and pumping more oil because of th increased engine rpm.

Controversial point here...


The benefits of pre-mix are:

You always get a constant ratio of fuel:oil, and it can easily be altered (dyno a bike on pre-mix at different ratios to see the effects on power!)

As long as you have fuel, you have oil!

you can run erotic (oops - exotic) oils such as Castrol A747

Removing the injector means one less thing to go wrong!

Removing the complete system is quite a weight saving

All great for the track, however, disadvantages for the road (and sometimes track) are:

Erotic oils tend not to "mix" so well, so fuel doesn't store. Make it - use it!

Inconvenience - just top up the tank with the autolube system!

Run out of fuel = run out of oil!! You better be quick on that clutch lever!!

As Pierre says, shut the throttle in 6th gear at max. speed, and you lose a certain amount of lubrication

But... although this last one is true, keeping the autolube in a racing scenario is not necessarily ideal!

Consider the shutting the throttle down at 120mph/200kmh in top, therefore shutting down the majority of fuel flow to the crankcase (vacuum, power jets, etc. will still supply a certain amount under closed throttle conditions), but the autolube's still pumping oil in at high speed... wind the throttle on and you will not have optimum mixture (and consequently, lose power) until the excess oil is used! Not really much of an issue to most of us... unless you're Roberto Rolfo's up-and-coming little brother I suppose, and then the amount of time with a closed throttle will be considerably less than that of us mere mortals anyway!!! :D

Make sense?

At the end of the day, premix is down more to do with personal preference than anything else these days as, like Dave Ett' says, the modern injector systems are very reliable.

Do you want the weight and convenience, or the sweet smell and consistency? That's really all you need to ask yourself!

Andy.
NSR-WORLD.COM