This is confusing to me. If the bike has sat for any length of time, why wouldn’t the dipstick show the actual level? If it’s a dry sump, then wouldn’t all the oil be in the tank? When the motor is running, it sucks oil out of the tank, circulates it through the engine and then back into the tank, right? So if I turn the motor off after a ride and THEN check my oil, how would that be any different than letting the bike sit for several hours (or days) and then checking it? Does hot oil take up more volume?
You're getting close, but it's really only when the scavenge Pumps are running that all the oil not actively circulating is in the tank/reservoir - as soon as you turn the engine off, the scavenge pumps stop running, and the oil starts leaking back into the scavenge/pick-up areas deep inside the engine block... but there's no non-return valve on the bottom of the reservoir nor is there a single sump for it to run into, so your oil can just 'disappear' into the block until you start up again - and that means that if you filled it to the full mark in the reservoir
after it'd been sitting for a few days, there's a very good chance that it now might be dangerously and possibly even very expensively OVER-full as soon as the scavenge pumps start pumping it back into circulation & trying to force too much into too small a container! :shocked:
And
YES, hot oil
DOES take up more volume than 'cold' oil (or oil at its ICE operating temperature anyway

) and
THAT, teamed with the fact that the reservoir/tank is only showing an accurate indication of how much oil is in the system
for a few minutes after you turn the engine off, means that if your oil is not at
OIL operating temperature when you do the level check, then you might get a substantially lower level reading than you'd get once the scavenge pumps start up again and your oil does reach operating temperature - and remember, that's the
OIL's operating temperature too, which has little to do with the coolant operating temperature!! So if you add oil to your reservoir cos the level looks low when the oil is cold and the engine's been sitting for more than a few minutes, you might be over-filling it.... how much over-full is anyone's guess, as is exactly how much excess oil it will take to hydraulic the engine & blow the crank or a rod or two right out of the bottom of the block!! :shocked: Don't believe this can happen if you will, but
I've personally seen a few of engine's that exactly this has happened to, so I'm not gonna risk it! :lecturef_smilie:
All of which adds up to the need to make sure you don't ever add more oil than specified during an oil change; and that you really should
ALWAYS use the approved Oil level check procedure that calls for the engine to have been run for some time in order to bring the oil up to
IT's operating temperature by running (preferably at highway speeds/revs) for 10-30 mins before shutting it down to do the check; and then you still need to check the oil level in the reservoir within a few minutes of that shut-down, cos if you don't do that, you stand a pretty good chance of over-filling the engine with oil and that can mean dirty things happen, if not nasty & expensive things happening to your engine!! :yikes:
Yeah, I know all this could have been done differently by BRP/Rotax, but for whatever reason, it hasn't been, so you really have little choice but to work with what you've got, cos none of this is easy (or cheap!) to change...

But it's really not all that hard to make it your practice to hold back 250ml or so of oil from the recommended fill amount when you do every oil change, then knowing that you've got enough in there to be safe, run the engine/ride the bike for the necessary time before checking it using the approved procedure and topping up
ONLY as necessary to put your oil level somewhere between the Low/Add mark and the Full mark,
but NEVER OVER the Full mark on the dipstick! And then once you know you've got it somewhere in the middle of that ADD-FULL range, simply make a practice of checking your oil level
AFTER you've gone on a reasonably good ride - cos if you check it when you stop like that, then unless there's a puddle of oil underneath the bike the next time you go to ride the bike, be it a day, a few weeks, or even some months later, the odds are well in your favour that there'll be enough oil in there for you to start & run the engine safely!

hyea:
Make sense?? :dontknow: