Yz450 oil drain bolt

[chrispa]

Hey guys

I just a yz 450f 08, On the weekend I completed my second oil change ( had the bike for 10 hours). I noticed in the manual the instruction to remove the drain bolt underneath the engine block, I neglected to do this on the first change. On thefirst change I replaced the oil filter and removed the drain bolt on the side of the engine block.

My question is, how come the bike still took about 1 litte of oil when I changed it the first time ( I did not remove the drain bolt underneath he engine block), but when I drained the oil the second time I removed the drain bolt underneath the engine block, and the bike took the same amount Of oil?

[CaptainKnobby]

To my understanding of your ? ......is....... I guess you overfilled it the first time.

Did you catch the oil when you drained it the first time? To see how much came out. I'm sure if you caught the oil the second time you chaged it there would have been a lot more oil that came out. I use Amsoil 10-40 MCF and when I change it I take a full QT and open it and then take another QT and pour some of it into the QT I'm going to pour in the bike.

I add oil up to the line at the top of the quart (which is the mark for 1 liter) to the QT I'm going to use.

AS it states in the manual ....You will need 1 liter of oil for oil/filter change.

[grayracer513]

You could theoretically pour as many as 3 quarts or more of oil into the crankcase when you refill after an oil change and not have any immediate outward indication that you had just massively overfilled the engine. The oil doesn't stay in the crankcase during operation, but is moved to the integral oil "tank" at the front of the crankcase, where the sight glass is. There is no extra space in that tank, so the excess is just forced back to the sump through the pressure balance passageway.

Under such conditions, the engine will be splashing around in the excess, blow oil out of the breather, and usually smoke.

[chrispa]

So having only changed the oil filter the first time round, and not having drained the oil completely, should I redrain and change it now after having changed the oil fully on the second round? Or will the oil filter be ok for another 5 hours until the next oil and filter change?

[grayracer513]

That would be the simplest.