oil question

[confuddled]

greetings gearheads have a quick question-
I have a cb750 k8, has the oil tank on the side that doesnt seem to drain! This being said, there is no dip stick in the engine, so i have filled it from the engine block at the top in the past with the required amount of oil. Now i have the task of refilling it but heres where im at-
I have all the oil drained that i could get out without removing the oil filter cap, but im not sure how much excess oil to allow for thats still in the block. In the owner manual, it takes 3.7 liters, but Im wondering just how much more to add, and how to tell when i have enough. Also wierd that the oil tank doesnt drain- will this cause problems later/is this common?
Thanks

[Re-run]

The tank does NOT drain. If the engine is off, it holds the oil. Oil only circulates through the tank when the engine is running.
You fill the tank and then start the bike and idle it for a bit and gradually the level will drop as oil circulates.
After a few minutes, the oil level will drop and in the end you will have filled about 3.5 quarts.

[Lucky 1]

It is a dry sump system.
The oil is not held in a normal oil pan.
Almost all of the oil is in the oil tank.

Fill the oil through the oil cap on the oil tank.

[shinyribs]

Confuddled,the tank does just like Re-Run and Lucky says,the oil remains in there without draining back to the engine.But when it comes time to change the oil there is a drain plug on the tank that you need to remove to get all of the old oil out of the tank itself.

Your oil fill cap should have a dip stick on it,too.   Good luck.

[rrgunslinger]

See plug on bottom of tank

[Lucky 1]

Here is the same photo with an arrow.


This will drain the oil in the tank.
There will be some oil in the filter.
There will a little oil in the oil lines and in the sump.

I would not drain the sump because you could create an air gap.
I would just drain the filter housing when you change the filter, and the oil tank.

Or just follow the instructions in the workshop manual.

[seestheday]

Interesting.  It is really different on the DOHC's.

[Re-run]

The sohc has 3 drain points. Tank, filter, and pan. I drain all 3 as the pan still holds some oil. While I have the filter housing off, I hit the starter in short bursts and I get more oil out. You have to catch it as it shoots a good foot.