100cc engine oil overfill

naveed

Member
My RC 390 only shows correct engine oil after a ride, so I ended up with 1.8l of engine oil and now it's showing higher level after a ride. I was wondering if there is a way to drain extra engine oil without opening the drain bolts and how bad is to have 100ml extra oil on RC 390?
 

Formula390

Supporting Vendor
Vendor
Country flag
Common problem for folks who haven't read the riders manual for oil level. It's not a big deal to pull oil drain bolt, and just keep it right at the threads... drain a small amount out, and put the bolt back in. Obviously you gotta do this with the engine at ambient temp, but it's easy enough. Then, take it for a ride and check your oil level and if you took too much out, add some of the oil you drained back in.
 

naveed

Member
I read the service manual and put 1.7l with ratio rite, but the oil level on my RC 390 was very low when I checked with the procedure mentioned in the service manual.

To clarify how to check the correct engine oil level, should I go with the oil level after a ride? If I follow the exact procedure mentioned in the service manual, the oil in the sight glass is always low.
 

CDN Duke

Member
Country flag
How are you holding the bike level? Not on kickstand I hope?

Needs to be at operating temperature and level front to back and side to side.
 

Falkon45

Member
Country flag
You don't even have to ride it. The bike just has to come up to Temp. Turn it on, let it idle and come up to normal temp, turn it off, stand it straight up and check the level. Catch it before the ride if it's low. Not after.
 

naveed

Member
I see, thanks a lot! I drained the oil from suck location as mentioned by @mattv. It shows correct level now with bike upright without any stand.
 

ReidMcT

Active Member
Premium Member
Elite Member
Site Supporter
Country flag
I just did my 600-mile oil change and had a similar experience. I followed the manual, except that I got extra oil to drain by moving the bike up off the side stand. After measuring and filling 1.7 liters, I ran the engine for about 2 or 3 minutes (having also warmed it prior to the drain procedure). Then I turned off the engine, held the bike upright, and saw nothing in the sight glass.

Note: I do not know how long I should wait between engine shut down and observing the sight glass. Any input on that? Thee manual does not seem to address that.

Anyway, I added more oil in 50cc increments, running the engine for at least a minute before checking the level again. I put in a total of 1.95 liters in order to get the level just above the minimum.

I look forward to feedback on this. Meanwhile, I will run the bike up to temperature and have another look at the level today. With such a relatively small volume, I can appreciate that a few CCs can make a big difference and that correct level is important.
 
Top