Honda CBR 300 Forum banner
1 - 20 of 33 Posts

·
Registered
Joined
·
289 Posts
Discussion Starter · #1 ·
So I just dropped my bike off at the Honda dealership for an inspection, I've lost about half a quart of oil in 1k miles of hard use. Noticed about two weeks ago when I started my bike it was making that weird low oil noise engines make when they're low on oil.

So I peeped at the sight hole and with the bike leveled there was no oil visible. So I poured in half a quart of oil until it was at the proper level. Now, there's no obvious leaks on the bike so I'm trying to figure out what happened. It looks like my shift shaft seal is leaking. The seal had a minor "weep", but it doesn't look like something that would cause a large volume of oil to escape.

Does anyone know if it's normal to consume oil in these motors at that rate? When I say hard use I mean hard like freeway commutes where the engines at 9k RPM for a long period of time and canyon riding where the engine sees a lot of high rpm up shifting and downshifting.

I don't smell any oil burning while riding but I also can't look behind me to see if my exhaust smoke is blue on the freeway lol.

I have a feeling the inspection isn't going to turn anything up, and they probably aren't going to check my valves so I'm just really curious, if anyone else knows more about these motors let me know. Thanks!
 

·
Registered
Joined
·
188 Posts
I keep my revs between 7 and 9000 most of the time and mine uses about the same oil as yours.(over a distance of 3500 miles)


I am accelerating hard through the gears on twisty roads rather than constant throttle position on a straight road.


Mine shows no signs of a leak anywhere.


I never let mine drop below the middle of the sight glass.
 

·
Premium Member
Joined
·
5,460 Posts
According to google half a quart is 473 mls (I only know metric) so yes nearly half a liter does sound a bit excessive for only 1000 miles.
Firstly tho you need to sort out the leak around your shift shaft so that you can eliminate that from the equation. If there is a leak obviously your dealer will sort this under warranty.
Then you can accurately work out just how much oil your engine is using.
I ride my bike hard too and change my oil every 4000kms (2500 miles). Between changes I might put a splash in or nothing at all sometimes.
 

·
Registered
Joined
·
447 Posts
I notice a small amount of oil usage with my CB300F, and have added a little oil 2X in 3900 miles...but only about 50 ml between oil changes to keep the oil level in the middle. It still wouldn't drop below the lower line, but there is a minor amount of oil usage so I suppose that's normal. My bike runs very well. This is the 4th or 5th report of oil usage. One was a cracked block, but I'm not sure we know what the others have been. The good news is, it's really easy to check the oil a sight glass compared to a dipstick.
 

·
Registered
Joined
·
487 Posts
I find freeway speeds, over the limit use more fuel then city. As for oil level are you sure that the oil was full to start, checked from level ground? Doesn't take much an incline to significantly change the reading. But yeah the bike does consume a little oil. Oil level went down a few millimeters after 3k miles.

Think I answered the wrong thread but this kinda covers it too.

In the last 2k miles I did very hard riding mostly same as what you describe you did. But I am running a 15t so my rev is down by 500+rpms or so.

Better quality oil gets consumes (burns off) less so start using synthetics, full synthetic not that blend crap.
 

·
Registered
Joined
·
93 Posts
Are you using the Honda GN4 oil? I was running Rotella T5 10W-30 and I was losing a lot of oil. I switched by to GN4 a few hundred miles ago and there has been no noeable drop since then. I'm not sure if it's a coincidence or not.
 

·
Registered
Joined
·
289 Posts
Discussion Starter · #8 ·
Are you using the Honda GN4 oil? I was running Rotella T5 10W-30 and I was losing a lot of oil. I switched by to GN4 a few hundred miles ago and there has been no notable drop since then. I'm not sure if it's a coincidence or not.
Yeah I'm using gn4 10w-30, changed once by me after break in and then again by the dealership for the first service so the dealer set it to the proper level I would assume :serious:

Getting close to the next service interval. I might switch to synthetic.
 

·
Registered
Joined
·
151 Posts
I use the Honda GN4 oil and do the change every 5000km. I always check the oil before I do the change and it has never been below the empty line (always about half way between the lines if not higher).
 

·
Premium Member
Joined
·
5,460 Posts
Getting close to the next service interval. I might switch to synthetic.
The issue wont be related to what type of oil your using if you want to save your $$$
Without wanting to start another oil debate I personally don't believe these motors which have a relatively mild state of tune and complexity warrant the expense of synthetic oil.
 

·
Registered
Joined
·
188 Posts
I agree with Kiwi,at 6000 km I changed to Motul 100% synthetic but changed back to Honda 4t when I had my 12000 km service done last week.
Up to 6000km with mineral and 6000 to 12000km with synthetic the bike was using about the same amount.
If you wanted to keep your bike forever maybe fully synthetic might reduce the wear slightly.
I think changing the Honda oil more frequently is a better bet.
 

·
Premium Member
Joined
·
5,460 Posts
I know honda says 10w-30 but I recommend a 40, so 10w-40. Since these motors rev pretty high just cruising along.
Yeah I use a 10w-40 as well. Dunno if you guys have Castrol oils in the states but the one I use is Power1 GPS 4T. Long name but its reasonably priced and seems to do the job. According to the blurb on the container its 'part synthetic based'.
As we all know, the main thing is just to change the stuff :D
 

·
Registered
Joined
·
59 Posts
This may be a dumb question, but have you checked the tightness on all your bolts?

Do you see signs of leakage on your garage/driveway/parking space?
 

·
Registered
Joined
·
447 Posts
If you want a cheap synthetic oil with a JASO MA rating, Rotella T6 sells for about $20 a gallon at Walmart (less with recurrent rebates from Shell) which makes it cheaper than most designated motorcycle oils that are blends or dino. Actually, I found some Valvoline 20W50 motorcycle oil (dino oil) on sale for under $3.79 a quart and I'm using that for the TExas heat. I'll change to Rotella T6 for the rest of the year though next month. I am also not convinced there is any advantage to synthetic over dino oil for this bike, but peace of mind is worth something. Most of the people who are concerned about oil do way more oil changes than recommended in the manual anyway. I know I do. I have 3950 miles on my bike and have changed the oil/filter 3x already....at 165 mi./ 640 miles, and 3400 miles... and will probably change it again around 4500 miles.
 

·
Registered
Joined
·
289 Posts
Discussion Starter · #16 ·
This may be a dumb question, but have you checked the tightness on all your bolts?

Do you see signs of leakage on your garage/driveway/parking space?
Not a dumb question, I've gone over a lot of little bolts here and there but haven't touched anything around the motor. The oil drain plugs not leaking I know that's a good one haha. No oil spots or runoff found anywhere except there's some on and around the sight glass, and the seal around the shift shafts wet otherwise the motors spotless.

Bike should be back any day now they said they wouldn't keep it for more than 2-3 days so I'll update with the results when I have them.

Kind of seems like oil consumption is a normal thing? To a point I guess. Maybe it all depends on how you ride.
 

·
Registered
Joined
·
21 Posts
Not a dumb question, I've gone over a lot of little bolts here and there but haven't touched anything around the motor. The oil drain plugs not leaking I know that's a good one haha. No oil spots or runoff found anywhere except there's some on and around the sight glass, and the seal around the shift shafts wet otherwise the motors spotless.

Bike should be back any day now they said they wouldn't keep it for more than 2-3 days so I'll update with the results when I have them.

Kind of seems like oil consumption is a normal thing? To a point I guess. Maybe it all depends on how you ride.
I'm in the same boat . Interested in hearing the result.
 

·
Registered
Joined
·
447 Posts
I hope you guys get this figured out. All of us want to know what the deal is with losing oil since several people have reported it. Other than the cracked engine block, I don't think anyone has reported back what the problem was...if they ever figured it out.
 

·
Registered
Joined
·
1,498 Posts
Oil doesn't just disappear. It is either leaking out or being burnt and expelled with the exhaust gases. Either way, it should be visible.
 

·
Registered
Joined
·
93 Posts
One other thing I noticed was that (as a new rider) I was lugging the engine a bit in the 4K range. I've learned to stop doing that and keep the revs around or above 5K when accelerating. That, and switching back to GN4 oil, were the only changes that I made before I noticed the oil loss stop. I stopped lugging the engine before changing the oil (400MI before) and I didn't lose any noticeable amount compared to before where I lost 2/3 a quart over a couple thousand miles.

I have a few hundred miles on my 300 after the change and it's still sitting at the top line for oil.
 
1 - 20 of 33 Posts
Top