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Discussion Starter #1
What sort of oil should I put inside my cbr300r?

I cant really understand the jargon inside the manual.

is Honda
GN4 20W50 Oil the correct oil?
 

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What sort of oil should I put inside my cbr300r?

I cant really understand the jargon inside the manual.

is Honda
GN4 20W50 Oil the correct oil?
Honda GN4 oil is recommended by Honda, but for the CBR300R (as well as the CBR250R) the recommended viscosity is 10W-30 (or GN4 10W-40 can be used if your Honda dealer is out of stock on the GN4 in 10W-30).

The GN4 20W-50 is intended for use in the older air cooled singles (like the XR & XL models).

You can also use other brands of 10W-30 or 10W-40 oil, as long as it is a motor oil specifically designed for motorcycles with wet clutches. You do not want to use motor oils made for cars, as they typically contain additives that can cause clutch slippage if used in a motorcycle application. Also, motorcycle specific engine oils contain additive packages designed for the transmission, whereas motor oils for cars don't.
 

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I'd say 10w40 for hotter climates, and 10w30 for milder climates
 

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Discussion Starter #4
Honda GN4 oil is recommended by Honda, but for the CBR300R (as well as the CBR250R) the recommended viscosity is 10W-30 (or GN4 10W-40 can be used if your Honda dealer is out of stock on the GN4 in 10W-30).

The GN4 20W-50 is intended for use in the older air cooled singles (like the XR & XL models).

You can also use other brands of 10W-30 or 10W-40 oil, as long as it is a motor oil specifically designed for motorcycles with wet clutches. You do not want to use motor oils made for cars, as they typically contain additives that can cause clutch slippage if used in a motorcycle application. Also, motorcycle specific engine oils contain additive packages designed for the transmission, whereas motor oils for cars don't.
massive thanks for the detailed explanation - I'm trying to increase my knowledge of the bike and how to maintain it. I feel like my safety depends on my machine operating correctly, and being completely ignorant of the mechanics is quite unwise.

just checked my local shop, they have honda GN4 10w-30 oil - I'll probably pick that up tomorrow and give the cbr a top up.

do you know the difference between HP4 and GN4?
 

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massive thanks for the detailed explanation - I'm trying to increase my knowledge of the bike and how to maintain it. I feel like my safety depends on my machine operating correctly, and being completely ignorant of the mechanics is quite unwise.

just checked my local shop, they have honda GN4 10w-30 oil - I'll probably pick that up tomorrow and give the cbr a top up.

do you know the difference between HP4 and GN4?

HP is higher performance oil apparently. Likely need to change it a little less, mind you I just change the oil at the end of the season so it's fresh for next year. I prefer a full synthetic oil on my triumph and will likely use the HP myself for the wife's cb300f


https://www.jcmotors.com/t-oil-viscosity.aspx
 

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Honda HP4 is a synthetic oil. I'd recommend not switching to a synthetic until you have at least several thousand miles on the bike. Mineral oils (aka petroleum based oil) like GN4 are generally better suited to new engine break in than a synthetic oil, the reason being that synthetics don't allow the engine & transmission internal moving parts to wear together as well as what a mineral oil will. This is evidenced by the very fine metallic particles you see suspended in the drained oil at the 600 mile oil change, which is normal and indicates that the internal moving parts are wearing in together. Honda fills the engines at the factory with same GN4 you buy from Honda dealers as their so called "break in" oil for this reason. I myself used the GN4 mineral oil at the 600 mile service/oil change, and then switched to a full synthetic oil (Valvoline 4T Synthetic 10W-40 Motorcycle Oil) at the 4000 mile oil change. IMO, the biggest benefit to using a full synthetic oil is that the gearbox seems to be a little smoother shifting. But that perceived "improved smoother shifting" could also be due to just getting more miles on the bike... my CBR250R now has about 15,000 miles on the odometer. I think the whole mineral vs. synthetic debate really comes down to personal preference. There is that old but true saying: The best oil is clean oil. With that in mind, and regardless whether one uses mineral or synthetic in these bikes, I would not go more than 5000 miles between oil & filter changes.

I should mention another thing you'll need to be aware of when you're checking the engine oil level: That the bike is on a level surface and is held upright off of the side stand, so as to get an accurate reading in the sight glass. If the oil level is in between the two marks next to the glass, the oil level is correct. Too many new owners look at the sight glass with the bike resting on the side stand, and not seeing any oil in the glass think that the engine is low on oil. Then they end up overfilling the crankcase, which is not a good thing.
 

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Honda HP4 is a synthetic oil. I'd recommend not switching to a synthetic until you have at least several thousand miles on the bike. Mineral oils (aka petroleum based oil) like GN4 are generally better suited to new engine break in than a synthetic oil, the reason being that synthetics don't allow the engine & transmission internal moving parts to wear together as well as what a mineral oil will. This is evidenced by the very fine metallic particles you see suspended in the drained oil at the 600 mile oil change, which is normal and indicates that the internal moving parts are wearing in together. Honda fills the engines at the factory with same GN4 you buy from Honda dealers as their so called "break in" oil for this reason. I myself used the GN4 mineral oil at the 600 mile service/oil change, and then switched to a full synthetic oil (Valvoline 4T Synthetic 10W-40 Motorcycle Oil) at the 4000 mile oil change. IMO, the biggest benefit to using a full synthetic oil is that the gearbox seems to be a little smoother shifting. But that perceived "improved smoother shifting" could also be due to just getting more miles on the bike... my CBR250R now has about 15,000 miles on the odometer. I think the whole mineral vs. synthetic debate really comes down to personal preference. There is that old but true saying: The best oil is clean oil. With that in mind, and regardless whether one uses mineral or synthetic in these bikes, I would not go more than 5000 miles between oil & filter changes.

I should mention another thing you'll need to be aware of when you're checking the engine oil level: That the bike is on a level surface and is held upright off of the side stand, so as to get an accurate reading in the sight glass. If the oil level is in between the two marks next to the glass, the oil level is correct. Too many new owners look at the sight glass with the bike resting on the side stand, and not seeing any oil in the glass think that the engine is low on oil. Then they end up overfilling the crankcase, which is not a good thing.



Good call on waiting for the full synthetic, never thought about the break in benefits of the other oil. Great post.
 

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Oh dear. I'm not sure I want to wade in here, because engine oils for bikes is a very complex area and I don't want to scare newbies.

However....... :)

The big difference between car and bike engines, which makes this area so apparently tricky, is actually in the transmission, not the engine. Whereas cars have separate lubrication systems for engine and transmission, bike engines and trannies often share their oil. Additionally, car clutches sit in fresh air (albeit hidden inside a 'bell housing') but many bikes use 'wet clutches' which sit in the very same oil as the engine. MotoMike referred to this earlier.

Obviously, oil is designed to REDUCE friction, whereas clutches rely on friction to transmit power from the engine to the gearbox. The role of the clutch is to permit this power transfer to be interrupted while gears are changed and when stationary. Consequently, it is important to use the right grade of oil in order to maintain clutch friction within design parameters.

Why is this tricky? Well some oils provide more friction reduction than others and this can affect clutch operation. Whether this change in clutch behaviour is noticeable enough to be a problem I can't say, never having experienced the issue myself. It is easy to imagine though, that high quality synthetic oil, being a 'low friction' lubricant, could have this affect. Some car engine oils also contain additives which can actually harm wet clutch friction material.

For myself, I stick pretty rigidly to manufacturer's recommendations because (1) I don't have the knowledge required to second-guess Honda in light of the above and (2) because I change my oil frequently, thus negating many of the long-life advantages of expensive oils, I would be wasting money. There is also the matter of warranty to consider, where applicable. It might be that using an oil outside of the manufacturer's recommendations could invalidate a claim if engine lubrication was implicated in an engine failure.

I also take the view that, with low-tune, unsophisticated engines such as the CBR's, fancy oils are not necessary.

If you can confirm that a 'better' oil does no harm to the clutch and you don't mind spending the extra money, then go for it. It's a simple way to 'modify' your bike and maybe release another half horsepower! :)

Oh and another thing (just to complicate matters further), those of you living in extreme climates (very hot or very cold) will have to choose oil with flow characteristics (viscosity) to accommodate those conditions. All oils have 'safe operating temperature ranges' and oils that flow well at very low temps may overheat and fail at very high temps (though some expensive oils have wider operating ranges). I haven't got the manual with me but all car manuals cover this, providing alternative oil grades for such conditions. If the CBR manual does not, your local Honda dealer should be able to advise.
 
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I'm in the camp of using an average quality semi-synthetic oil and change regularly with filter done every time. I use 10-40 cos its most common and reasonably priced. I change it every 3K miles.

I once put fully synthetic in an XR200 and made the clutch slip instantly. Even tho I drained it off the clutch plates were still impregnated with the stuff and in the end I had to fit heavier clutch springs to get it sorted. Expensive mistake I'm wary of repeating.
 

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I'm currently running Shell Rotella T5 10W-30. On my next change I think I'll go back to the Honda oil. I was unable to find an oil that is JASO MA certified like Honda recommends. I don't know enough about oil/lubrication to really decide if that's important though.
 

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got the HP4 10w-30 from the shops today, gonna give the bike a top up!
Has the first service been done? If it hasn't, I wouldn't use HP4 to add to the mineral oil that is in the engine now. Save the HP4 synthetic until the second oil change at 6000 or 7000 km, when the engine will be fully broken in.

If the first service hasn't been done yet I'd just go ahead and change the oil & oil filter now instead of adding oil. Also a lot of guys don't wait for the 600 mile (1000 km) first service to change out the oil & oil filter, and do at 200 miles (350 km's) or less. Again, I'd recommend using the GN4 mineral oil for your first oil change, not synthetic.
 

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At the first oil change I go to Rotella T6. It's full synthetic and inexpensive. It's sold as a diesel oil but meets the JASO MA standard and many people run it in their motorcycles. $23 a gallon at Walmart, less when Shell offers a $5 rebate.
 

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At the first oil change I go to Rotella T6. It's full synthetic and inexpensive. It's sold as a diesel oil but meets the JASO MA standard and many people run it in their motorcycles. $23 a gallon at Walmart, less when Shell offers a $5 rebate.
I think the 5W-40 is, but not the 10W-30. I have a quart in the garage, I'll double check later.
 

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I say don't buy synthetic blend oils at all, they are the biggest rip off of the oil industry. Consumers assume that a synthetic blend is a 50/50 ratio, it is not. Far from it but does cost half way between full synthetic and dino. In actuality they could put in one drop of synthetic and call it a blend, and that is what they pretty much do. There is no where the oil companies say what the ratio is, it is guarded because they only put in a small ratio of synthetic.

Also Honda brand , or any motorcycle brand oil is also a rip off. They put their logo on it and double the price. It is no better then any comparable oil company brand.

As for engine break in, use what ever you want it doesn't matter, never has and is only a perpetuated myth based on ignorance.

So use oil weight for your conditions and make sure that it is not energy conserving to prevent clutch slip.

As for me I use synthetic cause it last longer. Lets me change the oil once a year after the rainy season. I like Rotella T6 cause it is high quality and cheap at walmart for a gallon.
 

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honda gn4 oil kit comes with 2l 10w30 dino oil
which has different characteristics to synthetic
and which influence initial break in via
contacting surfaces which require some
inital wear as part of break in..

the kit comes with correct filter and gasket..

lubricating effects of dino vs synthetic oil
on new mating surfaces re wearing in
is not rocket science and easily verified..

after break in [repeating MM good advice]
there are many options from continuing with
dino or various good semi-synthetics such as
silkolene super4 10w30 and full synthetics..

depending on how you ride, the main factor is
how long you leave it in there before changing..
if you change within recommended mileage
or less then dino oil is fine..

'abuse' by the way, includes only riding short
distances/times, which wont give oil time
to heat up to full operating temp thus
expel moisture in the oil [causes sludge etc]..

for me honda gn4 is the easiest as its all in one box
and i get a discount as a 'valued customer'..
the 2l is plenty for topping up if needed..

while this is as mentioned a fairly low stress
single engine with liquid cooling etc,
it still has relatively small oil capacity
[1.5 - 1.8l depending on filter change]
so its prudent to change regularly
esp if typically ridden short distances..

imo its worthwhile changing oil/filter
[as MM] well before the 600 service..
[i have always changed oil as soon as
arriving home with new road hondas]

and magnetic drain plugs are also
a good idea.. cant hurt anyway..
 
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