What oil should I use for cruising at 12,000 rpm?

Status
Not open for further replies.
Joined
Apr 2, 2009
Messages
124
Location
College Park, MD
I have a 2001 Kawasaki Ninja EX250. These bikes have engines that wear out relatively quickly due to their high revving nature. My redline tops out at 14,500 rpm. However, I once did the math and these engines actually last as long as a good car's engine in terms of revolutions. My engine is extremely clean and currently running Shell Rotella T 5w-40 with 100mL of Lubro Moly MoS2 additive. My clutch is immune to MoS2 probably because it is a fiberglass-steel clutch and not a steel-on-steel clutch. However, I am very concerned about the wear in this engine. I would rather not have to go through the hassle of dropping the engine and replacing it with another. My question is what oil to use to maximize longevity? I would run 60 weight oil in it if that was what it took, but one thing that has to be taken into account (and I am not sure how to approach this) is that the cam chain tensioner is poorly lubed and is the actual device that explodes first when there is no more adjustment left in the automatic tensioner. Would an extremely heavy oil slow this from happening as long as possible? One more concern is that these engines are known for having a oil pumping issue: under hard braking there is oil pressure loss due to poorly designed return galleries. Would a very heavy oil slow this down a bit? I absolutely do not care about increased gas consumption or performance -- just pure longevity.

My climate is extremely humid and min/max temps are 17F to 110F.

I asked Redline and they posted this:

Thank you for contacting Red Line Oil, in your Kawasaki I would recommend the 10W40 Motorcycle Oil, if offers low volatility for reduced vaporization and consumption plus good protection for your range of operating conditions.

I remain unconvinced this is the greatest anti-wear weight though. I would like someone that knows a thing or two about bearing tolerances and clearances to signal the go-ahead that super heavy oils will not cause lubrication failure.
 
I would think that shearing would be the biggest issue with your machine.

I wouldn't worry so much about the brand. Use the specified grade and change it often.

I use 15w40 in my thumper and change it every 500 miles. UOA's have shown that the oil I use has sheared down to near the minimum acceptable at about that point. That is why I don't use a synthetic, they don't hold up any better in this case, as again shown in UOA's.
 
Cruising at 12.000 rpm's?

I think re-gearing would be an option I'd consider first.
wink.gif


Dan
 
It doesn't have enough horsepower to sustain climbing Appalacia at lower speeds with 120 pounds of cargo at 90 mph. Changing the gearing would slow it down far too much unfortunetly. If I lived in Texas I would change it.
 
Our engines are very different, but the biggest problem in mine and probaby yours is fuel dillution and abrasive insolubles (like clutch material) which can only be remedied by changing oil.

You sound hung up on the notion that using a really heavy oil will reduce wear. That's not the case with this or most engines. It's not a tradeoff between fuel economy and wear protection. It's between a thick oil for high-stress areas like your crank bearings, but still a thin enough oil to maintain enough flow to properly cool things and lubricate splash-lubed parts like your camshafts and the timing chain tensioner.

You're using the proper oil for this application, and I personally go without the additive. The chain tensioner (and I wasn't aware it similar to mine) might as well be considered a wear item. Eventually you'll need to adjust valve clearances and you can get in there to take a look then.

Enjoy the ride, stay rubber side down.
 
Trust me I have already done the valve job 5 times ;-)
Right now I have 22500 miles on the 249cc and hoping to hit the 100K mark someday. I won't get rid of this bike until it dies on me and I am trying to delay that as much as possible.

Wouldn't the thicker oil in this case increase oil pressure and help those upper cylinder parts get more lube? I am running 50/50 coolant with water wetter and I like to think that if the engine runs too hot the temp gauge will help me know if I am going overboard on the temps.
 
Things that are splash lubricated are lubed at zero pressure. Literally, the oil that slings off your timing chain lubricates much of your valvetrain. Increasing pressure (via smaller orifices or thicker oils) decreases flow to these parts, which isn't a good thing. This will also exaggerate the heavy-braking starvation issue.

If you want to keep the bike forever, my advice would be to use the 5-40 or 15-40 HDEO like rotella, and change every 1000~2000 miles which is fairly often.

I can see why you would worry about overheating using such a high crusing rpm and a high percentage of the output of the engine on a continuous duty cycle, but I've never heard that to be a big problem.
 
Thanks for the support guys. I think I answered my own question though.

From elsewhere:

The short answer is use the oil viscosity (and API classification) recommended by the motorcycle manufacturer for your ambient temperature, which for Ninja 250 owners is essentially 10w40 for "normal/cooler" weather, and maybe 20w50 for hotter climates (like Houston, Texas in the summer). Kawasaki has a lot of smart engineers designing and testing the motorcycles they build. Why would you not trust them over some doctor in Florida?

[Addendum] I trudged through a lot (but not all - too boring) of the article over lunch. The problem with someone writing an article that throws out tons of technical sounding terms is that readers who do not really understand the underlying physics and engineering cannot easily distinguish the truth from the [censored]. Some things in this lonnnnnnnng article are the truth and some things are [censored].

It is the truth that much of the wear in an engine occurs during initial startup, and once up and running and at operating temperature the wear is relatively low. But why?

If you read a reputable technical explanation on internal combustion engines, especially engines with plain bearing crankshafts such as we have in the Ninja 250, you will see that how a plain bearing works is that there is a thin film of oil, UNDER PRESSURE, in the small clearance between the crankshaft journal and the bearing race. The engine's oil pump pumps oil through the crankshaft and out little holes in each crankshaft journal to force oil into the small clearance space. The oil passes through the bearing clearance and into the oil sump to be filtered and reused.

The rotating crankshaft journal rides on this thin film of oil and does not actually come in contact with the bearing race. If the oil pressure gets too low for the force exerted by the crankshaft rotating and trying to move up and down with the piston force, then the crankshaft journal will push through the thin film of oil and come in metal-to-metal contact with the bearing race. That contact causes wear. Higher engine speeds exert higher forces, and therefore need more oil film support, and this is where the general rule of 10 psi per 1,000 rpm comes from.

The wear problem with cold startup is that when the engine is turned off and the oil pump stops pumping, the oil drains out of the small clearance between the crankshaft journal and the bearing race, and therefore the crankshaft journal is NOT supported by the pressure of the oil film, until the engine starts and the oil pump forces oil into the clearance space. Until the clearance is repressurized, the crankshaft journal rides on whatever residual oil is left behind (which is why some race engines use external oil pressurization for start up). As you might imagine, a very thin oil will drain out of this clearance more than a thicker oil, leaving less residual startup protection, but a thicker oil will not pump back into the clearance space as fast as a thinner oil, thereby increasing the time to refill and repressurize the bearing clearance space. One of the jobs of engine designers is balance these competing factors and select an appropriate oil viscosity for the engine design and the anticipated ambient start-up temperature (i.e., the "'x'w" part of the multigrade oil viscosity).

Bottom line - use the oil viscosity specified by Kawasaki.
 
Originally Posted By: djlinux64
It doesn't have enough horsepower to sustain climbing Appalacia at lower speeds with 120 pounds of cargo at 90 mph. Changing the gearing would slow it down far too much unfortunetly. If I lived in Texas I would change it.


Sounds like you need a bigger bike ... poor 250 is getting worked hard.
wink.gif
 
I've never heard of the 250's engine wearing out prematurely. They are known to go over 100,000 miles if they are well taken care of.

As far as cruising at 12,000 rpm, I don't think the engine was designed to do that and I think 9 or 10,000 rpm is about it. At 12,000 rpm you must be going around 90 mph in 6th gear. I'm not sure why you think you need to cruise at that speed or how you get away with it without the cops coming after you.

I have a 250 myself and honestly I have to say the best oil I've used so far is Belray. It's pricey being a motorcycle specific oil though.
 
Last edited:
Quote:
One more concern is that these engines are known for having a oil pumping issue: under hard braking there is oil pressure loss due to poorly designed return galleries.
I'm curious to know where you learned about this problem. I've noticed myself that my bike's oil warning light comes on under hard braking and I've always wondered what the deal is and if it was only my bike. I guess I know now that it's not just mine.
 
While it may not apply in any way, small aircraft turbine engines rum at 40K to 60K RPM. The synthetic oil they use is very thin. Approx equiv to a 5W oil. The loads are very high, as the engines produce maximum HP for extended periods of time.

For instance, we flew our Eurocopter EC-135 from Florida to NJ. Both engines were lubricated by BP-2380, a very thin synthetic.

Now, before you say "that's WAY different", these engines/transmissions have a gearbox that contains more gears. bearings and clutches than a motorcycle. That's how the 54,000 RPM gets converted to 385 RPM (rotor speed).

Much of the engine is splash lubricated and the thin oil protects without any problems.
 
For longevity's sake, have you considered a bike that's more suited to the type of riding that you're doing? The 250 has proven to be a bullet-proof powerplant since the 80's, but common sense says that running anything to 100% of it's capacity every time you use it will wear it out more quickly. An expensive boutique oil may delay the effect, but it won't prevent it.

I'd highly recommend looking into a larger bike that can deliver the performance you're needing without being maxed out to do so.
 
Originally Posted By: ViragoBry
For longevity's sake, have you considered a bike that's more suited to the type of riding that you're doing? The 250 has proven to be a bullet-proof powerplant since the 80's, but common sense says that running anything to 100% of it's capacity every time you use it will wear it out more quickly. An expensive boutique oil may delay the effect, but it won't prevent it.

I'd highly recommend looking into a larger bike that can deliver the performance you're needing without being maxed out to do so.


I agree. I can't stand the buzzing of my Suzuki Bandit 1200S, so I'm going Concours14. Pretty sure it's the way to go:

2009-Concours-14.jpg


The Kawasaki Concours 14 (or 1400GTR as its known outside the USA) is a mature, classy sports tourer. So we're pleased to see that its new colors -- black or a rich, deep red -- reflect that. Both are better than the previous silver at making the bike look expensive, which at $13,499, it really isn't. For 2009 it receives no other mechanical changes, but with a 155bhp engine and 155mph top speed, it didn't really need any.
 
is a nice bike, but I personally like the Yamaha FZR1300. Maintenance is a lot easier too. But to each his own
 
ROLF Love the Sig

"You haven't truly lived life until you've done 110mph in a Yugo"

They would almost fall apart at that speed :)
 
I really like to hear when people decide to keep their bikes indefinitely. So many guys buy new bikes every season trying to find the "perfect" ride. Keep that bike and take care of it.

Last week I met a guy who had an 86 BMW K75 with 719,000 miles! He bought it new.
 
Status
Not open for further replies.
Back
Top