Honda CBX 1000-oil choice Mild ambient temps/high engine temps

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Currently in my bikes, I'm running 15w40 Rotella t4 in an OIF Triumph Bonneville (huge capacity and never gets hot), Kawasaki semi-syn racing 2T oil in a H1 Kawasaki, and for my CBX that I'm finishing I'm considering what to run in an air cooled bike that will generated much more heat than my other air cooled motors I've used. Almost exclusively I run 15w40 T4 with no ill effects on any wet clutch air cooled motor but the CBX will have much higher cylinder head temps then I have used that oil in the past. CBX's tend to consume a little oil and when idling in traffic will consume more. I will not be using this bike in traffic or ambient temps over probably 75f max (Alaska) but it will be ridden hard when used. Cylinder head temps can get in the high 300s with these and though I have an external oil cooler and low ambient temps, I want to choose an oil that handles heat the best. It's been a while since I've even had to think about anything other than t4 and Kawasaki 2 cycle oil so I'm checking in for some recommendations based on first hand experience from high temp air cooled bikes that are ridden hard.

Oil capacity is 5.8 quarts with the cooler. Pretty big sump but this oil gets worked hard. Factory fill is 10w40.





1633123067_f31a9c5b-210e-4c46-b4a9-c7a1bd7208fa_mmthumb.jpeg



Thanks
 
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It sounds like you really can't go wrong with Mobil 1, 10W-40 MX4t. Another possible choice is a diesel oil such as M1, 5W-40TDT, which despite it's lower 5W rating, has a pour point of -48F .

MX4t's pour point of -49F means it's likely to flow well enough in any conditions you are likely to start the motorcycle in.
 
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That's a real special piece of two wheeled architecture. I've used Valvoline 10W-40 syn motorcycle oil in my bikes. AK is beautiful. I went up to Denali once and toured the inner passage way. I'd live there if I could tolerate the cold. BTW, this is my latest new (antique) ride and I'm still trying to acclimate to it.

1633896364519.jpg
 
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Chevron Delo 400 15w40 works well in air cooled UJMs having a single oil for the tranny and wet clutch. Air cooled engines tend to contaminate the oil with particulates more than water cooled engines, and one thing we learned with air cooled aviation piston engines is that non-synthetic oils are better at holding that stuff in suspension until it's captured by the oil filter. More on that here.
Regarding the other question: Mary Anne. Definitely.
 

jayg

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It sounds like you really can't go wrong with Mobil 1, 10W-40 MX4t. Another possible choice is a diesel oil such as M1, 5W-40TDT, which despite it's lower 5W rating, has a pour point of -48F .

MX4t's pour point of -49F means it's likely to flow well enough in any conditions you are likely to start the motorcycle in.
I'm not worried about pour point at all. The bike won't get ridden below 40F and any 15w40 can handle that. I just need an oil that can hold up to high sustained oil temps and I think my conventional 15w40 will be toast after some hard riding approaching 400 degrees.

Chevron Delo 400 15w40 works well in air cooled UJMs having a single oil for the tranny and wet clutch. Air cooled engines tend to contaminate the oil with particulates more than water cooled engines, and one thing we learned with air cooled aviation piston engines is that non-synthetic oils are better at holding that stuff in suspension until it's captured by the oil filter. More on that here.
Regarding the other question: Mary Anne. Definitely.

Air cooled UJMs? Universal Japanese Motorcycle? There's a pretty wide gap in power and heat a kz400 and a CBX1000 can put out.



Anyway, I'm leaning toward Amsoil Metric MC 10w40 syn. Amsoil 10w40 High flashpoint and viscosity looks fine. Anybody else with first hand experience with a 10w40 synth that has held up to sustained track temperatures?
 
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Here's a pic of my 1979 CBX. I use Mobil MX4T 10W40. My bike (and possibly yours) uses a crazy spring loaded compression drive for the generator and if it doesn't get the required friction then the generator won't charge at low RPM. I would use an oil specified for motorcycles and one that carries the MA-2 rating.
CBX and ZX14R.jpg
 
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...
Air cooled UJMs? Universal Japanese Motorcycle? There's a pretty wide gap in power and heat a kz400 and a CBX1000 can put out.
...
I ran Delo in an air cooled dyno tuned modified GSX-750 that made 100 RWHP. That's plenty of power and heat. Worked fine.
That said, there's certainly nothing wrong with Mobil 1, Amsoil or the other recommendations.
 
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I'm not worried about pour point at all. The bike won't get ridden below 40F and any 15w40 can handle that. I just need an oil that can hold up to high sustained oil temps and I think my conventional 15w40 will be toast after some hard riding approaching 400 degrees. ...
PS: it would be interesting to test that notion. Run a conventional 15w40 for 1000 miles of the hardest riding you can give it then send in a 3 oz sample for UOA.
 
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1971 Kawasaki Mach III , The [ex] love of my life . Had many motorcycles after that which were better in every way, none have had the feel of that engine.
 
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Here's a pic of my 1979 CBX. I use Mobil MX4T 10W40. My bike (and possibly yours) uses a crazy spring loaded compression drive for the generator and if it doesn't get the required friction then the generator won't charge at low RPM. I would use an oil specified for motorcycles and one that carries the MA-2 rating. View attachment 74073
One on the guys at work had one way back when. Not many people ran syn oils back then. 1400 Ninja? I will humbly can say you have a great taste in motorcycles.
 

jayg

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1971 Kawasaki Mach III , The [ex] love of my life . Had many motorcycles after that which were better in every way, none have had the feel of that engine.


My H1 with FBG port work and Denco chambers would probably pull on my CBX if I kept the front tire on the ground.

Alrighty I’ll be surfing for a 10w40 syn that fits the bill. Thanks all
 
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My H1 with FBG port work and Denco chambers would probably pull on my CBX if I kept the front tire on the ground.

Alrighty I’ll be surfing for a 10w40 syn that fits the bill. Thanks all
Cafe style low bars may do the trick ! They made a 100% difference . Also,I preloaded the springs in the front forks with Suzuki axle spacers and 20W-50 oil for fork oil but that was in 1971. The Mach III is the only bike I really miss.
 
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Anyway, I'm leaning toward Amsoil Metric MC 10w40 syn. Amsoil 10w40 High flashpoint and viscosity looks fine. Anybody else with first hand experience with a 10w40 synth that has held up to sustained track temperatures?
The A product and the M product match each other quite well, and are completely interchangeable with regard to performance, shear stability, High Thermal Stability and a number of other criteria.

I suggested M, as it is a world class, top-shelf oil, and it's available in every WalMart, Autozone or other locations.

If you've come across the motorcycle oil test, you'll note that while A and M perform equally, A contains just a huge dose of Calcium for acid neutralization, where M contains Calcium, Magnesium and Boron. Boron has excellent anti wear properties. Does this matter? Probably not much, but ya never know.
 
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Engines from that era were tuned usually very lean which also means they also ran very hot. A lot of that heat can be reduced tuning it to make more power (Rich). I would immediately get a jet kit in it. I have used Dynojet kits and they always made improvement across the board as DJ does the tuning work in developement.


Kits usually include main and idle jets if needed for different altitudes and proper profile slide needles and springs to tighten part throttle response. AFAIK the kit also takes into account that the innermost cylinders have slightly different mixtue requirements then the outside ones. The 05 Yammi FZ1 i did had different jets on inside cylinders.

As an example my 2012 Kawi C14 would burn my shins when stock. Adding a PC5 and tuning it reduced temps considerably from solid 5 to 3-4 bars out of 8 on the temp gauge. And shock no more burned shins. I know its not carbed ...same result.

Thats a really nice bike there. My Dad bought a candy apple blue 71 750four and used to smoke the Harley/BSA/triumph buddies at the time. He got me into the whole thing as I helped him build it.
 

jayg

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Thanks I'm familiar with jetting changes and I'm leaving this one stock. Runs great I just haven't bought a dedicated motorcycle oil in years since I haven't had to think about it. Worst case, I'll upgrade to a larger oil cooler and test at the end of next season
 

jayg

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You could try 15W-50 or 10W-50 motorbike oil in your CBX. I don`t know if thicker motorbike oil than that even exists.
Thicker doesn't necessarily mean better with heat. Just a 40 wt that is great at handling high heat without breaking down too quickly is what I'm leaning toward.
 
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