Better performance after break in?

[salishmoto]

So my NC750 has recently passed 5,000 miles and I would swear it runs much stronger than it did before. It spins up faster, more eager, and pulls harder. It's hard to compare apples to apples to a year ago, but it sure seems to be true. I wring it's neck pretty hard because it's fun to ride a slow bike fast. My other bike is a BMW K1300S and I only use the NC for commuting, taking it on longer rides every few weeks to get her good and hot and burn off moisture in the oil and let her breathe deeply. Wonder if any of you have had this experience of seemingly better performance around 5K?

 

[oldwisedude]

In my experience all machinery improves with extended use, provided it is serviced and used as designed.

My KTM 790 Duke is MUCH more powerful now at 11000 miles than it was at even 2000 miles. It just keeps getting better, as does the gearshift.

From brand new I always give the engine firm throttle openings for a few seconds, followed by a 'rest' for cool down and to avoid local hot spot distortions and potential galling. I keep repeating this 'jerky' technique for at least 50 miles. My aim is to settle the (glass-hard) piston rings to mate with the bores, before they glaze and become vulnerable to blow-by. Rings can only be pushed against the bores by combustion gas pressure from above seeping behind the ring from the top face and pushing it outwards, towards the bores. Piston ring 'spring tension' alone cannot do this.

Manufacturers make parts with breathtaking accuracy, surface finish and material quality - far better than 60's and 70's machinery. In truth you can ride a modern bike from new as if you'd stolen it and it would have no detrimental effect, probably the reverse.

When I totally rebuilt the engine in my 1973 Norton Commando 850, notorious oil-burners, I rode using the "throttle on/throttle off" technique immediately after its first start-up. I continued this for every ride up to around 100 miles, then rode it spiritedly but within its operating rev range. Being an old Brit I had to re-torque the cylinder heads and set the valve clearances twice again before it had reached 200 miles, plus extra oil changes. After that everything stabilised. The engine burnt NO oil and went like stink.

Consider what happens in modern factories as the bikes leave the production line, before being released for sale to the public, who will lovingly "run-in" keeping revs down and throttle load low. The factory actually pins the throttle wide open and runs the brand new engine flat out for a short while - and nothing breaks. Thats how good modern engines are. The wear rate is so negligible that the mechanical engine parts take a very long time to reach their optimum.

So I concur - engines will and do get faster, freer and more powerful as mileage increases.

 

[670cc]

So my NC750 has recently passed 5,000 miles and I would swear it runs much stronger than it did before. It spins up faster, more eager, and pulls harder. It's hard to compare apples to apples to a year ago, but it sure seems to be true. I wring it's neck pretty hard because it's fun to ride a slow bike fast. My other bike is a BMW K1300S and I only use the NC for commuting, taking it on longer rides every few weeks to get her good and hot and burn off moisture in the oil and let her breathe deeply. Wonder if any of you have had this experience of seemingly better performance around 5K?

I did not experience this.

How would you explain it? Honda uses a resin piston coating to reduce friction. The number of moving parts in the engine design are already minimized.. For fuel economy, in general friction was minimized in the design. Are you suggesting there is still so much friction internal to a new NC engine/transmission, that many potential horsepower are wastefully converted to heat until the break in completes?

I can’t argue that your engine seems stronger than when new; I was just looking for a possible explanation. I bought my NC new, and it’s at 67,000 miles now. Mines feels the same now, performance and fuel economy wise, as it did when new. Judging through my senses, nothing magical happened after 5000 miles.

If an NC had a dyno run done at new and at 5000 miles, the data might prove whether there is any actual engine performance gain or loss after break in.

 

[the Ferret]

My experience is similar to 670's. I notice no difference in mine between new 2 1/2 years ago, and now coming up on 40,000 miles. If anything, it is me that has adjusted.

 

[salishmoto]

I appreciate people sharing their thoughts. There is no way to be objective about this and that's fine to me. All I know is that I ride the same route every day and when I give her the gas now, getting onto the freeway and going from 20-75, she sure seems to spin up faster and more enthusiastically. I haven't done anything to impact the performance that way. It's so true how remarkable the modern manufacturing process is. If not for planned obsolescence or careless engineering (I see you Aprilia!), a modern engine can be easily made that will go hundreds of thousands of miles. I had Mercedes 300D that was known as a million mile car, because the engine would last that long. Many here run their NC's up past 75K or 100K miles and just do normal maintenance. That's an incredible testament to human ingenuity.

 

[dduelin]

Lack of subjective data allows objective data to rise to the forefront. Sometimes I think my bikes run better after washing them or performing a small maintenance task. Who knows if is true as long as my butt dynometer notices the difference.

 

[670cc]

I know my bike definitely runs smoother and even the suspension is better when the weather is great and I’m in a good mood.

 

[oldwisedude]

The Honda NC engine is designed in a clever way and significantly different to most other bike engines. The small bore long stroke format releases torque from low revs in a very useable way, removing the need to wring its neck. The total length of piston rings in contact with the bores is also much less than big bore short stroke engines. Consequently the piston ring frictional losses are very small too, enhanced by coatings as 670 points out. By cunningly using cam shafts and balance shafts to drive pumps the brilliant engineers have made an engine with less moving parts that could literally go on forever. Well done Honda.
My 2023 NC750X-DCT has only done 1100 miles, so I will not know for some time if it will free up or stay the same. All other makes I have owned have freed up considerably but the Honda is a cut above the rest.

 

[salishmoto]

The Honda NC engine is designed in a clever way and significantly different to most other bike engines. The small bore long stroke format releases torque from low revs in a very useable way, removing the need to wring its neck. The total length of piston rings in contact with the bores is also much less than big bore short stroke engines. Consequently the piston ring frictional losses are very small too, enhanced by coatings as 670 points out. By cunningly using cam shafts and balance shafts to drive pumps the brilliant engineers have made an engine with less moving parts that could literally go on forever. Well done Honda.
My 2023 NC750X-DCT has only done 1100 miles, so I will not know for some time if it will free up or stay the same. All other makes I have owned have freed up considerably but the Honda is a cut above the rest.

I agree and it's why I had wanted one since they were first introduced. When we go this 21 for my wife, I was delighted she chose this over other options like the Wee strom or similar multi-purpose bikes, just for the engine. I've said many times that I would quite seriously buy a pizza and beer for the engineers of bikes I've loved, which includes the NC. The fact it is so unlike any other bike I will ever buy, and not at all well suited to people my size without serious modifications, I still feel devoted to it as a machine of high achievement and practical perfection. I look forward to doing the valves on it eventually just to peer inside and admire the simplicity. The fact you can roam these NC forums all day and not find endless posts about engine failures or such, is a testament to the beauty of her design and execution.

 

[jknight611]

Lack of subjective data allows objective data to rise to the forefront. Sometimes I think my bikes run better after washing them or performing a small maintenance task. Who knows if is true as long as my butt dynometer notices the difference.

When, as a kid I was rather rowdy on Kawasaki Mach 4. If I knew of a pending street race i would spray the air filters with water. The bike would pull significantly harder for a few seconds till what I supposed was the cooling effect of the slightly damp air filters. 45 years later I agree bikes run better after a wash…..probably.

 

[oldwisedude]

When, as a kid I was rather rowdy on Kawasaki Mach 4. If I knew of a pending street race i would spray the air filters with water. The bike would pull significantly harder for a few seconds till what I supposed was the cooling effect of the slightly damp air filters. 45 years later I agree bikes run better after a wash…..probably.

My father dabbled with water injection in the 1950's. Moist air seems to atomise better than dry air. Engines definitely felt livelier on damp misty mornings, partly due to increased air density (and thus higher oxygen content) and partly because the water content. Whilst higher oxygen level is the more significant factor, both probably influenced carburettors more than fuel injection. Those were the days!

 

[salishmoto]

My father dabbled with water injection in the 1950's. Moist air seems to atomise better than dry air. Engines definitely felt livelier on damp misty mornings, partly due to increased air density (and thus higher oxygen content) and partly because the water content. Whilst higher oxygen level is the more significant factor, both probably influenced carburettors more than fuel injection. Those were the days!

Maybe that's why those of us who live in the rainforest conditions of the PNW find our bikes so peppy?

 

[dduelin]

I was prompted in this thread to recall that some piston driven aircraft engines use water injection to temporarily increase power (jet engines too) but the use is limited to short periods and the "water" is a mixture of gasoline and alcohol or refined kerosene (jet fuel) and a chemical mix that includes water. For more mundane applications it may be that wet rainy climates may also be cool and it is the increased density of cool air that provides slightly more power than the same amount of hot air.

 

[Dan German]

When I lived in Colorado, I loved going for a ride in the early AM. It was as dense as the air ever got. I suspect the fuel-injected bikes I ride in the modern world would not be as noticeably improved by such things.

As for the original question, I will allow that in certain cases, a bike might run better after break-in. However, the placebo effect is very strong. My cars and bikes all feel like they’re running better after an oil change.

 

[MZ5]

Higher-humidity air is LESS dense, not more dense, than dry air.

It's the vaporization of the water that cools the intake charge and thus allows more O2, more fuel, and more spark advance that is why water injection is used.

 

[Egg on Leggs]

Water also has an expansion ration of 1800-1.