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This is what I was going to point out -- the new D.I. Honda Fit w/CVT runs at very low rpms compared to the M/T model! Hmm, but the CBR250R isn't direct inject, only port injected.
I just can't say I've heard of a direct connection between low RPM running, or even consistent lugging, and excessive carbon build-up and/or burned valves.

My father-in-law's Suburban (small block Chevy V8) runs about 1700 RPMs on the highway, and it's nearing 200,000 without any excess carbon or burned valve issues.

This story just doesn't add-up for me.
 

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Also - high octane (Premium) won't burn any cleaner than Regular - and it will cost you power and economy. Some companies claim to have more detergents in their Premium, but if you feel there could be carbon issues just run a fuel system cleaner annually.
Pull down an engine that has been run on premium compared to one that's been run on e10 or regular 91ron, there is a big difference.
But hey what would I know, I only do it every day...
 

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Pull down an engine that has been run on premium compared to one that's been run on e10 or regular 91ron, there is a big difference.
But hey what would I know, I only do it every day...
Why would that be? Premium (high octane) is only needed for detonation resistance - that's it. There's absolutely no benefit from running a higher octane fuel that absolutely necessary to prevent detonation. Excess octane slows flame travel - reducing power and economy. Running Premium when the engine does not require it can also make it harder to start.

There may be better detergents in "Premium" but adding a strong fuel system cleaner (Techron) once per year will accomplish the same cleaning - or better.

Unless you are comparing the same engine with the same miles run in the same conditions the findings are just anecdotal evidence.
 

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Next you'll be telling me it's impossible to stop a cbr250r from 35kph in 1.5m.
I pull engines apart all day for a living, yes you can loose hp with premium but it's bugger all, it runs cleaner. You put in whatever you like for all I care, it won't change the fact premium runs cleaner.
 

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Next you'll be telling me it's impossible to stop a cbr250r from 35kph in 1.5m.
I pull engines apart all day for a living, yes you can loose hp with premium but it's bugger all, it runs cleaner. You put in whatever you like for all I care, it won't change the fact premium runs cleaner.
Really? Then explain why.

I told you the only reason it may be cleaner, and it has nothing to do with octane.

Pulling engines apart doesn't give you all the information you need to determine if internal deposits are due to fuel type or conditions.

Believe what you want, but "Premium" isn't the best answer to keeping deposits from building-up inside an engine.

Next you'll be telling me about braking distances...because you do it all the time...
 

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Hey hey now, Lets not go into the brakes subject. I can stop on a dime..

As for Premium vs Regular... Just fill up at Chevron and call it a day and who cares what you put in?

Meh, I usually rarely ever run Premo, but when I do it's because I'm riding in the high mountains and its all uphill on the way there. Premo does *seem* like it makes a difference, but doubt it does. All I know is I ride the road often to go to Tahoe and passing power did *seem* different. But I don't fall into that thing of always getting it as I don't really care either way.

For some reason I do believe Chevron burns cleaner, and no I don't fill up at Chevron every time, I just fill up wherever I see gas. But my riding group swears by Chevron for some reason, and they always meet at Chevron's, and all gas stops are usually Chevron. They say its cleaner gas, but w/e. I could care less either way, but there does seem to be a big following to Chevron gas.

Would Chevron gas prevented the burnt valves? Highly doubt it.

And I would guess they didn't get burnt by lugging the motor.. Lugging is bad, but if anything they didn't do the VCI and you paid to get it done and they were out of spec and had to come up with an excuse.
 

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Hey hey now, Lets not go into the brakes subject. I can stop on a dime..

As for Premium vs Regular... Just fill up at Chevron and call it a day and who cares what you put in?

Meh, I usually rarely ever run Premo, but when I do it's because I'm riding in the high mountains and its all uphill on the way there. Premo does *seem* like it makes a difference, but doubt it does. All I know is I ride the road often to go to Tahoe and passing power did *seem* different. But I don't fall into that thing of always getting it as I don't really care either way.

For some reason I do believe Chevron burns cleaner, and no I don't fill up at Chevron every time, I just fill up wherever I see gas. But my riding group swears by Chevron for some reason, and they always meet at Chevron's, and all gas stops are usually Chevron. They say its cleaner gas, but w/e. I could care less either way, but there does seem to be a big following to Chevron gas.

Would Chevron gas prevented the burnt valves? Highly doubt it.

And I would guess they didn't get burnt by lugging the motor.. Lugging is bad, but if anything they didn't do the VCI and you paid to get it done and they were out of spec and had to come up with an excuse.
Premium (higher octane) will give you better performance only if you are detonating on lower octane gas. There may be conditions that will cause that, but generally the recommended octane is adequate - and the best choice.

As far as Chevron goes, they are the company that produce Techron Concentrate fuel system cleaner (my favorite, and the best cleaner IMO) so it's very possible that their fuel contains Techron to some extent. It may say on the pump somewhere. All fuel has detergents, but some may contain larger amounts or higher quality.

Those additives/detergents in the gas are what's keeping deposits to a minimum - not the higher octane of Premium.
 

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I have done some work for oil refineries. The magic snake oil is added in the tank farms and blended in before it is loaded into the tankers. The octane is determined by the cracking process in the refinery. The cleaning agents, boosters, etc. are blended in at the tank farm. Premium gas gets a better and more concentrated blend than does the low octane fuels. You get what you pay for.
 

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I have done some work for oil refineries. The magic snake oil is added in the tank farms and blended in before it is loaded into the tankers. The octane is determined by the cracking process in the refinery. The cleaning agents, boosters, etc. are blended in at the tank farm. Premium gas gets a better and more concentrated blend than does the low octane fuels. You get what you pay for.
They have you convinced to pay quite a bit for something that you don't really need then - at least not in a CBR250R.

I have seen some brands advertise that their Premium has more cleaners, but why wouldn't they all make a big deal out of it then?

If all you are after are more concentrated and higher quality cleaners you still are better running a good fuel system cleaner than running Premium. Do you want to pay up to 20 cents more per gallon for the additional cleaners - and get worse performance and economy while you are doing it?

Just run Techron Concentrate once a year - and forget buying "Premium" because it's "better for your engine".
 

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If you fill up with a Top Tier gas (BP, Chevron, Shell, QT, ect) then the same amount of detergents are present in regular or premium fuel. The only difference is the RON or knock deterrent properties. Our bikes are designed to run on 87. I only put in 87. My engine is clean as a whistle. I run fuel cleaner (B12 chemtool) through about once per season when the fuel blends change.

This is of course in the U.S. Joeboo is in Australia, so fuel may be blended differently there. But the Top Tier stations should be equal throughout their products, worldwide. At least, based on their website's information. Cheaper gas stations or non-top tier may have better detergents in their premium fuels.
 

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Really? Then explain why.

I told you the only reason it may be cleaner, and it has nothing to do with octane.

Pulling engines apart doesn't give you all the information you need to determine if internal deposits are due to fuel type or conditions.

Believe what you want, but "Premium" isn't the best answer to keeping deposits from building-up inside an engine.

Next you'll be telling me about braking distances...because you do it all the time...
I didn't say it had anything to do with the octane did I ? Premium has cleaners in it.
When you are pulling engines apart for a living you can tell a lot py the condition, I rebuild my own engines on my dirt bikes, one get premium one doesn't , both get ridden the same. Like I said you do whatever you want I don't care.
Oh as for braking distance I've already proved my point on video.
 

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Shifting back to the original question of the opening post of this thread, I'm not buying the "rider lugging the engine" theory as the reason/cause for the burned valves on the OP's bike, any more than I'm buying the idea that it's due to an inherent design flaw on Honda's part (as another poster suggested).

Regular vs. Premium grade gasoline?... I don't think so.

The statement by the OP in a later post that "the valve clearances were in spec" when the engine was disassembled, despite having burned valves at that point, doesn't make any sense. How could burnt exhaust valves possibly be measured and determined to be within specification? The answer is simple... they can't.

So here's my theory...
I'm wondering if the valve clearances were actually ever checked early on (at least within the first couple thousand miles from new) as part of the regular maintenance on the OP's bike? I'm guessing they were not checked within the first 2000 miles. Fast forward to the failure at 12,000 miles: the exhaust valve clearances have been closing up since the bike was new, and finally becoming too tight, the exhaust valves end up burnt.
 

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Discussion Starter #53
I never found values in the manual except when to up shift. 3500 should be okay. My husband was going as low as 1500. I like to run it between 4000 and 7500 but have taken it to redline several times while having fun getting on the freeway. The mechanic told husband to make it sound like he is racing it around town. That seemed to work because he said the replaced plug looked perfect and after 2000 miles would show if he was still lugging it.
 

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Discussion Starter #56
Was the Valve Clearances Inspection performed at the initial 600 mile service, or at least within the first couple thousand miles from when the bike was new?
I did take it for all services including the 400 mile one and they said it was done but I'm not sure that they actually did it. My current mechanic says that it is so rare for a honda to need them adjusted that early and he said they were still in spec so he knows that was not a factor.
 

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Yes! I was told to only use non ethanol fuel. Ethanol destroys parts quickly. Although my mechanic says to only use high octane fuel in most motorcycles, he told me that because the owners manual says to only use regular to not use high octane with my bike. Manufacturer knows best.
 

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Discussion Starter #58
Shifting back to the original question of the opening post of this thread, I'm not buying the "rider lugging the engine" theory as the reason/cause for the burned valves on the OP's bike, any more than I'm buying the idea that it's due to an inherent design flaw on Honda's part (as another poster suggested).

Regular vs. Premium grade gasoline?... I don't think so.

The statement by the OP in a later post that "the valve clearances were in spec" when the engine was disassembled, despite having burned valves at that point, doesn't make any sense. How could burnt exhaust valves possibly be measured and determined to be within specification? Of course the answer is simple... they can't.

So here's my theory...
I'm wondering if the valve clearances were actually ever checked early on (at least within the first couple thousand miles from new) as part of the regular maintenance on the OP's bike? I'm guessing they were not checked within the first 2000 miles. Fast forward to the failure at 12,000 miles: the exhaust valve clearances have been closing up since the bike was new, and finally becoming too tight, the exhaust valves end up burnt.
Lugging caused carbon buildup which didn't allow the valves to close properly causing the burnt valves. This was verified by a second party who inspected the tear down.
 

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Lugging caused carbon buildup which didn't allow the valves to close properly causing the burnt valves. This was verified by a second party who inspected the tear down.
That still seems odd...

...but running a strong fuel system cleaner once a year should be cheap insurance against excessive carbon build-up.

It just seems like there would need to be more factors involved to create the problem than just low RPM running.
 

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Yes! I was told to only use non ethanol fuel. Ethanol destroys parts quickly. Although my mechanic says to only use high octane fuel in most motorcycles, he told me that because the owners manual says to only use regular to not use high octane with my bike. Manufacturer knows best.
It's not my intent to call you out on this, but you may want to read the Owner's Manual again... the CBR250R (as well as nearly every other street legal motorcycle manufactured in recent years), is built with fuel system parts & components made to tolerate gasoline blends with up to 10% ethanol by volume (max)... it's covered on page 108 of the U.S. Owners' Manual, under the section Oxygenated Fuels.

Using non-ethanol unleaded gasoline is fine, but it can be hard to find in many parts of the country. It's certainly not widely available at all gas station... here where I live there are only 2 stations (out of about 25) that have non-ethanol 91 PON premium unleaded gasoline. FWIW, I use 91 PON non-ethanol premium gasoline in my '01 Honda XR400R, as that is the recommended minimum octane as per Honda for that engine, which has a higher compression ratio.

Also, the O/M doesn't say that you can't use premium grade fuels in the CBR250R, rather it states that the recommended fuel octane number is 86 PON or higher (U.S. spec's)... page 28 of the U.S. O/M.
 
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