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Discussion Starter · #1 ·
Well I know about speed and power. But what thoughts do you guys have on porting and polishing the head of the cbr250? I have the exaust, a k&n air filter, and plan on getting a power comander, but do you think its work the money for a port and polish and what kind of performace do you think that would yeild?
 

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Discussion Starter · #3 ·
Well I have a hook up at a machine shop that performs these up grades or else I wouldnt bother. Besides its my money so if I want to drop a few bucks here and there I will. And ferther more im gonna look in to a bigger bike but this will be my goto bike.
 

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Discussion Starter · #4 ·
Sorry guys not trying to be an ass but im tired of others careing how we spend our money. When guys like myself and im sure others post a question we want a response on that subject not a judgment. but please keep your contructive advise coming.
 

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When guys like myself and im sure others post a question we want a response on that subject not a judgment. but please keep your contructive advise coming.
This is why I always use the search bar before asking a question here, A LOT on here think it is there business to tell you how to spend your money on YOUR bike, I am sure he meant no harm in his reply and was stating the obvious.... however he had no idea that you have a friend that owns a machine shop and would do the work for little $$ or none at all.

IMO I would give it a try, take it and have it dynoed before and after post up the results.
 

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Sorry, no useful advise to offer. It would be interesting to see what, if any, gains in power could be found inside this engine. If Honda keeps this bike in their line for number of years, maybe the aftermarket will come up with a big bore kit... 300 cc? Maybe a camshaft set? Would those engine mods require an increase in throttle body size, to get enough fuel/air mixture to feed the little beast? As I said, all I have are questions, no answers.

About thirty horsepower would be pretty nice for this motorcycle. For those of us who plan on keeping their CBR's for a long time, putting some money into it to realize some significant performance gains isn't unreasonable at all.

I say go for it. :)
 

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As posted in another thread on this forum somewhere... some people like to tinker with what they have and see what they can do with it. To the OP and everyone else, please remember that alot can be lost in the translation of text and it can be easily misunderstood. In the future think about multiple possibilities of intent on others posts as I doubt alot of people are here for the specific reason of insulting others and when most choose to insult it's rather blatant. As well there is little reason to post for no other reason than to fan the flames, let it die down and don't aggravate the situation.

With safe regards from the mostly frozen north.
 

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Wow. Y'all have become so serious, self righteous, and boring. I have decided to ban myself.....moderator please delete me.
 

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Wow. Y'all have become so serious, self righteous, and boring. I have decided to ban myself.....moderator please delete me.
Probably the best forum news I've read all day.
 
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Well I know about speed and power. But what thoughts do you guys have on porting and polishing the head of the cbr250? I have the exaust, a k&n air filter, and plan on getting a power comander, but do you think its work the money for a port and polish and what kind of performace do you think that would yeild?
Porting will yield approximately zero horsepower improvement. You're more likely to mess up the torque characteristics and idle than add more than .2 hp.

As for polishing, it will yield exactly zero horsepower.
 

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Porting will yield approximately zero horsepower improvement. You're more likely to mess up the torque characteristics and idle than add more than .2 hp.

As for polishing, it will yield exactly zero horsepower.
I think the above is true. Modern manufacturing allows accurate geometry and the design is usually well optimised. What could give some extra power is a higher compression ratio. This is a design for the entire world and if you can get better fuel than the norm a higher CR will give some benefit. If you shave the head you need to know how to check piston/valve clearances and how to avoid miss timing the camshaft.

Speaking of which a different camshaft would definitely be able to deliver more top end power, probably at the expense of this bikes low and mid range torque. It can't be too long before someone markets one.

regards Roadster
 

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I didn't mean my post to come across as insulting, and I apologise if it did. It's just for the amount of money and effort you'll put into making this bike only a tiny little bit quicker, you'll be able to buy a seriously quick bike, that has the brakes and chassis to cope with the extra power. It's your money, and you are free to spend it as you wish, but in my opinion it would be better spent on a fast bike, if that's what you want. I can't understand the point of buying a slow bike that works perfectly well for the reason it was built, and then waste lots of money trying to make it nowhere near as quick as a real fast bike, which will hold it's value much better, and is built to go fast. ;)

PS: I don't know how insurance companies work in your part of the world, but there are implications with modifying your bike over here. Where I live, you must tell your insurance company of any mods you do to your bike, or it may render your insurance invalid.
 

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Discussion Starter · #18 ·
Hey man thats cool iv just seen so many post with one guy putting down another I just had to say something. And in maryland you can mod out your bike just about any way you like. Btw no ill will man.
 

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Hey man thats cool iv just seen so many post with one guy putting down another I just had to say something. And in maryland you can mod out your bike just about any way you like. Btw no ill will man.
No worries Mate. I can come across as a bit brusque sometimes, I'm just trying to give you my opinion. No offence was intended. ;)
 

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Speaking of which a different camshaft would definitely be able to deliver more top end power, probably at the expense of this bikes low and mid range torque. It can't be too long before someone markets one.
That's about right.

The only possibility for real power gains will come from aftermarket camshafts and increasing compression by shaving the head and/or swapping the piston.

Until then, there's no point in doing anything else except for looks and sound.
 
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