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Great question. Thinking about it myself, but would like any feedback. Anyone?
 

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Yes I have the Takegawa cams on my 250, they are very aggressive and really help make the RPM go up fast. I couldnt tell you just how much faster as I also did the bore kit at same time. I would suggest getting them they are worth it, also suggest getting a PCV from jettuning also invest in an auto tuner. My 250 currently has a dead spot in it around 3500 - 4000 RPM, my mechanic says its the cams and we need to take it to a dyno to set the a/f mixture correctly. The dead spot doesnt affect from close to WOT, only when crusing at that RPM range, also would suggest doing a proper squish test and mill if needed.
 

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Probably be better off with a new rear chain sprocket and keep engine stock, unless you are racing.
Did that also, 13/42 stock is 14/40. I am not a full time racer, but I do attend track days as often as work will allow. If your willing to spend money on your 250 I guarentee the smiles for miles will always be there.

Here is the thread of whats been done so far, I still have a few more things I am doing to it and havent updated the thread as I have been working.

http://www.cbr250.net/forum/cbr250-performance/43817-street-track-250-upgrade.html
 

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I pulled the trigger and ordered Takagawa cams for my CBR last week. Looking at the stock dyno curves it's clear to me the top of the engines rev range is limited by the stock cam timing.

Initially I planned to do the entire "bore up" kit and get the extra displacement as well. The reason I didnt is because the bore up kit has a plated aluminum cylinder and the OEM is steel. I did not want to take the risk on a change of cylinder concept with a bike that has only 450 miles on it. Had my bike's cylinder been worn out I would have tried the bore up kit.

I was planning to install the high compression Takagawa piston but several reviews across the internet have stated these pistons have failed in a number of instances so I will remain with the stock 10.7 ratio.

I took a look at the CBR300 parts pages and see where the cams, rockers, and spring retainers are different but most of the other components remain the same. I had initially planned to use the CBR300 cams but looking at the dyno chart of that bike also shows the same high end limitation, likely from cam timing. Honda doesnt hide that this is an economy bike and fuel consumption was a key driver in the engines tuning so I am not surprised to see a similar dyno curve.

My cams were ordered from Webike in Japan and they are in route and stateside now. I already have a Yoshi sub ECU and full youshi exhaust. I'll try and get some pics for people to see as i dive into the project. Ill probably post another thread to keep from hijacking this one.

For sure I recognize buying about any other bike with a twin or 4 cylinder engine will out perform any modifications I make. This bike is a toy to me and I like to tinker with it.

My performance goal is to be able to hold 80 mph cruise speed with some in reserve for slight grades and wind. I am dropping a tooth on the countershaft and will also use a speedo healer. The intent is to get the engine higher in its rev range with the new camshafts and make use of the liberated power while cruising at higher speeds that are typical of Nebraska interstates.
 

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All posts are very useful. I went ahead and ordered the Hyper Bore Up Kit (305cc bore, sport cams, Takegawa tuner). I'll let you know when I get them on and get back to the track - although its not shipping until sometime mid-Feb (Aaargh).

My question - thoughts on whether to use the Takegawa tuner or my current PCV with a new custom dyno tune?
 

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My question - thoughts on whether to use the Takegawa tuner or my current PCV with a new custom dyno tune?
I didnt like the look of the Takegawa tuner it just doesnt look like a tuner to me, maybe I have to many PowerCommander modules. I would stick with the PCV if you already have one.
 
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So After a year I finally installed the camshafts during the Christmas break. Since the weather has been uncooperative, I have not been able to ride it until recently.
Some notes about the install- Installing the cams are not overly difficult. It’s marginally more difficult than doing the valve adjustment. The Takegawa cams use a similar timing mark as the OEM Honda cams and drop right in. I used a metal clothes hangar to keep the timing chain from falling down into the crankcase. I checked the valve clearance before removing the stock cams and the exhaust was tight. The base circle of the Takegawa cams was a hair smaller so the exhaust clearance fell into the center of the spec without changing shims. Consequently, the intake valve clearance moved to the loose end of the spec. I wish I would have readjusted the intakes at the time because there is a bit more clatter than before.
Comparing the Honda and Takegawa cams visually, you can see the extra duration and it shows in the way the engine runs.
Riding impressions- The attitude of the engine is considerably different. Before, the power was over at ~8500 RPM’s. With the cams, the engine revs right to the 11K rev limiter and pulls strong along the way. It did sacrifice a little low end grunt but in my opinion, it was well worth it. It finally runs the way I would expect a DOHC 4 valve engine to perform. I don’t think it picked up enough power to overtake a Ninja 250 but I suspect it’s much closer. The power band is soooo much more usable than the Ninja 250’s peaky response.
I installed the Yoshi DATA box and looked at the results after the first ride. As expected, at lower engine speeds, it was running a bit rich and lean at higher engine speeds using the initial Yoshi engine tune. This makes sense given the pumping efficiency of the engine is now higher in the rev range with the cams installed. Adjusting the air/fuel ratio to compensate made it marginally better from a performance standpoint but did help reduce popping from the exhaust a lot.
Having looked at the data from the Yoshi DATA self-tuning box, I am confident I would have gotten to a similar state of tune without the need for the Yoshi DATA feedback box. From what I have experienced, it appears that a slip on muffler, a set of cams, and a fuel tuner makes this bike finally worthy of the “R” suffix in the CBR250R model name.
I looked on the Honda parts website and the OEM cam part numbers are the same between the CBR250 and CBR300. I suspect the Takegawa cams can be used in the CBR300 as well. Good luck in your tinkering!
 

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Pic's or tutorial? Or were you busy with the propane business? :)
 

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^ Good post. How is the 600 holding up?
 

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^ Good post. How is the 600 holding up?
600 is running very well. (The rider can still use some improvement, though.) Had the engine built in the off season by Steve Upchurch at Race Engine Services (RES), and it's hard to keep the front wheel down exiting the turns and at the start. More power, way more smooth torque...

Taking a few podiums, but still a long way to go...
 

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Ok so had Repsol CBR250R with all the fixins Takegawa 305cc big bore, Takegawa cams, K&N air filter, Delkevic full exhaust(header back), power commander with real deal dyno tune running 100 octane leaded race gas. Everything worked like a charm but make sure you get a good connecting rod or it will spit piston out side of motor. Other then that the cams really wake up the bike good investment.
 

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Ok so had Repsol CBR250R with all the fixins Takegawa 305cc big bore, Takegawa cams, K&N air filter, Delkevic full exhaust(header back), power commander with real deal dyno tune running 100 octane leaded race gas. Everything worked like a charm but make sure you get a good connecting rod or it will spit piston out side of motor. Other then that the cams really wake up the bike good investment.
I have the Takewega 305 kit on my shelf, the cams were fitted a while back with a straight through exhaust for a 300. What figures are you getting with the power commander.
 
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