Hey Guys my 2012 blade has just had its 1000km oil service and since having that done the bike feels like it has a delay in throttle. Its hard to explain, but basically if u sit at a constant speed and then twist throttle it like bogs down and then power comes back in, this happens in like a split second but you can feel it when riding, is this due to after market exhaust perhaps and losing the exhaust valve? Anyone lese had this or know what it is or could be? Cheers David
I recently read about somebody else having a similar issue with a 12 model after fitting an aftermarket can. He refitted the standard can & it was cured. I'm not sure on all the details; it may have had a full system; but I read it on this site.
Full system on my 2012 and not experienced this problem. Only thing I have noticed is a very slight over run at 4K where the ECU is expecting the exhaust valve to close.
Its strange though as it never did this untill after my 1000km service, how can that cause this all it was is oil service and filter. When you say you get slight run on u mean when u pull in clutch the revs hang while changing gears?
Nope, when rolling off throttle when the engine revs down to 4k there will be a very slight surge enough so that without looking I can tell I'm at 4K but it's far from an issue and easily rode around. If I classed it as an issue I would fit a PC. I can't explain how an oil change would affect this, what air filter have you got fitted.
Hey Yeh thats exactly what mine is doing, that surge at around 4000rpm, its very slight but u can feel it for a split second. Ok so thats due to the aftermarket can not having the exhaust valve like the std pipe? What does the exhaust valve actually do in the std pipe? I have a BMC filter installed
The exhaust flapper valve is purely there to lower the noise levels for the EU regulations. It sends the gasses through the smaller hole until 4k when it flaps open... Or if you've done the flapper mod like I have on my blade it's open all the time!
That I can't answer! I would guess its been set up in the ECU to change the fuelling to allow for the flapper. I don't know about you, but I find the engine braking seems to reduce too as it drops below 4k, and I can't work out why, unless the valve timing / overlap alters at that point; creating less back pressure.
Could the surge described by Mr.B be related to the Idle Air Control Valve maybe? "Idle Air Control Valve (IACV) minimizes torque reaction and smooths response to small throttle changes through gradual reductions of air and fuel intake when the throttle is opened and closed." 2012 Honda CBR1000RR Features and Benefits - Honda.com Also, forgot to mention that my 08 used to have the surge too, but I don't notice it any more, so presume it was resolved when I changed fuel maps.
Would that be affected by removing the std exhaust and fitted slip on? So one would need to get a power commander then to remap?
I have a standard filter and have been advised if I fit an aftermarket one then I should look to fit a PC but the standard filter in combination with the Akra race system is fine for the standard fueling and so far so good.
I have noticed this but io had a HRC 1/4 turn throttle on my 2006 and just thought it was because of that , Im fitting PCV quickshifter and a quick action throttle over winter so should sort it
Not saying this statement is incorrect but would be interested to hear where you heard this as I understood the opposite to be true. Aftermarket air filters make virtually zero difference but fitting a race system and therefore removing the cat and 2 off internal exhaust valves requires a fuel map change. Perhaps someone with more experience could clarify ?
I got the information from Akrapovic and their distributor Performance Parts. I did have to wait several months for the system to be available for the 2012 so not sure if Akrapovic have developed the system further. With 3500 miles done with no problems I'm happy with the advice. A performance filter will not make much difference to the power output but will add more air with their free flowing nature and in conjunction with a de-cat free flowing system would be enough to upset the bikes fueling and would make the requirement for a PC more important to smooth things out.
I'd of thought that removing cat and fitting race pipe the ecu would make minor adjustments to suit I still have the oxy sensor with scorpion carbon exhaust if it was running wrong wouldn't it throw up a light ? I still will be having mine mapped after PC and though
No it would just melt valves gradually so you wouldn't notice until too late is what I was told. Modern air filters and airboxes are well designed today and improve bhp by tiny amounts if any because they flow virtually no more than stock due to the originals being so good in modern bikes. K&n told me this when they used my vehicle to design one of their aftermarket kits and found no improvement. I can't argue with a manufacturer but wouldn't believe an importer personally. What seems very strange to me is the air filter makes virtually zero difference and they say it needs a remap. Removing a cat and 2 exhaust valves and replacing with larger diameter headers will flow huge more amounts of gas. As the restriction on the exhaust side of combustion is massively reduced the ability to rev easier and process more fuel is increased. As no more fuel is added without a re map the only other element of combustion is air. There is no control on air flow intake (just a hole at the front of the bike at the end of the day) so if this increases due to the removal of a down stream restriction and fuel input is constant the change results in a lean mixture. Personal I would be paranoid and want my afr checking on a dyno as riding the bike you won't be able to tell if running weak but the gradual damage could ruin your bike. Just my opinion, hopefully helpful certainly not meant argumentative.
Funnily enough (well not for him) a mates R1 eat it's valves after his PC malfunctioned causing the bike to run too lean. I ran a GSXR for 17000 miles with a de-cat system without fault so I'll take my chances but yes what your saying is possible.
