Re: Honda CBR 250R

The exhaust I'm using is custom and free for me, I will make the final exhaust after a few months,basically aim is to increase power but at the same time not affect my economy. Mods I mean is big mods, i am blessed to have the resources for stuff like bore-work, increasing piston size by making a custom one, basically increasing the cubic capacity too, coupled with ecu tuning. Note this is all just plans, if I can do this it will be in the future and I would have a 2nd or 3rd bike by then, it would be converted into a track bike, but its just contemplation, I'm planning to do small changes at a time cause the CBR is such a fantastic bike, it got a lot of space for major engine mods, obviously requires expertise which I have in the form of my uncle who does up and owns a lot of bikes like tz,tzr250/350, rd350 track spec, lc125, aprilla 350 chassis with a tz engine and a bunch of more chassis. I jus put on this test exhaust to see how it fares in the conditions, like daily use, long use and all that .

Re: Honda CBR 250R

If you have the resources, why mod a 250? You can upgrade to a bigger bike without reliability concerns..

Re: Honda CBR 250R

As Sanjay said, u can refer the previous posts for high level details regarding performance modifications. And yes doing big mods will affect torque and power w.r.t rpm.

If i remember correctly CBR makes peak power around 8k rpm, so you can make modifications such a way that you can shift peak power from 8k to around 6k or at 10k rpm. Again this involves some serious modifications.

Before you go in for engine modification you can try to reduce the weight of the bike which will improve the overall performance of the bike. You can checkout the thread Making of Kawasaki Ninja 300 San http://www.xbhp.com/talkies/general-...a-300-san.html to find more useful information about weight reduction. :thumbup:

Ram

Sent from my C1904 using xBhp Connect mobile app

Re: Honda CBR 250R

Much thanks for the link, also I have a doubt, I have ridden about 17000km but mostly inner and putter city, haven't put a proper out n out ride or tour, I like to know if this may affect my engine or performance in any ways? I'm planning this year , start off on 200km-400km rides and then move up to the bigger numbers. Cause I heard some rumor I need to atleast ride once a long ride before 20000km, not sure if its true or not.

Re: Honda CBR 250R

True that but this is something I like to do, don't exactly have the resources to buy a bigger bike... I'm starting on small mods then move up to wherever I can, even if I switch bikes, I'll keep my ceeber and convert it into a track bike.

Re: Honda CBR 250R

Hi,

I usually don't like to interfere with the CBR 250R's ownership thread.. however seeing your enthusiasm...would request you to do keep in mind "There is no replacement for displacement!". Big bore kit and all the stuff will give you a maximum gain of say 3 - 4 bhp @ the cost of engine reliability and longevity. You are looking at cost per bhp of roughly 15 - 20k. 286/300 cc kits that are known in the race circuits are from Takegawa with not very good results. internet research will yield you with plenty hits of blown up engines not just once but multitude no. of times.. Also it is a false belief that a vehicle made for racetrack can be used on everyday road... both conditions are completely different. Street requires stop and go and also a mixture of riding scenario. On a race track you are trying to go as fast and as hard as possible. Unlike with a CV carburettor motorcycles the moment you upgrade to a big bore kit, the OEM stock PGM-FI ECU parameters will simply not work. You will either have to source an after market ECU or a piggy back one to change various parameters like fuelling, Ignition timing and rate of fuel flow, fuel pressure, bigger injector etc. To get proper fuelling.. you will have to run your bike on a dyno. Going for this route also means your vehicle simply becomes an open loop system. So the moment the there is any change in ambient temperature/elevation the fuel maps will also have to be changed. Imagine doing that minimum 4-5 times a year, every year till you own the modded CBR!

Have already burned my fingers in the past (FZ18 thread)... in the pursuit of more power with a stock bike only to realise the golden statement mentioned above in bold: stands true in every manner. If you want more power, reliable power then moving up the CC ladder is the way to go. You may add suspension, mass centralisation and braking upgrades at a later stage as your budget permits in order to quench your track day needs. All the senior riders are well too aware of the consequences of engine upgrades which claim "better than stock and more reliable.. offering you more power and more mileage than OEM engine!". So long as your priorities are set and you know what you want, the direction you want to take then good luck with your endeavours.


Cheers,

Re: Honda CBR 250R

Can't deny what u said,what do u think I can do max? like to increase my performance to a extent that it won't blow my engine or as u said keep it on dyno runs? OK for the moment I only have 2 mods in mind, exhaust and maybe ecu tuning, but I'll only do the ecu tuning after some research obviously, anything like touching the engine and opening it up requires a huge amount of expertise, I am blessed to have an uncle who owns about 10 bikes, plus another 10-12 chassis. He primarily owns a tz 250, lc125, rd350 track spec, rd350 normal, a couple of aprilla 350 frames, and many more. Well he's gonna put a tz engine on the aprilla frame and use for the track. He did all the Suzuki gixxer sf bikes for the Suzuki cup, soo making parts is not a issue, but I will heed your advice, I'll be honest , I hate the stock exhaust, I wanted something more gruntier and something which makes the bike feel free to ride. I'm planning on a custom made exhaust system, after that I'm only taking into consideration of ecu re mapping, but obviously I'll do all the necessary research, beyond that I plan to rent out my bike that is the conversion of a track bike, but not overly extravagant changes, jus drop in weight and some power increase. But for now exhaust system is in the pipeline and any other do's or dont's ya recommend for slight modding, for city riding and touring?

Re: Honda CBR 250R

Try removing the air filter cover which is under your seat. Low end seems to improve for a couple of owners. Also you get an intake drone at 4k rpm

Re: Honda CBR 250R

Jus the cover or entire air filter? Cause I have seen in a fair many threads, that OEM air filter will let less dust into ur engine compared to performance air filters, lot more dirt and particles enter ur engine compared to tried and tested stock filter?

Re: Honda CBR 250R

Just the cover. Or else, just remove the snorkel (air hose) attached to the filter and let the cover be in place. Causes absolutely no damage, gives an intake drone between 3-6k RPM and minutely betters the low end.

Re: Honda CBR 250R

My two cents on getting the most of your bike, get track training and modify the bike accordingly.

Oil Query

Hi All,I have a 2 year old CBR250 has run about 20k kms. I usually use Shell Advance Ultra 10w40 Fully Synthetic oil in every oil change i.e usually between 7-8000 kms intervals. My riding is usually in the city and once in a while I take it out on the highway. Bike runs around 1000kms in a month. Few of my friends with the same bike go for a Mineral Oil with the same grade and change it every 2000 kms. They also say that it makes the bike run smoother and give good performance. They are also of the opinion that Synthetic Oil just slightly lasts longer.Since I want the best for my bike what exactly is recommended?1.) Stick to Shell Advance Ultra 10w40 and change it at the above mentioned intervals? 2.) Go for the Mineral or Semi Synthetic Oil of the same grade and change in short intervals?Please help me out as I am confused and really want to extract the best of this awesome machine.Thanks in Advance,Samuel

Re: Oil Query

I find shell advance ultra best suited for cbr. 7-8k interval is a bit on the higher side. I change it every 4500-5000kms. I have Used shell semi synth once and was not at all satisfied with the engine roughness.

Re: Oil Query

Mineral oil- basically used for run in of the bike.not recommended after 5000kms or else it won't be much time until you see galzed pistons etc.
Semi synthetic-80% mineral and 20% synthetic.decent for basic city use and not meant for ripping(occasionally though)
Doesn't protect the engine that well.
Fs- fully synthetic.that's the engine oil you should look once your bike completes almost 7000 kms.gives your engine full protection from wear and tear and you can rip your bike with this engine oil.it's smooth and meant for bikes above 200cc.
You can ask your friend not to use mineral as its not helping much .

Re: Oil Query

This is a myth. Piston glazing is independent of oil used. When people baby the bike a lot in run in phase, rings/piston walls get glazed before bedding in. If you change rings in an already glazed bore, rings won't bed in.
Mineral oils provide decent protection (up to 40-50%) of FS oil intervals and cost 25%. I feel mineral oils are fine for city usage unless one doesn't hit the highway regularly.