Ok, if you do have spare time and in the mood to experiment, why not go the whole hog? Buy an used 4S bore, rebore (assuming their clearances are out of spec) port+performance AF+upjet?

If the mods don't perform, you can go back to your stock cylinder+set up.

You can come down to Bengaluru(on your CBR) for re-bore job if you don't find good places in Chennai. Would be a good opportunity to meet you also

@Aargee:- It's only on the safe side asked you to experiment with another bore. I respect your every decision made here.

Hmmm...nice thoughts; but I don't have an answer

I'm just trying to recall how I used to be few years ago w.r.t Rx...

I'm a born enthusiast of automobiles from the day I can remember; for over 13 years I used to trust a mechanic at Egmore very blindly & think he does a good job. Infact he did, but the only issue is that, all the nitty gritty things wouldn't be addressed which lead to larger issues. The last I got pissed off was, he took my 100's cylinder, replaced with 135's that too a sleeved last oversize for the price of new one!!! Looking back now, he plonked a TM28 carb on a sleeved cylinder (don't know the ported stage, must be 3 I'm guessing); what a sheer stupidity is what I feel now; he could've done the same thing with a TM26 or even a stock VM probably. That was an overkill & I realize it now.

I frankly didn't know what a sleeve meant or how all could they cheat when you don't know things.

Looking at myself now, I couldn't simply believe that I'm planning to upjet; WTH!!! Upjet!!! Damn me!!! I didn't know the meaning of this a few years ago, while now, I'm actually going to do this. Shame on me that I took these many years to learn such a simplest of simple stuff; when the mechanic used to tell me few years ago about bigger carb, I used to think this is some kind of hi-fi stuff, sounded like a technique on race track; ROTFL!!!

Every 3K kms, my Rx had to be taken to his garage for service; when I asked why does the bike need so frequent servicing, he said, its part of the norms; my foot!!! Its now around 17.3K on my ODO after rebuild, except for few consumables like clutch wire, throttle cable, rubber bushes & engine oil, there're almost no service the bike requires. Engine oil changed about 3 times. Last when I changed was at 8K & now its 17K & I think I'll change it sometimes in the forth coming week; Thanks to Sriram from me & my Rx for his advice on such a wonderful engine oil that keeps my Rx happy.

A month ago, I happened to look into one of his bill that was written in a piece of paper (probably during 2006 or something); what I can recall is...
Water wash - Rs 45
Engine oil - Rs 220 (damn it, that's the current price of any mineral oil now)
General service - Rs 300 (damn it)

and fork servicing is Rs 400; I now feel WTH is there for Rs 400 to service, that too in a bike like Rx. This is only the labour, extras like oil seal, fork oil are additional.

He couldn't fix up the engine oil leak for over years & the justification given was, 2S leaks oil & is a common problem with all 2S & he showed me some other Rx in his garage. What a stupidity on me to have believed those that day!!!

I still cannot believe myself that, how dumb I used to be; what a simple piece of engineering & why did I think it of too complex & restrained myself from learning these many days.

PS - This is what happens on a lazy afternoon when you don't have much work to look into

Sriram is worried about the good/ Poor efficiency of filtration done by UNI on open air box against dusty environment leading to dust particles entering the cylinder bore scorching the cylinder walls.

Right Sriram?

Backup with what? I'm going to be playing only with carb, airfilter & jets

Araey...Sri...I'm not touching anything on bore; for that matter I'm not even opening the spark plug, forget alone the cylinder or head. Why do I need to have a spare cylinder for that

Aargee and Ram:- Not all experiments comes out clean, even the simplest of all can error out and prove costly. It's not that I'm asking you call off the project, but as Nitesh said, it is better to do all this with a back up plan.

Aargee:- Why don't you do this summer project with an another used bore? What's stopping you? Remember, a scar on the stock bore will never be the same.

Hope i was encouraging enough to carry out your Summer experiment Aargee?

^^^ Spoke my mind Ram;
Worst case if AFR goes wrong, I can switch back to stock & get it working right? Unless disasters like cylinder bolt or something is chipped or cut off

But that was Big Bore set-up right Nitesh? A simple AFM airfilter set-up along with proper jetting shouldn't do that much harm that one would suffer other than the bike running lean, stalling, poor Mileage figures, Jerking, excessive heat & stuff if not tuned properly. I'm sure members here are knowledgeable enough not to carry on riding with excessive steam finally holing the piston right?

Also is the 17.5 Pilot's & 180 Mains a spot-on figure for UNI on a bone stock 5S running a chrome pipe? Will this vary if I'm running on the fat tube cat-con due to it's restrictive nature?

Yes, two is better than one. When i experimented the big bore on my RX, i am still glad i kept the original std. bore aside which later came to my rescue when the project failed.

^ha ha...Nah!!it was just a statutory warning
Chill...and let us know th e results

See, I perfectly agree if this is going to be a rebore job; for instance, the fellow who does the rebore screws up with the piston size. On such occasion a spare cylinder will be of great help to get the vehicle up & running without wasting time.

That's why I said, in my case, I've 3 other vehicle backup, so even if Rx is admitted in garage for weeks, I've no issues; I can still work with the kaput part. Again, if the cylinders are to be ordered & to be got over few months time, YES, I certainly agree with Deepak

PS - Now you guys are literally shaking my faith!!! I'm now getting weird thoughts like, what if the carb or reed valves or engine bolt nut cuts etc Would take months to get them fixed. Don't scare me & help me to loose my confidence guys!!! That too when I contemplating to work on my CBR!!!

This Bug will never stop biting..We will continue no matter what...

Yes, Aargee saar but the spares ones are the last remains for the hard lessons learnt on the Modified bore lol...

That's basic knowledge to cover up all the parts isn't? Considering the fact we do it for passion, wouldn't we do that? But again, if that were the case, same thing could happen with the spare ones too right

Dpak - Don't worry man Worst thing that can happen is the Rx wouldn't start; that's when CBR & Activa come to rescue; that way my routine life isn't affected & I can have my own sweet time to work on them.