Hey guyz my bike is having a weird kinda prob.... just a few days back(4 or 5 days), i rode my bike for almost 32kms to catch up with a friend, halted for about 45 mins, and then when i went to start the bike, i just didnt!!! i had to kick it for almost 5 mins and then eventually it started... and again day before yesterday in the evening i wanted to go outside, the same thing happened. but that day i didnt use it in the morning i.e it was idle till evening... now this time it took me a good 15 mins to start it, including use of the choke. and then it finally started with the choke. and the ride after that was perfectly fine just like normal... no hiccups or anything like that..

this has never happened before. i mean, it had happened long time back, and i had to get the carb cleaned as it was giving out black smoke from the exhaust....

but what about this time.. there was no black smoke or anything like that.. even the acceleration was just like how its supposed to be..

What do you guyz think?? is it a chocked carb or some electrical issues (CDI, etc etc).. the worst thing is my exams have just started and i dont want to get stranded in the middle of the road en route to my exam center(which is 28kms away from home).

Start checking it from your Fuel tap to the Carb Float. The culprit should be hiding there somewhere only.

u mean any dirt might have entered from the fuel knob into the carb?? well yes, actually i sometime feels the knob a bit too tight in turning it from off to on or reserve position...this is when the petrol level is a bit low almost near reserve.. but when i fill up to a good amount, the knob loosens up... i have experienced it a lot of times...

DO THE FOLLOWING WHEN ENGINE IS COLD.
There is a filter in the tap itself,...right under it as a bowl with nut shape...Close the tap,loosen this and see inside the bowl.You will see a lot of sediments ....clean this and the filter. Start adding 2ml of 2T per liter in petrol tank,which will protect tank from rusting, and also provide smooth tap movement.
There is a screw at the bottom of the Carburettor for bleeding the dust and muck inside the float bowl...Close the petrol tap and open this screw to let out the accumulated dust ..when it had drained out, open the tap for 3 seconds for fresh petrol to wash away any leftovers...
DO ALL THIS WHEN ENGINE IS COLD...

Accha ok... but SVC guyz should clean the tap bowl as per the schedule...i have never cleaned the bowl in these 8yrs... and is it a DIY thing?? or its the job of the mech??

And why to do it when engine is COLD?? i have experienced the problems both when engine is HOT 'N' COLD...

And what if i start the engine with the KNOB in OFF position and let the dirt and petrol in the bowl just burn away?? wont this help in removing the dirt atleast from the bowl??

@ Gixxer

Finally congratulations, after all the efforts taken for carb & finally it is here.

Will drop by to see your girl screaming for vengeance at 12k rpm

Then how do you explain,the unicorn carb?or for that matter the classic pulsar 150 dtsi's?which have bigger main jets with 26mm carb and uni i believe has even less a venturi size.

It's not that simple,unicorn has a smaller venturi carb with a 115 main jet,the achiever has the same carb with 119 main jet? and both have the biggest intake valve among bikes up to 180cc.Despite all that they are no fire breathers.The cbz extreme has a 28mm carb with a 125 main jet and it's actually slower than the unicorn!! and has the same top-end as a yamaha gladiator.

So there's more to it than just venturi size,main jets they can handle and valve size.A lot depends on the cam profile and the port geometry.That is as to where the manufacturers want the bike to develop power, along with ignition mapping and exhaust. Take tumble flow for example,which has made the HH bike have lot of mid-range but no top-end.

My eternal fav ,the RTR160 has a 105 main jet and a 26mm carb.Yet it's a bike which is tuned for shear top-end performance and it has a similar intake valve as that of the fiero which is lesser than that of unicorn/extreme/achiever.Yet it can compete with the 200cc plus bikes and match and beat 200/180 cc bikes.

I donno about her hitting 12k yet bro ,but you are welcome to check her out.
Yeah bro,buying a new carb was my last option ,so the delay.I had wanted a 32mm one to start with and it was hard to find on the used market .Then ZEN said they could source a new one for half the price,that resulted in even more wait and finally i opted out of going for a 32mm one and then i did try out a couple of used carbs with bad results.I was left with no choice really.

The p180 UG4 comes with 112.5 main and the 117.5 main is of the older version.I have the pic you took of your new carb with me and both are the same.

Good to see you going in depth into this.....It is all about Volumetric efficiency..which is dependant on many things ,including the inlet resonance.Mere valve size, or lift&timing, or larger venturi carb, or freeflow inlet, or FFe,or inlet and exhaust resonance alone will not give power or performance..it is a combination of all of these parameters that gives you the correct engine performance..For instance the ZMA with 223cc engine,on stock setting runs effieciently at lower RPM as well as higher RPM...In my ZMA the plug color never changes in city ride or highway ride.
When you increased the CC of your bike the one significant change it required was to let the engine breath,rather than choke it with a small throated Carb.
Imagine an ADULT trying to eat with adult hands, but with a chil's throat..

It is dangerous to spill Petrol on a hot engine.....if the dirt can be sucked out then it could have already happened when you were driving isn't it ?

The flow velocity matters depending on where the power is targeted to be developed. So it's not all about choke/throat/venturi sizes alone.

ya that could have happened... but are u sure that the dirt from the knob which enters the carb is causing the starting prob?? it could be some electrical issues as well...

well if at all its the dirt, y dont i experience this problem (like hiccups during accelerating and unresponsive throttle) while on the move (while riding)? and if at all its a dusty carb, the exhaust doesnt smell like their is dirt accumulated in the carb.

Other common problem is the Ignition switch developing loose contact...whenever you have starting probs., try switching the ignition switch on/off a few times...

now my question is, regarding the knob actually, today morning i filled in 6 liters of speed petrol (i always fill speed) and found the knob to operate without any tightness. now this i have experienced every time i fill in 4 ltrs or more of petrol, but its not the case if i fill half or even 1 ltr petrol just above reserve. why is it so?? if knob operates loosely, the bikes responsiveness also improves, feels free and throttle reaction is also spontaneous..and if knob is tight, its the other way round..!! why???

Secondly, as i said i use speed. so does the rusting increases because of speed, or not?? And thirdly, as u said, use 2T oil, 1ml for 1 litre of petrol. but wont it harm the engine as its a 4 stroke?? and if at all it doesnt will it be advisable to use 2T oil along with Speed petrol or Normal petrol? because speed already has addictives (so called for cleaning the carb jets and all) so adding 2T oil, wont it create a cocktail like situation?

I use speed, though my bike is old, because of the smoothness and refinement at high speeds it gives because of my daily highway runs. average wise may be a bit more(1-2km/l) than normal fuel.actually i dont care about milege. it still gives me 50 in mixed riding conditions.

And just now i started the bike, it came to life in one kick and the knob was operating freely just like after fillin her up in d morning... and i am pretty much sure that as the fuel level will reduce to about just half ltr above reserve the knob will become tight again...

i will clean the bowls of knob and carb after 11th june (exam ends on 11th!!).