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**imjoshee** · 07-17-2012, 09:27 PM

Originally posted by rapperswil View Post

All,
I plan to buy a used Karizma R. Model year 2007 DEC. 32000 KMs. The asking price is Rs 46,000 Bangalore. Original owner (actually, friend selling on behalf of a friend, I wonder why people lie in such matters).

My purpose of buying a Karizma is for pickup, comfort and refinement.

I need some advice.

a. At this mileage what are the things that should have been changed? These are the things I can think of.
Tyres
Chain + Sprocket
Fork oil
Battery
Cables

b. Does the karizma R come with a crash guard? I do not remember seeing bikes have this.
Nope, You need to get an aftermarket crash guard.

c. How expensive are the parts? I tried reading some pages in the ownership thread, and what I gather is that the prices have come down. But my impression is that the Karizma's prices are high even relative to the quality.
They are expensive.

d. What should I look for specifically? Does the Karizma have any infamous niggles / problems. The rattling front fairing comes to mind.
Check for valve clutter & timing chain tensioner clutter.

e. Does the Karizma's headlight have an AC or DC setup?
Runs on DC. You can plonk in a 55/60w bulb using a relay without any issues.

f. Pickup wrt to the FZ16, which I plan to sell (2011 model).
No comments

g. Comfort with respect to GS150R Suzuki?
Comfort at par since I own both.

h. How good is the braking?
Enough to make the bike stop, if used wisely.

i. Do most members service their bikes from HH service centres or from local mechanics. Any names / numbers from Bangalore?
DIY

I would be thankful if atleast some of you respond, as I am not able to summarise several pages of this ownership thread.

Thanks in advance

Answers in BOLD. Also check for the life of the clutch plates. You can check this by riding the bike and see if it wheelies on leaving the clutch lever suddenly.

**ashwinprakas** · 07-17-2012, 09:30 PM

Don't sell the fz if your riding mainly within city limits. Fz has a better mid end than the zma and will benefit you in tightly packed traffic situations.

And Comparing the suzuki the zma feels more planted cause the suzuki feels abit taller than usual bikes.

Sent from my SGY.

**ashwinprakas** · 07-17-2012, 09:41 PM

Originally posted by sunny_ View Post

Something similar there

May your dreams come true

Mine never did even in 3.7 seconds of all the time I tried to measure

All the best to your mods again

What FE are you getting during these experiments btw?

Fe took a massive hit and today when checked was around 43kmpl.

Originally posted by SriramEfunds View Post

I curious to know as to why we are doing speed checks here. Also, it doesn't make sense for a touring bike to expect a whole lot.

Just to check the condition ogre the ride. Nothing ill intended.

I'm planning to upjet with 130MJ, this will be purely for touring purpose. Thanks to Aneesh.

Anything above 127.5 on stock intake you'll kill the performance.

Still running on single throttle cable!

That's better. Abit more smoother.

Sent from my SGY.

**SriramEfunds** · 07-17-2012, 10:16 PM

Originally posted by ashwinprakas View Post

Anything above 127.5 on stock intake you'll kill the performance.

Tried to reach you. Nevermind. Here you go. If you say it would kill the performance, can you elaborate? I'm sure there cannot be very narrow window for changes.

**ashwinprakas** · 07-17-2012, 11:37 PM

Originally posted by SriramEfunds View Post

Tried to reach you.

Apologies sir, I dont use that number when am out of the house. I've texted you my main number, I'll have it with me at all times of the day. And BTW you have a weird Hello Tune.

Nevermind. Here you go. If you say it would kill the performance, can you elaborate? I'm sure there cannot be very narrow window for changes.

The ZMA is tuned to be in a very lean state from factory, but mess with the jetting even a bit and it'd be hopelessly rich. The stock jetting is perfect for the job, HECK! I use a FFF and still 130mains are making my ride surge post 5k rpm.

**SriramEfunds** · 07-17-2012, 11:58 PM

Originally posted by ashwinprakas View Post

And BTW you have a weird Hello Tune.

That's AC/DC. It's too far from you.

The ZMA is tuned to be in a very lean state from factory, but mess with the jetting even a bit and it'd be hopelessly rich. The stock jetting is perfect for the job, HECK! I use a FFF and still 130mains are making my ride surge post 5k rpm.

Did you play with AFR? Ok, what size are you running currently?

@Arun (ACS)- Did you modify the carb in your recent revamp?

Somewhere i read that they had rejetted and would like to know how it worked!

**acs1207** · 07-18-2012, 12:28 AM

Originally posted by SriramEfunds View Post

That's AC/DC. It's too far from you.

Did you play with AFR? Ok, what size are you running currently?
@Arun (ACS)- Did you modify the carb in your recent revamp?
Somewhere i read that they had rejetted and would like to know how it worked!

Nope . Left it stock since I didn't want to change too many things at once . Thought I'd get accustomed to the change in power which came from the bigger bore first . Well , now that the rains are here I'm waiting for it to be over .
AFAIK re jetting too much would be overkill if the rest is OE .

Have fine tuned my front brake and hav put in the 'B' cable today . BTW , I too have that front fork plating worn off in my bike . Guess it'll be due to regular front brake usage - since it happened in the front region of the fork tube . The local mech said that nothing can be done to cure that and I think i'll let it be as long as it doesn't leak . Once it starts leaking leaving more than a thin film , I'll change the tube .

**ashwinprakas** · 07-18-2012, 12:37 AM

Originally posted by SriramEfunds View Post

Did you play with AFR? Ok, what size are you running currently?

AFR @ 5 Turns, Acceleration at idle is rich beyond hope, bike starts easy, and sometimes without choke, but doesnt idle properly, post 5k the acceleration is awesome, but it surges, thus rendering the bike less maneuverable. Didnt have this issue with 125mains, anyways will upjet to 140Mains, just to satisfy my curiosity, and will post the results tomorrow. Also bought a few longer screw drivers, planning to have a crack at the carb head one more time.

BTW this is the resonator, removing it will make the bike abit lean and might help you with compensating for the 130 mains, but first try without upjetting, if you feel the acceleration bump is apt and the engines not heating up then keep it like that else continue with upjetting.

Loosen the clamp and pull it out. Put a cover over the hole and tighten the clamp.

**psr** · 07-18-2012, 01:07 AM

Originally posted by ashwinprakas View Post

The ZMA is tuned to be in a very lean state from factory, but mess with the jetting even a bit and it'd be hopelessly rich. The stock jetting is perfect for the job, HECK! I use a FFF and still 130mains are making my ride surge post 5k rpm.

Originally posted by ashwinprakas View Post

AFR @ 5 Turns, Acceleration at idle is rich beyond hope, bike starts easy, and sometimes without choke, but doesnt idle properly, post 5k the acceleration is awesome, but it surges, thus rendering the bike less maneuverable. Didnt have this issue with 125mains, anyways will upjet to 140Mains, just to satisfy my curiosity, and will post the results tomorrow. Also bought a few longer screw drivers, planning to have a crack at the carb head one more time.

BTW this is the resonator, removing it will make the bike abit lean and might help you with compensating for the 130 mains, but first try without upjetting, if you feel the acceleration bump is apt and the engines not heating up then keep it like that else continue with upjetting.

Loosen the clamp and pull it out. Put a cover over the hole and tighten the clamp.

It is good you have started learning about carburetors,and jetting....it is not a simple thing,though many speak of upjetting and getting X amount of Bhp....

happy to see few trying their luck too..
I do see that you have Understood the Resonator's function too...

Good Luck to you..and your bike....

**ashwinprakas** · 07-18-2012, 02:18 AM

Originally posted by psr View Post

I do see that you have Understood the Resonator's function too...

Good Luck to you..and your bike....

Sir, i believe the resonator to be the thing which reduces the turbulence in intake, some say it acts as the torque induction thingi used in 2T. And ultimately wiki makes me believe that it has something to do with the intake sound. Sir can you clear my doubt. I still have the resonator attached to the bike.

Sent from my SGY.

**psr** · 07-18-2012, 10:21 AM

Originally posted by ashwinprakas View Post

Sir, i believe the resonator to be the thing which reduces the turbulence in intake, some say it acts as the torque induction thingi used in 2T. And ultimately wiki makes me believe that it has something to do with the intake sound. Sir can you clear my doubt. I still have the resonator attached to the bike.
Sent from my SGY.

If you know Acoustics then you would understand the Resonator's role...The Japanese were the first to implement the resonator in the inlet and exhaust in commercial vehicles, though it is the invention of German Hermann von Helmholtz , and the Resonator is called a Helmholtz resonator.....it prevents standing waves ,and also acts as a pump at specific resonant frequency,and aids in better flow...
He is also the inventor of the Opthalmascope ,an instrument used to examine the inside of the eye.

**Aneesh@4GHz** · 07-18-2012, 10:22 AM

Originally posted by psr View Post

If you know Acoustics then you would understand the Resonator's role...The Japanese were the first to implement the resonator in the inlet and exhaust in commercial vehicle, though it is the invention of German Hermann von Helmholtz , and the Resonator is called a Helmholtz resonator.....it prevents standing waves and aids in better flow...

Sir does it helps in reducing engine intake noise?

Sent from my Computer.

**psr** · 07-18-2012, 10:30 AM

Originally posted by Aneesh@4GHz View Post

Sir does it helps in reducing engine intake noise?
Sent from my Computer.

Yes by canceling standing waves,and acting as an air pump at specific RPMs ,...specific to resonant frequency of the resonator, the Resonator acts as a mini turbo,at it's resonant tuning.

**Aneesh@4GHz** · 07-18-2012, 10:33 AM

Originally posted by psr View Post

Yes by canceling standing waves,and acting as an air pump at specific RPMs ,...specific to resonant frequency of the resonator, the Resonator acts as a mini turbo,at it's resonant tuning.

OK,Thanks sir,This is enough for my doubt.

**psr** · 07-18-2012, 10:43 AM

Helmholtz Resonators in the inlet improves the Volumetric efficiency of the engine...The volumetric efficiency of an IC engine is the ratio of the volume of air fuel mixture (or air) entered into the combustion cylinder to the volume of the cylinder when the piston is at bottom dead center. The volumetric efficiency is directly related to the torque output of the engine. Turbocharged engines can easily achieve a volumetric efficiency over 100%. For naturally aspirated engines, higher volumetric efficiency is achieved by using resonators integrated with the inlet manifold design....
Here is how it works...
As the air (or any gas) tries to ram into the resonator through its neck, the pressure inside the cavity increases and the air bounces out, but while bouncing out quickly due to inertia, it creates a partial vacuum near the neck of the resonator and the air is again sucked in. The process continues like the phenomena of a ping-pong ball hitting the ground. The resonator acts like a shock absorber for the pressure waves. The frequency of a resonator can be calculated as below:

Frequency f = (c/2Π).√ (A/L.V)
Where,
c = the speed of sound.
L = length of the neck
A = area of the neck
V = cavity volume of the resonator
How the Resonator can improve Volumetric Efficiency

In an IC engine, air or the air-fuel mixture is sucked inside the cylinder while the piston is moving toward bottom dead centre (BDC).
As the filling process progresses, the charge air gains more and more momentum, so the speed of the charge air increases gradually.
As soon as the piston reaches BDC, suddenly the inlet valve closes. But, the air in the inlet manifold still has a substantial amount of velocity (or dynamic pressure).
Eventually, the flowing charge air hits the closed valve, and the pressure of the charge air at the vicinity of the valve increases. The pressure wave bounces back and starts moving toward the opposite direction.
If a resonator is attached with the inlet manifold, then it will act like a spring to the just-created pressure wave.
The frequency of the resonator determines the speed at which the pressure wave will proceed again toward the inlet valve.
If the frequency of the resonator and the speed of the engine (which determines the interval between the opening and closing of the inlet valve) are properly tuned, the pressure wave will hit the inlet valve again at the time when the inlet valve is open. This phenomenon will cause a rush of charge air into the cylinder. The charge air will be forced into the cylinder, causing the increase in volumetric efficiency.
The point to be noted here is that you will get maximum benefits of increased volumetric efficiency only if the engine running frequency and the resonator frequency are properly tuned. That means you can get maximum benefit only for a particular engine operating speed with a fixed frequency resonator.
For selecting a resonator, the engine operating speed, intake manifold design, and volume of the intake manifold need to be considered. Roughly, the resonator frequency is kept around double the engine frequency in order to get the benefit of the volumetric efficiency increment.

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