Carburetor Upgrade & Free Flow Air Filter

Thanks for the initial inputs mate.

Anyways if you don't mind i would try put it up in simple Noob friendly terms.

The stock Carburetor Mikuni BS 26mm has been designed specifically to provide a correct AFR (Air:Fuel Ratio) mixture to the stock 153cc engine for combustion. However, with the installation of the big bore 180cc kit, the required amount for correct combustion to take place has also increased. Look at it this way, a 10 year old trying to eat a burger compared to you eating the same sized burger, your mouth will be able to take/ prefer larger volume of the burger in a single bite compared to the 10 year old kid!!

REJETTING
The cheapest way to fulfill this requirement is Rejetting the pilot jet and the main jet specifications of the stock BS 26 carburetor. The Pilot jet and main jet control the way a thin spray of fuel is formed and then mixed with the air to provide the AFR to the combustion chamber. I hope the Noobs, you are with me till now..

So rejetting is basically changing the size of the jets to alter the way the spray and the volume of fuel will go and mix with the air to meet the requirements of the 180cc big bore kit . Although it is a temporary solution but doesn't work that great with the RC power up kits... One may find a lot of flat spots i.e sudden hiccup or no power from a certain rpm to certain rpm say 4000 - 6000 rpm and then post 6000 rpm everything is fine. Or if one is really gunning his tuned ride, the bike may feel stressed and hungry for a bit more fuel and air mixture.

The solution? One has to go for a carburetor upgrade! Now Joel provides two options for Yamaha FZ souped up ride:

*29MM CV Carburetor: The 29MM CV (Constant velocity) carburetor provides the correct fueling required by the 180cc big bore kit (i.e. big Burger, Maharaja Burger!! ). CV carbs or Constant velocity carbs in the word of mighty 'Mad Mik' , provides linear fueling to the engine i.e. the ride feels smoother and the engine will get ample amount of fueling right from the idling to the red line. Would recommend this set up for extensive touring, especially people who intend to do Leh and Ladakh kinda tours as it is easy to tune even by a local mechanic should the AFR become lean when crossing extremely high altitudes. It is also easier to maintain.

*32MM Semi Flat Racing Carburetor: There is just one way to describe this carb 'Brute power!', Semi flat carburetor has a very aggressive profile i.e. one gets a very aggressive surge of power. Very good to do drag runs, where your tuned FZ will whoop a lot of others in 0-100 kmph timings. However, i would say this carb is good for street fun/track fun only as it is finicky and may start giving one problems when one starts to climb a certain altitude. In such cases one may have to constantly tune it/ fiddle with the AFR settings.. So Noobs, if you don't do extensive touring like i do and have no intention of hitting Leh and ladakh but want to whoop the exotics and see the faces of the owners.. THIS IS IT!!

@Mik & Luke: Please do correct me if i have left out something..

Performance Free Flow Air Filter
Now Folks, why do we need to replace the stock air filter and put in a Performance Air Filter? Well The stock air filter is very good but at the same time quite restrictive with the air flow. The stock air filter will not be able to efficiently provide the correct amount of air flow required by the souped up engine.. so one will witness a drop in performance. Thus, the Performance air filter allows now the tuned up ride to breath better thus generate more power! Imagine you are trying to breath through a blanket and then try to breath through a silk handkerchief.. i hope you get the picture..

Joel, Race Concepts Provides two types of Performance Air Filters for the same

* Simota Stock replacement Air Filter: The stock replacement Simota air filter sits right in place of the stock air filter in the AIS box of your ride. Requires periodic cleaning just like you would with the stock air filter. I would highly recommend this type of filter again for tourers and riders who live in a very dusty environment.

* Simota 50MM Conical Filter: This needs to be connected directly to the carburetor. Gives much better air flow to the Carb, thus providing better atomisation of fuel and better linear power output. It is a mandatory upgrade along with the 32MM Semi Flat carb. Downside is, being exposed to the elements, the interval of cleaning is lesser then the replacement air filter. Well you can't have everything right!!

Will blabber more later..


@N-o-v-i-c-e : Please do post the series of events as requested in my earlier post. Would help a lot of readers here.

Cheers,

You are an experienced and learned rider. This is applicable for all the Noob and in-experienced riders to avoid any confusions and then stupid kit failure complaints which in most cases is incorrect installation or tune up issues.. so safe approach is a better bet for the generic riders.

Congratulations N-o-v-i-c-e, I really want to see the 0-100 figures now!! With protection and a safe road of course.

Well mate, we know you built the engine yourself and you are a vastly experienced rider...
So i must say in your case being crewed = happy rider face

cheers...

Thanks. But you gotta wait for sometime coz i dont have the right equipment for logging the 'times'.
Will post it in due course of time....

With more volume you need more air and of course the correct amount of fuel to fill the chamber. Tune is what brings out your power, the polish and shine on your black leather boots if you want.

The engine is just a air pump. More air it can suck in and pump out the more power it will have to push the piston down spinning the crank around harder and faster. If you want to reduce the power you restrict the air entering and exiting.

Just my 500 Vietnamese Dongs worth (my 2cents)

All the credit goes to my mechanic and owner at KTL Tecnic, I just bugged the hell out of him and hung around the shop like a bad smell hahaha.
He did the maths, we did mockups and found problems before they can turn into bigger ones, Come up with solutions to make it work.

My experience is with forced induction (japanese) car motors (love Toyotas) I just bring what I learnt from that side to bike engines.

Bad smell??

You'll have to wait for a bit though.. i am also in line to acquire more horses for my FZ and will also provide extensive data within my capabilities and unbiased review of the RC Kits. I am currently not in Mumbai so once, i come back will post step by step installation pics as i start my RC build and expert advises on the same which unfortunately N-o-v-i-c-e missed out.

Good or bad reviews, the whole agenda of keeping this thread Noob friendly is to ensure that 'Haters' don't crop up with new threads and posts... without understanding the basics about tuning, troubleshooting and steps for installation of power up kits, in this case for Yamaha FZ.

Hope everyone will make this thread lively and healthy.

Cheers,

Congrats on your ride NOVICE. Continue to break her in and ride hard. Nothing to worry. Make sure you do the fuelling and swap the jet too. YOu will find a world of a difference with the 29mm carb and the new jets that we send it with. Will improve efficiency and power drastically.
Ride safe and have fun!

@Joel: I know you are pressed for time with your developments and racing. Would request you to please do fill in few liners here on this thread whenever possible... we would like to ensure that this threads clears all the air surrounding with RC kits and in general helps others understand and look at hot roding in a new perspective.

Cheers,

@ Joel

Please reply to my email. I'm waiting for your reply.

Thanks buddy. I intend to break-in and ride hard come what may. The jet's been swapped. Just the nitty-gritty tuning has been going on.

I second that...do keep posting here.

Today, a strange thing happened. The flat spots being observed earlier at 2-3k and then later on at 6-7k rpm had changed.

Now the bike feels slow at 2-4k rpm. But then onwards there's no time to look at the rpm meter before you crrash into someone.

More tuning to be done tomorrow..

cheers...

Ensure that you are gentle with her for some kms.. unless you intend to use motoman technique.. I am not gung ho for it.. i would say follow the stock run in method..


Cheers,

Hey NOVICE what's the update. You didn't even tell us the mileage with the stock re-jetting and also what's the ODO now. Can't see three people who have modded the bike, the people are Duoscribe, Sydney C and rylan. With such a heated discussion going on I hope these two guys turn up and share their status about the modded babes

Don't be too gentle unless you want to glaze up the bore.
If you let it warm up, then ride it "normally" as per traffic you should be fine, Don't go ripping it in traffic, time and a place for that.