air filter racing tu macamana ?

How good is your FC? Can you share?
Fuel screw means, the more you open, the more petrol.
For you, to open another 1.5 turn is too rich already. Normally, after you get the max RPM, is richen a little bit, that's even less than 1/8 turn.
For carb setting, even 1/8 a turn is considered sensitive. In my case, after setting done, I mark the pilot screw to check next time if setting go off.

Yes, for BS carb, as it is sensitive to air filter change.

For cold start, you need to richen the AFmix, that's why you have a choke. So, the bold parts in your quote is incorrect.

Rich and lean does affect the plug life, but that's not the right way of putting it, because when the plug already dead, most likely the engine, too. Practically speaking, it is the other way around: The plug has to be 'hot enough' to clean itself, and reading the plug can tell you if you are running rich or lean.

You change to 28mm manifold, and does it taper open? Or, is it 28mm all the way to silencer?
If it tapers open, better torque for low-mid RPM only, but if 28mm all the way, no torque at low RPM, peaky engine.
Better change everytime.

Juz curious.. use wat to wash? Petrol?

thanks bro for the detail explanations.

now i understand that choke means to richen the fuel mixture by choking the air.
so, my max RPM i can hear is starting from 3.5 turns and above until 6 turns. after that it will get low again since fuel is more than the air. is it the best for my FUEL SCREW setting is at 3.5 turns only ? not 5 turns ?
i need to know which is the optimal setting for my fuel screw with KNN air filter installed first, after that i will check my spark plug condition later.
BTW bro alexei, i am a little bit confuse here since some people said i need to set the idling engine at 1100-1550rpm before setting the fuel screw, and some said i need to put engine idling rpm to 2500-3500 rpm first before setting the fuel screw. which one is the best method for mikuni bs25 carburetor ?




these picture is my guide later.

bro alexei, about the exhaust, it was 28mm manifold with standard muffler same design as stock. better sound than stock exhaust. but not too loud

This post has been edited by piju: May 12 2014, 03:47 PM

The fuel setting goes like this, lean -> ideal -> rich.
Only when over-rich it will bog down the engine, so, I would say start with 3.5 turn, and add another 1~2 minutes of a turn. This will only affect idle and 1/4th of the BS carb, which is something you can't tell. You will have to feel the engine response from off idle (slightly opening throttle) all the way to cruising speed.

Idling just need to set higher than normal during carb tune. If 2.5~3.5k RPM, that might reach the jet needle setting range already.
Once you get the pilot fuel screw correct, and notice cruising steady at quarter to half throttle is not good, then you adjust the jet needle.
After that, test half throttle to full throttle, look for flat spot, and adjust mainjet.

With the 28mm manifold, you might need to tune mainjet later. But, don't worry too much, figure out the pilot fuel screw first.

My RGV plug reads between 'good' to 'best' now. For a 2 stroke to read a clean plug like that, took me a long time.
Perhaps later I open it and have a look again, it's been a while.
My journey took me through setting the pilot air screw, dropping the jet needle, reducing mainjet twice, and set the pilot air screw again until satisfied.

Now, FC is city @ 170~180km, highway @ 280km per 4.9 liter petrol.

what do you mean with "add another 1~2 minutes of a turn" ?

thanks for explanations again bro. actually my primary intention was to find the good optimal setting for fuel screw only. i am not planning to reposition jet needle now. maybe later.

and i understood what you tried to say, it is like after tuning the fuel screw, i need to drive my bike and feel the acceleration by trying all degrees of throttle positions.
right bro alexei?

piju1~2 minutes of a turn, expressed like a clock face, a small amount of turn. Example, if 5 minutes would be like 1/12 of a turn.

Yes, experience the acceleration by slowly twisting the throttle. If there is a bog or hesitant, tune again... until satisfied.

For plug reading, refer to this: http://www.4secondsflat.com/Spark_plug_reading.html

Bro Alexei,

Reporting FC on 177 cc or 62mm shark block, 2nd used by thianz
http://www.fuelly.com/driver/etks2011/lc135-36

Thianz,

Finally done...how to pay u for the block and return another block...

Findings on Tires

I found that the Duro Taiwan which has biji- biji at side

1) Nearing safety tire limit, feel like the tire puncture or will lari a bit a rear, size 80/90...

2) for front 70/90, I reach GPS speed at above 132km/h the tire start shake and feel float....I wonder is the tire limit, but when put at rear also same issue, so this Brand Tire not suitable for ppl going for high speed..

Corsa 80/90 Tires is abit more expensive than duro but it seems tat the rubber is thicker...

I need to re calibrate my Koso Meter to 99% last time setting for duro 80/90 is not mistaken is 101%...

Almost slip also with Duro Taiwan front 70/90....

Now setup front Corsa 80/90 and rear Duro Taiwan 70/90...just 1 use finish the tire and measure FC difference on rear 70/90...no difference, put back 80/90...This shud be enuf grip for 62mm...

NewGUYThat fuelly profile is you? I added as fuelly friend now. My RGV FC seems better, using 70/90 and 80/90 tyres.

Duro with biji on side? Is it like sisik? Maybe too new to me, haven't been looking at tyres lately. Can you share pics? There are 2 commonly good one, the HF-918 that looks like Battlax BT039, and Duro RS that looks like Michelin Pilot Power.

thanks bro,
now i understand that i need to tune my carb again.

i will close the fuel screw, open it to 3.5 turns and play around with 1~2 minutes turns.
maybe i need to open or close more or stay at 3.5 turns right bro alexei?
however, i need to set and play with the throttle first. different bikes and riders may comes with different result i think.

btw, bro. which is the best way to increase RPM ? is it by turning the idle screw or just twisting throttle using hand ?

This post has been edited by piju: May 14 2014, 03:02 PM

Start again from 1 turn onwards, until the max RPM. Then, open another 2~3 minutes, just so slightly.
Idle RPM is adjusted with idle screw.

btw bro alexei, quoting your previous reply. you said "normally after you get the max RPM, is richen a little bit",
so, im here asking why do we need to open 2~3 minutes more ?

piju I guess is for protection, when during cooler days, from running to lean.

after oil replacement at 500km, it fell like hard to start need to tune again... is it normal?

yes.

i see, thanks for the info.
just now i set my fuel screw to 3.5 turns and added 2~3 minutes more. idle RPM quite good. throttle respons also good. but when i ride the bike and feel like some bog and hesitant happened when the bike is high RPM on gear 2, after i shift it to gear 3 then it's ok. is this happen because im using high flow air filter?

(i assume than when higher rpm, the combustion chamber will produce more pressure to suck the air and since im using high flow air filter, the air will enter more than fuel, this is why bog and hesitant happened)

If you think is high RPM, then perhaps need to kacau needle. Before you do that, try with pilot screw open and close quarter turn extra from default 3.5 turns.
At different throttle opening, the AF ratio changes. So, after air filter change, you need to readjust the whole carb circuits... not just pilot screw.

Sisik or biji biji like maxxis, shop seller say is duro taiwan...

Erm, what does the tyre sidewall printed?
Got brand, model number, 'Made in Taiwan' or 'Duro RS' printed or not?