not necessary. The factory fuel-map is optimized for emission, to protect engine from overheating and durability. Usually they go for rich settings at big throttle high rpm, that's why standard bike feels heavy when rev gets higher (exhaust also part of the contribution). They gotta assume worst case condition such as a rider always go full throttle at top rpm for 1 freaking hour. So to prevent that happen, they increase the fuel to AFR about 12.x or even worse (such as 11.x or 10.x). The implementation is manufacturer specific, not standard across everyone.

For air-fuel tuning, the most important factor is know our own riding style. If a guy always like to open big throttle, decreasing mainjet is a good option, but the problem is higher engine heat which decrease durability although FC is better. Personally I seldom open full throttle unless necessary. So jet needle will go lean (to get good mileage at cruising speed), but mainjet i'll go rich to have the burst of power when accelerating. Once accelerate to 60km/h quickly, i can keep the longest time possible to use the slightly lean jet needle setting.

This one no shop can tune for me, as most of them usually go for best power (for manufacturer usuallyl best durability). So, self tuning is the best way to optimize setting for own riding style. Heck, even F1 cars have on-the-fly air-fuel selector on the steering wheel to have some minor tuning by the driver himself.

one thing to note, air-fuel tuning gotta be done when the engine is warmed up, and depends on your riding distance. For ex, i ride to work about 7km distance everyday. Usually i make it more lean as the engine cant fully warm up with such a short distance. When travelling more than 20km (or need some power run such as full throttle), I'd tune it richer --> first few km engine will feel heavy due to rich setting, after tat gets better and better. up to ful warmed up phase, the air-fuel will be just nice.

This post has been edited by charge-n-go: Apr 26 2015, 01:21 AM

Quoted below.

This post has been edited by alexei: Apr 28 2015, 04:40 PM

alexei bro, 7 - 10 usually use in turbo application. For carburetor, anything less than 12.8 won't make extra power (that's from a simulator software I used to mess around). In real life, I had no idea how the AFR of 135LC really is, need to go through dyno baru tau. For accel pump, it is use to deal with the sudden change of increased air mass, so that AFR wont go too low out of sudden.

in this case, a well tuned FI really shines in term of power and FC.

yeah,i'm finally back after long time mia wit a sad news which i got involve accident on my LC wit toyota altis~
damages on my bike is broken coverset,footrest,gear lever,both side mirrors,handlebar n my headlamp needs replacement n luckily aunty's daughter willing to pay full ammount on my bike~ huhuhu~

As long as you're ok, then worry about the bike... ada gambar?

got but a bitlazy to post it up~

This forum allow upload pictures...

it's ok ba,i'm jus lazt only~

Yeah, you can add attachment. If it is an image, it will show up as thumbnail at the bottom of the post.
Example of imaged added to post:
[attachmentid=4431588]

Example of thumbnail:

situation: let's say i am in 5th gear and need to drop 2 gears into 3rd

what i have been doing:
1. clutch in
2. downshift to 4th gear
3. rev match/ throttle blip
4. downshift to 3rd gear
5. rev match/ throttle blip
6. clutch out

but recently, what i did was:
1. clutch in
2. downshift to 4th gear and rev match/ throttle blip simultaneously
3. downshift to 3rd gear and rev match/ throttle blip simultaneously
4. clutch out

i have tried the following steps but my ride wasn't smooth :
1. clutch in
2. downshift to 4th gear and rev match/ throttle blip simultaneously
3. clutch out
4. clutch in
5. downshift to 3rd gear and rev match/ throttle blip simultaneously
6. clutch out

will my recent 'behavior' give harm to my gearbox later? what is the best way for downshifting gears?

This post has been edited by cahayamalamku: May 5 2015, 11:02 AM

I have read your post, and I can imagine myself down shifting but only throttle blip before engaging the clutch.
Wait for other sifu to comment.

IMO, not engaging the clutch is fine, if not a better practice.

1st .. apa sebab u mau drop 2 gear ???? masuk corner ? nak slow down ? ayam kompius .......

contoh .. u sebelum naik bukit ..... 100km/h .... tak kan u nak drop 2 gear terus .... pastu nak pecut naik bukit ? confirm .... tak semut la .....u drop 5 > 4 ... rpm will naik sikit .... 4 > 3 lagi naik rpm .... pastu u feel tertarik dah ...... itu masa u throttle balik maintain ur speed around 60+ i think ..... naik bukit ...

(kecuali anda pakai sprocket kecil daripada std kilang anda buli drop 2 gigi terus throttle naik buket ... )

1. naik bukit then need to masuk simpang at left which has higher bukit
2. sudden brake when car changing lane without signals
3. making fast u-turn
4. going through hump at high speed

hai otai n sifu skalian..
adik newb nak tanye ni..

sy pakai cam cms, blok ikk..lpas pasang dulu bunyi kat cam tik3 je,bunyi stended cms.. tp skrg dah bunyi tak3..kuat jgk bunyi nye..kalau camni, ape problem nye eh? cam makan head ke acane?

mohon pencerahan..

Biasa cam haus, sbab exhaust port overheat sampai tapet minyak kering...

drop jer la ... terus pecut

ni pasang ada set tepet ke tidak ? blok ikk size apa ? takut valve langgar piston jer ..

..100cc bike nak laju laju gi mana

Later faster than your bike then you know.

biar jer ... xkisah ... janji selamat

speedo 140 .. pun tak sampai 140 pun

rantai motor berkarat lah.. nak buat macam mane.. spray wd-40 boleh ke?

ekzos pon berkarat..jatuh seret jalan licin.. spray balik ke mcm mane..

tq