how to adjust air fuel ratio

[alvin2002_my]

not same.... there is 2 separate screw to control it....

bro, wanna ask u something..
currently im driving iswara 1.5, 1993, having a MC..
im thinking of tuning the A/F ratio myself.


8)Continue to turn out the A/F screw at half turns every 3 seconds. Engine will pick up speed. Continue to screw out until the point engine runs worse. When that happens screw back in half turn every 3 secs to the point engine runs smoothest.(do this by ear or watch engine vibration)


on step 8,
can it be listen by sound?

how to know whether the engine run worse?

how we going to know the car is running smoothest? is there any tips?


thanks bro..

 

[SkYwAlKeR]

yes, can listen by sound... but this takes experience and knowledge....
leaning out the afr, ur engine will jerk and vibrate (as if rpm drops alot).... turn it out (rich) abit to make it smooth.... den go test drive... find the best AFR ratio for the performance u want.... coz lean afr, performance decrease.... rich afr, increase performance.... but too rich, performance will drop and fc will increase.... too lean, might cause detonation and burn ur piston....

 

[azuaneman]

SkYwAlKeR: this one can use for tune ka :D
DIY monitoring a/f
i'm wanted to do this one but seem dun hav gadget ...

 

[burnner]

yeah...after tune, must go for test drive,
instatly you can feel the diffrent,
adjust to your taste...
did mine few months ago....
now need to retune back....
very simple and easy if you did it few times already...

 

[alvin2002_my]

yes, can listen by sound... but this takes experience and knowledge....
leaning out the afr, ur engine will jerk and vibrate (as if rpm drops alot).... turn it out (rich) abit to make it smooth.... den go test drive... find the best AFR ratio for the performance u want.... coz lean afr, performance decrease.... rich afr, increase performance.... but too rich, performance will drop and fc will increase.... too lean, might cause detonation and burn ur piston....

is there any indication when it's too rich?:_:

 

[SkYwAlKeR]

SkYwAlKeR: this one can use for tune ka :D
DIY monitoring a/f
i'm wanted to do this one but seem dun hav gadget ...

i've read about this too... but u still need a O2 sensor at ur exhaust.... normal sensors are narrowband sensors, they do not give accurate reading... even if u wired a AFR guage directly to the sensor, the reading might not be vr accurate... u still need to test drive around and monitor it closely....

wideband sensor is the best choice.... but with a price tag of rm1XXX, i prefer learning to tune AFR the hard way (through experience)....

is there any indication when it's too rich?

jeng jeng jeng...

if u lazy to remove ur plugs, can check ur exhaust fumes... if got heavy unburn fuel smell, means running rich... if black smoke come out, AFR vr rich....
optimum would have water vapour emmiting from ur exhaust... can use ur palm to test....

PS: dun smell too much la... later can get vr "high"....:regular_smile:

 

[azuaneman]

i though mostly Japanese's car got O2 at their extractor, for EFI version..

 

[alvin2002_my]

i've read about this too... but u still need a O2 sensor at ur exhaust.... normal sensors are narrowband sensors, they do not give accurate reading... even if u wired a AFR guage directly to the sensor, the reading might not be vr accurate... u still need to test drive around and monitor it closely....

wideband sensor is the best choice.... but with a price tag of rm1XXX, i prefer learning to tune AFR the hard way (through experience)....


jeng jeng jeng...

if u lazy to remove ur plugs, can check ur exhaust fumes... if got heavy unburn fuel smell, means running rich... if black smoke come out, AFR vr rich....
optimum would have water vapour emmiting from ur exhaust... can use ur palm to test....

PS: dun smell too much la... later can get vr "high"....:regular_smile:

oh..ok
thanks bro..
will try it later..
thanks ya...:_:

 

[SkYwAlKeR]

i though mostly Japanese's car got O2 at their extractor, for EFI version..

yealer.... but now we talking about carburetor engine AFR tuning mah.... carburetored engine where got O2 sensor ler....

 

[mivec4g63T]

i found the screw.. but dunno y the screw is too tight, unable to turn by hand, any toolkit to turn it? or i nit to apply WD-40, oso the screw is excessive hot when i touch it on engine running.

 

[SkYwAlKeR]

u need a specially modded sparkplug to turn it... it is designed so so that one wont simply turn it for fun and mess up the A/F ratio....

 

[mivec4g63T]

where can i buy the sparkplug to DIY it? i think my carb is mistuning now..
gas from the the exhaust is dense of petrol smell. the car suck petrol like water and run no smooth..

 

[SkYwAlKeR]

no need to buy lar... no ppl sell also... find any old unwanted sparkplug and mod it urself lor....

 

[Noob]

Any sifus out there has the picture of the modified spark plug? located the screw but had no idea how to screw it..

Appreciate the help guys!

 

[SkYwAlKeR]

jeng jeng jeng...