how to adjust air fuel ratio

[olcheong]

anyone can tell me how to adjust the air fuel ratio of 4G15 carb?my car geting only 250km for Rm 50 Fuel :'( too bad fuel consumtion...pls giv me a guide on it thnx ya

 

[SkYwAlKeR]

1) Warm up engine first(run 5-10 mins)
2)Shut off engine
3) Back out on the idle speed screw until it justt doesn't touch the throttle linkage. Then screw it in back about 11 turns
4) Screw in the A/F mixture screw until it stops(do not force tighten)
5) Screw out the A/F mixture screw 2 full turns
6) Start the damn car. It will run like its choking. As long as it's running it's ok.
7) Now turn in the A/F screw until engine dies. If this happens, turn out the A.F screw half turn at a time to bring it back. (try to start the car of coz)
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)
9) Now set the idle speed. Go on the air conditioner. Watch the tachometer. Turn in the idle speed screw until rpm is around 900 to 1000 rpm.
10) Now it's ready to rumble..

 

[vastalux]

can this method use for injection engine??

sori for noob qeustion...

 

[xtorm]

no......

tat is for cab only :)

 

[burnner]

hey olcheong,
give us the result after had tune up.

 

[kudisbute]

Is it can apply to any type of carb bcoz i want to try also n i run with ford 1.8 carb

 

[SkYwAlKeR]

Is it can apply to any type of carb bcoz i want to try also n i run with ford 1.8 carb

i dun think so... because certain carbs have separate knob/screw for air and fuel...

 

[kudisbute]

My car also have one screw for air/fuel ....

 

[papagoines]

1) Warm up engine first(run 5-10 mins)
2)Shut off engine
3) Back out on the idle speed screw until it justt doesn't touch the throttle linkage. Then screw it in back about 11 turns
4) Screw in the A/F mixture screw until it stops(do not force tighten)
5) Screw out the A/F mixture screw 2 full turns
6) Start the damn car. It will run like its choking. As long as it's running it's ok.
7) Now turn in the A/F screw until engine dies. If this happens, turn out the A.F screw half turn at a time to bring it back. (try to start the car of coz)
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)
9) Now set the idle speed. Go on the air conditioner. Watch the tachometer. Turn in the idle speed screw until rpm is around 900 to 1000 rpm.
10) Now it's ready to rumble..

Sir Skywalker... I'm noob to carbs

1. 4G15 for Iswara Auto, izzit the same???
2. Is there any illustrations for the screws location?
3. If I can ask somebody to show me where the screws are, does the term screw in meaning clockwise and vice versa?
4. OK...if I'm a total loser and can't tune the carb meself, how much does it cost to tune it? For that matter, what are the total cost of giving the carbs a full service?

I;m asking this because the mentioned Iswara belongs to my dear mom. I can't bear it to her complained about FC anymore...thanks

Sorry for sooo many stupid questions....

If you wanna know, I'm using Kancil 850Ezi ('i' means injections) as my first and current car...so I'm really 'jahil' abt carbs....

 

[SkYwAlKeR]

Sir Skywalker... I'm noob to carbs

1. 4G15 for Iswara Auto, izzit the same???
2. Is there any illustrations for the screws location?
3. If I can ask somebody to show me where the screws are, does the term screw in meaning clockwise and vice versa?
4. OK...if I'm a total loser and can't tune the carb meself, how much does it cost to tune it? For that matter, what are the total cost of giving the carbs a full service?

I;m asking this because the mentioned Iswara belongs to my dear mom. I can't bear it to her complained about FC anymore...thanks

Sorry for sooo many stupid questions....

If you wanna know, I'm using Kancil 850Ezi ('i' means injections) as my first and current car...so I'm really 'jahil' abt carbs....

1) yes.... 4g15 n 4g13 using the same carb....

2) jeng jeng jeng...
http://img112.imageshack.us/img112/2594/screwsqr2.jpg

3) screw in means clockwise... similar to water pipe... wanna close the tap (lean mixture), u turn clockwise....

4) the workshop usually tune my carb and ignition timing only charge me 5bucks... other workshop i dunno... but shouldnt be expensive....

 

[ken12292703]

1) yes.... 4g15 n 4g13 using the same carb....

2) jeng jeng jeng...
http://img112.imageshack.us/img112/2594/screwsqr2.jpg

3) screw in means clockwise... similar to water pipe... wanna close the tap (lean mixture), u turn clockwise....

4) the workshop usually tune my carb and ignition timing only charge me 5bucks... other workshop i dunno... but shouldnt be expensive....

Jeng Jeng Jeng... The sifu showing his weapons... FU YOH!

Good information bro... Will the AFR change after some time? Vibration and stuff?

 

[SkYwAlKeR]

in normal condition, vr seldom the tuning will run... ur AFR usually getting richer because of ur clogged air filter....

thats also why some installed microcompressor said got difference.... this is because the leaked air in bypassed straight into the intake manifold, thus balance back the rich AFR....

 

[burnner]

good stufff...

 

[papagoines]

1) yes.... 4g15 n 4g13 using the same carb....

2) jeng jeng jeng...
http://img112.imageshack.us/img112/2594/screwsqr2.jpg

3) screw in means clockwise... similar to water pipe... wanna close the tap (lean mixture), u turn clockwise....

4) the workshop usually tune my carb and ignition timing only charge me 5bucks... other workshop i dunno... but shouldnt be expensive....

A thousand thanks......will do it if got time...if not I can just ask mom to send the car to workshop if the pricing like u sez....
now the car at my kampung...

one question thought....
idle speed screw = air con off idle screw?

thanks a mill...especially for the picts...

 

[SkYwAlKeR]

one question thought....
idle speed screw = air con off idle screw?

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

 

[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
http://autospeed.drive.com.au/cms/A_0217/article.html
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?:_: