For DIYourselfers only:Paano kayo Mag-adjust ng carburetor?

[ese]

Mga DIY na pare ko, Paano ba mag-adjust ng carburetor? Marami na akong napuntahan mga website about carb adj. pero parang iba-iba rin ang ang suggestions nila. Share nyo naman ang method ninyo. Thanks...

[wildthing]

There is one I learned on carb adjustment...."IF IT AINT BROKE, DONT FIX"

Most often the problem is not the carb adjustment (nozzles and jet)...Usually its one of these:

1) Unlubricated pivots or springs - sol'n->spray liberal quantities of WD40
2) Unlubricated cable - sol'n ->pull out the cable from the cable housing and lubricate with grease and slide it back into the cable housing and reinstall.
3) Dirty carb nozzles - sol'n -> if you have money buy a canister of the carb cleaner and follow instructions of use. If you don't have money, brush the carb with fuel as solvent...do this while engine is running so you could "force" some air para mahigop ang mga dumi na nadissolve.
4) Dirty fuel filter - sol'n -> replace lang ang option.
5) Baradong fuel line - sol'n -> general cleanup ng fuel line and the fuel tank na rin. After this chances are you'll need to replace the fuel filter din.

If it is not one of the above mentioned cases, this is what I do:

(Subject: Carb of a nissan A12 engine of a nissan sunny pickup, 91 model)

1) I make sure my timing is right....so tune it up first....
2) Run the engine
3) I slowly "open" the adjustment screw until the engine nears choking (die of too much fuel)....this is your theoretical "rich" setting
4) From there, I would "close" the adjustment screw...carefully counting the number of turns until the before the engine die due to lack of fuel...this is your theoretical "lean" setting
5) (Usually the engine dies) so before I restart the engine I would turn back the adjustment screw to "open" but only 3/4th the number of turns before it reach the "rich" setting. This is the theoretical "correct air/fuel" mixture or what they call yata stoich (correct me if I am wrong).

That's it. That method more or less work for me on that type of engine. If you ask me why "3/4th the number of turns", for me it is because...the "lean" setting is 16:1 and the "rich" 13:1 and the stoich is 14:1 ... so theoretically 14th is about 3/4th the way back going to the 13:1 from the 16:1.....did I confused you more???

My 2 cents, Peace.

I am very open for other suggestions.

[jtdc]

thanks wildthing, will check on this matter w/ the mechanic who will overhaul my carb.

[empy]

Originally posted by wildthing
1) I make sure my timing is right....so tune it up first....
2) Run the engine
3) I slowly "open" the adjustment screw until the engine nears choking (die of too much fuel)....this is your theoretical "rich" setting
4) From there, I would "close" the adjustment screw...carefully counting the number of turns until the before the engine die due to lack of fuel...this is your theoretical "lean" setting
5) (Usually the engine dies) so before I restart the engine I would turn back the adjustment screw to "open" but only 3/4th the number of turns before it reach the "rich" setting. This is the theoretical "correct air/fuel" mixture or what they call yata stoich (correct me if I am wrong).

hahaha....ganito exactly ang tuning method ko sa nitro r/c ko...i guess a carb is a carb, huh? :D

[wildthing]

okay eto ah...nasa baul na ung thread e nahukay pa.

[afrasay]

Originally posted by wildthing
There is one I learned on carb adjustment...."IF IT AINT BROKE, DONT FIX"

Most often the problem is not the carb adjustment (nozzles and jet)...Usually its one of these:

1) Unlubricated pivots or springs - sol'n->spray liberal quantities of WD40
2) Unlubricated cable - sol'n ->pull out the cable from the cable housing and lubricate with grease and slide it back into the cable housing and reinstall.
3) Dirty carb nozzles - sol'n -> if you have money buy a canister of the carb cleaner and follow instructions of use. If you don't have money, brush the carb with fuel as solvent...do this while engine is running so you could "force" some air para mahigop ang mga dumi na nadissolve.
4) Dirty fuel filter - sol'n -> replace lang ang option.
5) Baradong fuel line - sol'n -> general cleanup ng fuel line and the fuel tank na rin. After this chances are you'll need to replace the fuel filter din.

If it is not one of the above mentioned cases, this is what I do:

(Subject: Carb of a nissan A12 engine of a nissan sunny pickup, 91 model)

1) I make sure my timing is right....so tune it up first....
2) Run the engine
3) I slowly "open" the adjustment screw until the engine nears choking (die of too much fuel)....this is your theoretical "rich" setting
4) From there, I would "close" the adjustment screw...carefully counting the number of turns until the before the engine die due to lack of fuel...this is your theoretical "lean" setting
5) (Usually the engine dies) so before I restart the engine I would turn back the adjustment screw to "open" but only 3/4th the number of turns before it reach the "rich" setting. This is the theoretical "correct air/fuel" mixture or what they call yata stoich (correct me if I am wrong).

That's it. That method more or less work for me on that type of engine. If you ask me why "3/4th the number of turns", for me it is because...the "lean" setting is 16:1 and the "rich" 13:1 and the stoich is 14:1 ... so theoretically 14th is about 3/4th the way back going to the 13:1 from the 16:1.....did I confused you more???

My 2 cents, Peace.

I am very open for other suggestions.

I'll take your word for it. ;)

[vinj]

IMO, the best is to actually watch and learn from someone who knows... What i did the last time was i just brought the car to Kamias and had a shop open it up to clean it and adjust (cost me P350). The next time around, i'll have my carb-addict friend teach me hands-on already.

[oldskul]

wildthing..but there two adjustments sa carb...yung sa hangin at fuel...paano naman yung sa hangin...same prod. ba

[tip_tipid]

oldskul, you may be referring to the throttle adjusment screw? this is for setting the idle engine rpm and does not affect the fuel
air mixture.
What i normally do is to first set the idle engine rpm to the lowest
possible setting and then try to adjust the idle fuel air mixture for
best engine performance at both ends of adjusting screw travel and settle for midway setting. This is the idle speed fuel air mixture. When the throttle is opened, the fuel air mixture is conrolled by the jets and the venturri. there is no adjustment for this.

[oldskul]

thanks tip_tipid but ur way of adjusting is different from wilthings way...or maybe it depends on the machine....

[wildthing]

oldskul,

IMO don't touch the air screw...it won't do you any good....I believe this is some sort of a breather for the fuel inside the carb reservoir and does not affect the air/fuel ratio.

The air in the a/f ratio comes through the carb opening (yung meron venturi) and filtered by the air filter. The screw I mentioned, will then control the fuel flow.

Put it this way the volume of air that passes thru will be more or less constant at idling and thus twisting the fuel screw at the right level will give it the right a/f for good idling combustion and fuel economy.

BUT when you are racing or reving the engine...its a different story...the "constant" air that passes thru the venturi will now increase because of the added "accelarating" or increasing air pull (from the inside of the engine)....if the amount of air that gets into increases then the original right a/f mixture at idling becomes LEAN (kulang ang fuel vs air)... so mahihirapan ang vechicle to cope up (does loosing power). As such, oldschool racers will tweek their fuel screw towards a RICH setting at idling (matakaw sa fuel) so that when they are in the high rev, there would be a proper a/f ratio going into the vechicle and thus give the right power.

Again...don't touch the air screw at all.....IF IT AIN'T BROKE, DON'T FIX....

just my 2 cents. Peace

[bardigones]

up ko lang.


saan ok magpalinis ng carb? pati mga gaskets and other carb thingy ipa-condition...

[napadpad_lang]

Im looking for a Nissan Sunny Carburetor- novice po here.. baka my marecommend kayo where to buy it.. yung authentic nissan parts naman sana.. old type pick up kasi yung samin