Function of butterfly in carby cars?

[shqamar]

thanks usman bhai i will do that my question about spark plugs and your recommendation is still due i am still waiting for u to tell me the model number which suits my cultus and the gap i need to tell the guy to set it also i have bosch super 4 tip spark plugs u reckon it will do any good to my cultus should i use those in my car ?

[ZEESHAN84]

dear can any expert tell me about function of butterfly when car is on cng...
means is there any use of butterfly when car is on cng.????

[azharmangat]

Any good mechenic of butterfly in RWP/Islamabad for Cultus carby. Please give his telephone number. advance thanks.

[Xulfiqar]

the butterfly is actually called throttle valve - and controls how much of the air/fuel mixture load you want to ram into the manifold and hence cylinders - if it breaks off - you will have and uncontrolled engine that will never start or even run. It wont be broken off for sure unless you exploded dynamite in your manifold

What happens is that because our cheetah mechanics consistently fiddle with the throttle stop screw and want to adjust idle at 150 or 200 rpm - they screw it out making the throttle plate slightly touch the throat bore. Heat contracts the carburettor throat bore and the throttle sticks wearing it out and also damaging the bushing on which the throttle plate shaft rides on.

You are not supposed to set idle less than specified in the manual, one for smooth idle and two for long life of the throttle valve(s) aka butterfly.

If it is damaged the manual says to replace it - but its reconditioned the world over - get it reconditioned with proper angles on it, and set it once correctly - do not fiddle with it on a weekly bases. When setting on CNG - have a new filter in place and the ignition system should be A-OK - that way when you feel performance degradation you know its high time to clean/change the air filter.

[smijaz]

the butterfly is actually called throttle valve - and controls how much of the air/fuel mixture load you want to ram into the manifold and hence cylinders - if it breaks off - you will have and uncontrolled engine that will never start or even run. It wont be broken off for sure unless you exploded dynamite in your manifold

What happens is that because our cheetah mechanics consistently fiddle with the throttle stop screw and want to adjust idle at 150 or 200 rpm - they screw it out making the throttle plate slightly touch the throat bore. Heat contracts the carburettor throat bore and the throttle sticks wearing it out and also damaging the bushing on which the throttle plate shaft rides on.

You are not supposed to set idle less than specified in the manual, one for smooth idle and two for long life of the throttle valve(s) aka butterfly.

If it is damaged the manual says to replace it - but its reconditioned the world over - get it reconditioned with proper angles on it, and set it once correctly - do not fiddle with it on a weekly bases. When setting on CNG - have a new filter in place and the ignition system should be A-OK - that way when you feel performance degradation you know its high time to clean/change the air filter.

Understood everything but not the part in BOLD. If you dont mind can u plzz explain it.

[Xulfiqar]

The throttle plate(s) are tapered on their sides and are also not entirely flat when closed, the throttle stop screw keeps it open. What Im writing about is - if you unscrew the throttle stop screw the valve will go downwards sealing the bore further with the throttle blade, also to notice is the inlet manifold which is heated by the coolant, ergo it will heat the carburettor too, the first bit would be the throttle valves - the throttle valve bore will contract on heating up - as you are consistently working the pedal up and down while driving it will wear it oval and damage the bushing too as it has to flex to get it open again. (in an EFI car this can be more understood - there is a throttle stop screw that is not to be tampered with - if it is unscrewed the throttle plate jams shut - you can open it with your foots strength but it will wear it out quickly)

This is also a reason why A/T carby cars throttle valves (butterfly) do not wear out as quickly - the driver does not let go of the pedal to change gear. In M/T you have a dashpot for this purpose too to make the throttle close slowly, but it is required that your throttle plate is not going into the "jamming" region

[xebification]

Bro hope ya dun mind me askin about butterfly ?wahts dat ?

[Xulfiqar]

Bro hope ya dun mind me askin about butterfly ?wahts dat ?

throttle valves in the carburettor

[gmtabassum]

Dear mr usman ansari. I am new to this forum and do not know how to post the problem. I think you can judge the problem of my car. I have cultus 2003 non efi with both CNG & Petrol. I am having problem with vibration in body even the car is hot or cold. I have chenged the 03 engin foundations (thia), inspected the silencer completed. every thing is OK. but still vibration in the body while the car is at rest in start position. One mechanic said that there might be tapit or valve jaming problem in the head. Another problem when the car is on petrol then if i push the accelaratore hard it gives a slight jerk/missing if i give slight push then it is ok. please advise me.