Black smoke from 4 stroke bike

[Chaoz]

Hi, my bike got black smoke coming out from exhaust pipe when i "zua" at lower gear..

 

I know it's normal cause it's clearing carbon right? But what worries me is why somehow there's always black smoke.. the carbon wun clear finish de meh?

 

normal riding and idling still ok.. no black smoke or anything.. is only when i drag my rpm up then will have..

[OhMiGosh]

Hi, my bike got black smoke coming out from exhaust pipe when i "zua" at lower gear..

 

I know it's normal cause it's clearing carbon right? But what worries me is why somehow there's always black smoke.. the carbon wun clear finish de meh?

 

normal riding and idling still ok.. no black smoke or anything.. is only when i drag my rpm up then will have..

 

tat one is carbon , u using stock pipe?>> if white smoke then problem

[Chaoz]

yeah stock pipe.. juz feel strange why the carbon like never ending de..

[akobana]

tat one is carbon , u using stock pipe?>> if white smoke then problem

 

White smoke got problem?! OMG. sometime there is white smoke coming out from my pipe while idling. got even carbon flew out when idling.

 

Anyway, got white smoke very serious?

[stsoh]

Hi, my bike got black smoke coming out from exhaust pipe when i "zua" at lower gear..

 

I know it's normal cause it's clearing carbon right? But what worries me is why somehow there's always black smoke.. the carbon wun clear finish de meh?

 

normal riding and idling still ok.. no black smoke or anything.. is only when i drag my rpm up then will have..

 

black smoke = poor compression.

it means worn piston rings n cylinder linear.

low rpm no black smoke coz compressions r not as high as when u ram your engine.

[Chaoz]

black smoke = poor compression.

it means worn piston rings n cylinder linear.

low rpm no black smoke coz compressions r not as high as when u ram your engine.

 

huh? then how? need to overhaul ah? will it help if i use better grade petrol? what is the best solution to it? in terms of price and durability..

[OhMiGosh]

White smoke got problem?! OMG. sometime there is white smoke coming out from my pipe while idling. got even carbon flew out when idling.

 

Anyway, got white smoke very serious?

dont get confused with water vapour.. normally have when the weather is cold or in the morning when you start your bike. after awhile of riding will be gone.

yeah stock pipe.. juz feel strange why the carbon like never ending de..

 

black smoke = poor compression.

it means worn piston rings n cylinder linear.

low rpm no black smoke coz compressions r not as high as when u ram your engine.

u sure? i thought its supposed to be white smoke? anyway if he claimed that during high rev nia.. i belive is the carbon . gotta differentiate smoke and carbon. if u get what i mean go take a look at those old cars and diesel vehicles.. those coming out from their exhuast is black smoke.. even at low rev also will come out one.

huh? then how? need to overhaul ah? will it help if i use better grade petrol? what is the best solution to it? in terms of price and durability..

seriously is ur stock exhuast pipe. if u do change to a after market one u can see the different. cause stock exhuast pipe inside got this "honeycomb" structure which traps alot of carbon. a v good example is the super4 stock pipe. go try high rev one old super4 with stock pipe and u'll know what i mean.

[Yatz86]

confirm carbon...anyway why is it never ending is u must understand the principle of how petrol burns. carbon is the result of petrol not burning it properly. U cant exactly remove the carbon completely in ure pipe by revving it. Revving it can only remove some of the carbon. Not hot enough to heat up the carbon inside.

 

we old bikes confirm got lots of carbon left by our previous owners. So the only way to get rid of it is to get a blowtorch & heat up ure pipe. another solution is get a new pipe + header.

[JbAtRaCeR]

Black smoke= OverRich Air/Fuel mixture due to either tuning too rich or air filter too dirty.

 

White smoke = Caused by cold weather(cold air with lots of moisture),but if hot weather somethings wrong(might be coolant burning leaking into combustion chamber)

 

Blueish white smoke = Oil control rings gone,causing engine oil to leak pass thru the rings and burn in the combustion chamber.

[Chaoz]

so solution is juz do tuning or change exhaust pipe right? good good..

[JbAtRaCeR]

so solution is juz do tuning or change exhaust pipe right? good good..

 

Tuning and air filter first...its cheaper than buying new exhaust pipe.

[diddy the patient]

so solution is juz do tuning or change exhaust pipe right? good good..

 

or can buy new bike

[Unagi]

Black smoke= OverRich Air/Fuel mixture due to either tuning too rich or air filter too dirty.

 

White smoke = Caused by cold weather(cold air with lots of moisture),but if hot weather somethings wrong(might be coolant burning leaking into combustion chamber)

 

Blueish white smoke = Oil control rings gone,causing engine oil to leak pass thru the rings and burn in the combustion chamber.

 

JbAtRaCeR is right.

 

black smoke = poor compression.

it means worn piston rings n cylinder linear.

low rpm no black smoke coz compressions r not as high as when u ram your engine.

 

(No offence intended but) Compression does not increase with the number of crank revolutions.

[Chaoz]

or can buy new bike

 

yeah agree.. any sponsorship?

 

but even if buy new bike, without proper tuning, this problem will arise sooner or later right?

[dinie]

dude take out your pipe, decarbonise it and then tune your carburetor. like what JbAtRaCeR said. your bike is most likely running too rich. and it has been running like that for a long time thus the carbon build-up. change to a new spark plug for good measure.

[LordCani]

Suggest u go for carb wash and tuning, as mentioned by them, i feel that ur air fuel mix not well tuned... Should not be a big problem la.

[Raptor]

Black smoke= OverRich Air/Fuel mixture due to either tuning too rich or air filter too dirty.

 

White smoke = Caused by cold weather(cold air with lots of moisture),but if hot weather somethings wrong(might be coolant burning leaking into combustion chamber)

 

Blueish white smoke = Oil control rings gone,causing engine oil to leak pass thru the rings and burn in the combustion chamber.

 

Fully agree with you.

 

With regards to the white smoke and blown head gaskets... either the engine oil will turn milky coloured due to contamination by the cooland and/or the coolant will turn oily and the radiator level keeps dropping due to coolant being pushed to overflow tank.

[JbAtRaCeR]

dude take out your pipe, decarbonise it and then tune your carburetor. like what JbAtRaCeR said. your bike is most likely running too rich. and it has been running like that for a long time thus the carbon build-up. change to a new spark plug for good measure.

 

Bro,just asking,how normally the mech decarbonise 4 stroke exhaust,is it the same as the 2 stroke ones(cut open stomach,burn with oxy flames). So far during my vespa days i use soduim hydroxide aka drain cleaners. Pour it inside the exhaust,add hot boiling water,slosh it around,wait for 10 mins,slosh again. Very2 "leceh".

[stsoh]

JbAtRaCeR is right.

 

 

 

(No offence intended but) Compression does not increase with the number of crank revolutions.

 

i shouldn't say compression.

 

u r rite compression doesn't change but pressures differs from low rpm to high rpm due to speed of compressions.

 

yes, richly tuned carb fuel/air mixture or choked air filter can cause black smoke, so does poor compression from old worn out engine.

[dinie]

Bro,just asking,how normally the mech decarbonise 4 stroke exhaust,is it the same as the 2 stroke ones(cut open stomach,burn with oxy flames). So far during my vespa days i use soduim hydroxide aka drain cleaners. Pour it inside the exhaust,add hot boiling water,slosh it around,wait for 10 mins,slosh again. Very2 "leceh".

if you ask me, i'd say decarbonizing an exhaust pipe is not really that a technically difficult job. so i go to JB and do it. the mech will take the whole pipe including headers out. if the pipe can be split to the different sections even better. then he will oxyflame out all the carbon bits. you'll see lotsa smoke and carbon coming out. he will keep doing it until he is satisfied that there is minimum carbon. i got charged like 70 bucks for a job like that in SG before as compared to only 50 ringgit in msia. but beware, if u have super chrome pipes, better tell the mech to be gentle. oil can polish away, but dents and scratches are much more troublesome..

[Ah Chi]

Bro you bikes sibey alot of problem haha.

 

I think you are talking about your RVF right? I think it needs a tune. 10km/h is maddness IMO. And I am thinking those black smokes are cause by rich mixture.

 

White smoke can be due to vapour cos dew can accumulate in your exhaust system. But warmed up bike mustn't give you white smoke UNLESS it's excessive 2T for 2strokies. Enjoy