Really Must Shake?

RAIDER SG

Been wondering abt this 4 a long time liao…My scram uses premix as it dosen’t have a 2t pump. Izzit really necessary to shake the bike for the petrol n 2t to mix? Although i’ve been doing this most of the time b4 mounting the bike, i do not find any difference when i ride it without shaking. Can anyone clear my doubts abt this hassle?

HighwayAngel SG

Nah u dun need to shake it unless u never used it more than a day

RAIDER SG

So does the 2 t really sink in the petrol?

NEW^_^BIRD SG

u buy petrol then mix wif 2t then put inside a plastic container tomoro u wake up n see u wil knw liao

No_regret SG

Better dont use plastic mineral bottle, coz it cant hold petrol long.

nick34 SG

might as well get a metal container

InSPirE78 SG

Mr. Green but i knw that if too much 2t to petrol will cause alot of white smk......white smoke=$70.00

l3stat SG

hmmm... actually if you think about it, petrol is made up of hydrocarbons, which are non-polar... so is 2T (derived from oil). when the 2 mix, they're miscible, meaning they form a solution that cannot be separated, which i think answers the question. but at the point you're premixing at the pump, shake it a little to get it to mix evenly before you ride off. to illustrate, stir a teaspoonful of sugar into a glass of water.. let it stand of a week and see whether you can see sugar crystals or not... Mr. Green

l3stat SG

have you done that yourself? or just hear-say?

NEW^_^BIRD SG

to lestat why dun we do tis test together and we let them knw the result. and u shld knw whether the 2t sink or not liao

nismoS132 SG

actually luke, 2t is subsceptible to settling after some time, depends on the kind of 2t though.

for example, look at bandung or milo etc etc, if you put it in a transparent cup, leave there for a day, you'll see the solution diluted at the top, and saturated at the bottom.

that's the same with 2t and petrol, just a solution. there's no chemical reaction to bond the atoms together, so they will seperate given enough time.

simple sec 3 n 4 chemistry Mr. Green

l3stat SG

well.. i really dunno man. seems like there's no incentive to do that... hahaha.. i don't premix.. best person to do that would be the originator of the topic i think... Mr. Green

l3stat SG

yes henry, but simple sec 3 and 4 chem cannot explain this properly. in the first place, you gotta know what a solution is.

bandung is a mixture. it is not a solution. the term has to be used correctly. i say bandung is a mixture because it's made of rose syrup and condensed milk. now, i'm not saying it's a mixture just because i know what it's made of, but rather because i know what constitutes rose syrup and condensed milk. condensed milk contains milk protein, which are insoluble in water, due to its large molecular mass, weakly polar nature. which is why you see a cloudy mixture when you mix it with water and leave it to settle. the particles are very fine, but they don't dissolve. proteins can be soluble, or insoluble, depending on their molecular size and polarity. milk protein happens to be one of those that don't.

so, bandung is a mixture, and it settles because the proteins are heavier and will settle.

now, petrol is made up of hydrocarbons. it is non-polar, which means there's no definite charge on any molecule, since the electron cloud shifts at random. it stays as a liquid due to weak intermolecular forces. i wish i could use the proper terms, but i'm rusty already. 2T, which is essentially also oil, but different in structure due to the use it's meant for, is also non-polar. mix 2T and water, see if it mixes or separates. oil and water don't mix because water is polar and oil is not. petrol and 2T are non-polar, and will dissolve to form a solution. a solution is also a mixture, but just that due to the intermolecular, OR ionic interactions, the 2 different particles cannot be separated. you can't separate the constituents of a solution by using simple mechanical methods. try to filter out sand from seawater using a funnel and filter paper, yes. try to filter out sugar from sugar solution (assuming it's not saturated and the sugar is fully dissolved), impossible.

one more point: 2T molecules are heavier in mass than petrol molecules generally. that's true. but will it settle? to answer that, read up on brownian motion. your tank of petrol does not just sit there, with the molecules waiting around for you to shake the tank so that they start moving. molecules don't stop moving. period.

l3stat SG

oh and the question still stands: have you done it yourself? cos i dunno what you're implying... be it that you're suggesting i do it so that i can see that you're right, or that you really want me to test it out, so that WE both can know?

l3stat SG

hey, bottom line, it's okay not to shake, but please do at the moment you're premixing before you ride off. relying on diffusion for the 2T and fuel to mix is not safe. too slow. shake when you add 2T, before you ride. but please get the mixture right yeah? as in if you're topping up fresh fuel into the premixed fuel. in case your piston jams (touchwood) because the mixing ratio is wrong, people will start saying what i've learnt in school that has been tested and proven by scientists is wrong.

nismoS132 SG

okok, bandung and milo is a bad analogy Smile

i have no idea how to explain it to you, but certain types of 2t (mainly the thicker ones that are purely for premix) do tend to settle given enough time to idle.

the question here is, how long? Smile