fuel tap on/off

WhitePhantom SG

hi guys, do u off ur fuel tap whenever u park ur bike?
anyone got experience carb overflow b4?

seems that when i off the tap, start that time must warm up longer to let the petrol in Rolling Eyes Shocked

acoolboy7 SG

Unless got people trying to be funny go turn ur throttle, the fuel won’t overflow. But i always close one. Warming up standard one what. I never feel the difference.

ah_tee SG

last time my aprilia muz off, coz will overflow, as petrol can be seen coming out of the overflow tube at the carb

now my Fz no need

and i dun get wad u mean by muz warm out longer,
coz still got petrol in ur carb
mah, if not petrol go in, ur bike would have died

WhitePhantom SG

u riding fz or fzr? issit the fz is a Vtwin 4 stroke naked bike??
i saw one malay guy riding it from my work place there, dun know the model until someone told me...
old bike rite?
Rolling Eyes

ah_tee SG

sorry, me riding FZR, jus now neber say properly
FZR is a fairing bike,
FZ is a naked bike

yesh, my bike is 4 stroke v-twin
yesh, its old,err.. FK consider old?

my workplace there got an old old katana, but still in gd shape Laughing Surprised

ShunLi SG

a black katana 750? FH plate?

RAIDER SG

Ok lah, at least newer than tzr...

jungleboy111 SG

I always turn off my fuel knob whenever I park my bike. You never know what will happen to it when you are away.... Someone might knock over your bike, then....you can kiss your fuel goodbye....and also, if there's a leak and you leave it unattended, also goodbye.

Very Happy

WhitePhantom SG

i have tried leaving it on for a certain period n also leaving it off.
wat i get is: i got more mileage if i turn it off while parking, n vice versa.
i not sure whether petrol leaking or got 'evaporated'

ah_tee SG

its black, but i think its FC, always at one coffeeshop near diamond industries at macpherson area

ah_tee SG

not realli la, TZR also got FJ mah

RAIDER SG

Isn't fk newer than fj???

l3stat SG

eh i did discuss this issue with my friend before, but wanna hear you guys' views... cos we have no conclusion still.. hahhaa...

the fuel tank is connected to the carburettor flat bowl via the fuel inlet tube. the fuel petcock is located on this tube, so you can set on or off. when the fuel in the flat bowl fills to a specific height (preset by your float height), it pushes up on the floats, which activates the float valve to close off the fuel inlet. so no more fuel comes in from the fuel tank, and the level of fuel in the flat bowl is constant.

when your engine is DEAD/NOT ON/NOT WORKING, there is no pressure difference in the venturi... unless the itchy hand prick playing your bike's throttle go kick in gear and push start i dunno lar.... but the thing is, when your engine is not moving, there is no pressure difference in the carburettor venturi. twisting your throttle has two mechanical functions in the carb: pulling up the jet needle, and throttle slide. even as the main jet is fully open, when there is no pressure difference (cos engine IS NOT RUNNING), how would your cylinders flood? petrol evaporates yes, but to the extent of flooding the cylinders???

so i got a few questions i discussed with my friend:

if the engine is not running, i.e. no pressure diff in the venturi, twisting the throttle only opens the main jet and throttle slide, yes the venturi passage is opened, but there is no airflow, how is that petrol will defy gravity and come up through the main jet from the flat bowl(s)? yes evaporation occurs, but i believe not to the extent of flooding your cylinders. at most, the venturi and the cylinder will be saturated with petrol vapour, but that won't cause flooding right?

secondly, the flat bowl will never overflow, assuming that your floats and float valve are working and properly set...

eh if there's anything i've missed or got wrong, feel free to tell me ya???! really quite interested to hear views on this... Smile

l3stat SG

oh yes, and how do you guys cure the “tiong you” situation, or engine flooding situation?

l3stat SG

faulty float valves/incorrect float height on your aprilia?

nismoS132 SG

hmmmm, we all seem to think that the flooding occurs when the bike is in a state of rest, but then, i just got the thought that maybe, it occurs when you're starting the bike.

your float bowls are filled to the brim with petrol, and when you start your bike, the piston moves causing more petrol to be sucked in thus slightly flooding the carbs, there isn't enough air to sustain the ignition, the engine stalls, and there is excess petrol in the carbs.

rinse and repeat, and you get a flooded carb.

of course, this is just a theory and i could be wrong Smile

HighwayAngel SG

Yeah.... no need to warm up longer .... just pull ure choke and ride out of ure carpark and u can close the choke back....

HighwayAngel SG

erm ok,... i sort of get what ure asking... first i say about closing the fuel tap... its a good practice... closing it after u park ure bike, Y , cos just in case u got a wear out overflow pin. and what effect will this cause>>> fuels over flow from carby. Ok now for the cylinder block flooding thingy... this one will have to depends on individual rider..>>> for eg. some riders may not know how to control the throttle or amount of fuels going into the engine when startin... they may have open slightly abit more which the heat from the sparks is not sufficient to ignite the fuels and this would starts floodin...>>>eg. 2 some rider likes to go fast and stop... if u all can see from ure carby outlet to ure engine side... there is a lilttle tube which leads to a reservoir which is usually located either on top or at the top side over ure engine... this reservoir is actually to stored ure excess fuels so as to compensate the event where by u can slow down and speed up fast without encountering any hip cups. Those riders who have this habit... often have excess fuels in that reservoir and this may leads to floodin too... eg.3 there are oso some riders who like to off the engine and open the throttle at the same time.... this is a big NO NO. Cos y,... its becos when ure doing this... often u will have a lots of unburn fuels left in ure cylinder block. This will confirm cos floodin especially if the weather is cold. Now pls note that a normal ignition coils only produce about 20k volt to 25k volt to burn fuels and these values will only be reach when the engine is running when ure startin the engine... there wont be 20kv so its best not to open throttle and start unless ure sure that its wise to do that. If there are any opinion i would like to hear too. Hope what i said can help u guys

ah_tee SG

more of like worned pilot jet Razz

ah_tee SG

i heard the best way to solve tiam you is to if ur bike can start, start n close fuel, let the petrol in the carb flow finish

if cannot start, turn to reserve, full throttle all the way, then start

dun ask me the theory behind it, this is wad i see my friend do one

ar bo is to smoke, then when smoke finish throw the cig butt inside the fuel tank