power filter, pre-mixing and jetting.
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what i learnt today, i try make it short and simple
the reason you feel a loss in power when you switch to a power filter (KNN etc), or if you remove your airbox. is because at ¼ and ½ throttle, there is too much air, and too little petrol in your carburator.
this causes your engine to run lean (which means, not enough petrol to burn)
your petrol is shot into your carburator through a needle and a main jet. the size of your main jet determines how much fuel is burned.
2T does not enter the carbs through the main jet.
when you switch to using pre-mix, you are increasing the thickness of your petrol, because now, there are 2 things flowing through the main jet, petrol and 2t.
assuming your mixture is 30:1, you are actually pumping 3.33333333333% less petrol into your carburators (which if you had paid attention earlier, causes your engine to run lean).
so if you do not have an air box, if you removed your 2t pump. and you are still using your original main jet, you are actually burning less petrol than is needed for your bike.
this is why you lose pick up.
basically, the same theory applies whenever you modify the airflow of your bike.
if you kuitoh your pipe, that means your exhuast is going to flow better, which also means there is going to be more air in your carburator.
if you change your entire pipe, there is going to be EVEN more air in your carburator.
a simple solution is to just reduce the airflow into your carburator, but this will reduce your top end power, because at full throttle, the engine will be running to rich (means too much petrol and/or carburator tio flood)
however, this is all mototiams do
the real solution is to buy a bigger main jet as well as longer needle.
happy modding.
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by the power of greystone
i
am
HE-MAN! -
a
[This message has been edited by nismoS132 (edited 15 March 2002).] -
b
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press for NOS
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No wonder my Piston will jammed that time along Lim Chu Kang Road at 160km/hr
Cos I open full-throttle....
Nw my 2T pump open a bit bigger liao,
( dunNoe hw my Mechanics do it ), there's more smoke then before when I move off but pick-up (acceleration), drop and is not as responsive as before.... .
Thanks for ur info Henry, any advice that I can hav betta pick up for my bike?
Other than changing the size of spocket? -
change ur gear ratios with a better CDI
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tOngEh
A good rider is one who can live long enough to ride another day. -
aiya henry what you say is just normal
but tuning might seems easy to all of you but it is actually very difficult to tune so dun ever try it yourself at home ... it will only make your bike worst ...
when ever you change a part example air filter ... you need to retune your bike ... same goes to exhuast ...
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wish u good luck
wish u bad luck
wish u born a baby duck -
nick ah
tune is tune.
but it is not enuff.
tuning is just moving the power from 1 end to the other end.
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press for NOS
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when tuning your mech will check for you your jetting also mah ...
actually this post is just for testing purpose hahaha
new signature
------------------Originally posted by nismoS132:nick ah
tune is tune.
but it is not enuff.
tuning is just moving the power from 1 end to the other end.
wish u good luck
wish u bad luck
wish u born a baby duck
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So wat will happen if a SP is without an air box, original pipe(mod to empty) and racing carb?Will it spoil easliy and is it recommanded?
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not spoil lah
must tune loh if not no max power
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feel like removing the filter frm my exhaust pipe... (tong exhaust)
issit good.. in terms of power.. -
If u guyz really wants to alwayz race, u guyz must let more 2T into the engine to lubricate yr piston to minimise the percentage of getting yr piston jam...
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[THIS IS A COMPUTER GENERATED MESSAGE THEREFORE NO SIGNATURE IS REQUIRED] -
im using knn filter and alreadi tong pipe liao.i also change my oil get bigger to 215 instead of the orginal 210. I feell that the bike respnd is veriveri slow and pick up also slow like shit.And when ever it reachs rpm5-6k, it like koncking sound from pistion....can u explain?
its a lean engine gd???
cheers thankssss