cleaning a CARB (Plus setting up)

Hi all
ok i have so much on my plate so unforunatly never got to get into peds yet
BUT
gotta get my bros nrg going
i understand how a ped works (rebuilt a typh 125 from scratch back in the day)
but it was standard never tuned
i get how variators and rolles kinda work (bit like gears on a mountain bike i guess)

anyway when taking apart a caerb to clean this is what i do is it correct?

Take carb off bike
take off choke and all rubber parts gaskets etc

hold in air and spray carb cleaner all through carb holes etc

if float bowl is plastic i just clean with a lil wd40 (as worried carb cleaner will damage it)
ive heard people soaking carbs in lemon juice??

anyway with float bowl gaskets is their anyway of treating them to make them last longer?
ive heard smear with synthetic grease?

Now this is the part of carbs i find hard
if you tune
say you got a 50 cc then you put a 70cc kit on
then you need to upjet
But what about air screw?? (not idle screw i get that)

so in my mind when you tune
first you must get airscrew correct then get jetting correct
help from carb pros on here would be great

PS HOW MANY TIMES SHOULD I BACKOUT AIRSCREW ON NRG FITTED WITH 70CC KIT
STANDARD 17.5 CARB

 

WOW NOONE ON HERE GUNNA HELP?

 

Hey

To clear my carb I usually just blast it with my air compressor, that works a treat. As long as it isnt on from WW1 that should be fine. I ve soda blasted stripped carbs in the past as well when they were in etrrible state, did do the job.

Never been too bothered about the gasket tbh, they cost nothing to change and never had a problem with them.

Tuning the carb is explained on many sites. Here is how I do it (no matter what engine size or what you are doing, carb tuning is done the same way):

First get your main jet sorted. Start high, go down 5 by 5. Plug check and able to full throttle without any dodgy stuff happnening.
Then check mid throttle position. Adjust the needle if required.
Finally tune the air screw. Unscrew it 1/4 at a time until engine sound and throttle opening is perfect.

You do it in that order as first step affects the second, and then the 3rd... blah blah blah...

No one can give you an exact jet size, needle position and air screw position over the internet. If they say they can?.. BS

 

so this is how everyone does it then?
ok i kinda get it
ummmm how much is a air compressor (although i live in a flat remember lol)

can you help though with my new carb help post please ma8

 

I got my one at auction, from a garage that was being closed so the price prob isnt the best indication you can get them for quite cheap and it is always handy to have. Not sure though if you don't have a garage how to store it (mine one is huge but you get small one).

For the carb, to be honest I just can't do it over the internet. just need to follow the above guideline (Or a morein depth guide.. Im sure there is one headlining a thread somewhere here).

I could tell you stuff, but it would just be silly and just wouldn't really help to be fair.

 

yeah i get you
thanks all the same
ummmmm im not totally stupied lol
i mean i completely stripped a yphoon 125cc srayed the frame, took engine to bits and rebuilt etc
but this didnt involve any tuning (so im not up their with you guys to be honest)
so i should just scrub outside of carb
blow through passages (and spray carb cleaner if any bad as i dnt have a compressor
then fit but whats the starting point for the airmix screw is it screw in all the way then back out 2&1/2
then 1/4 left to right to see whats better
if noone knows the start point for the nrg i guess ill just do what you told me as you seem to know alot
doing what you told me have you ever had a bike seize on you
cause if you havnt then i guess its safe to do what youve said
so thanks

 

p.s
i heard its great to soak really bad carbs in lemon juice?

 

ps so airscrew should be done first and then last as changing jet and needle clip etc effects airmix also?
or just plane do airscrew last?

 

never tried lemon juice ... a bit of pressure is generally needed to clear the tiny inner tubes...

Air screw should be done last, no first. The main jet affects the overall mixture, the needle only affect the mid throttle response and mixture flow.

 

got ya (yeah lemon juice as the acid in it eats at the dirt) also heard if your jets are blocked to boil them in water)
thanks for the help ma8
will do this tomorrow
so no matter what cc/head youve got or put on
no matter what air filter etc
you always do main jet first (then keep going down by 5 sizes do you mean) i thought it would be best to go down 2 sizes at a time?
then needle clip for midd throatle?
then airmix?

im trying to make sure i understand it correct
but surley even though i must do airscrew last their must be a initial setting like out 1 1/2 times or somthing ive heard?
not sure on this one?

but cheers ma8 your a helpful guy

 

I usually screw it completely and unscrew a full rotation.

 

ok cheers
i think ive got it now
what ever ped you get n tune etc
put airmix 1 turn out
then jet high
then go for a spin
and adjust to you like
then sort mid throttle by moving needle clip up or down
then sort airmix properly

then for rollers and clutch springs ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh
but this is more like gears on a mountain bike im guessing
i get kinda how it works
when spins centrigual fource makes the rollers roll out make it change gears at the front (like the 3 cogs on front mountain bike etc)
then the back at clutch hmmmmmmmmmm

anyway i got som much going on so once settled might try get into this ped stuff
for now just want to get this ped for bro correct (as he banged on a 70cc kit like a monkey knowing i had so much on my plate allready)

thanks though

 

it you dont have room for a compressor buy a can of compressed air from maplins

 

May be you can help as you seem to know loads of stuff...anyway came home from hols to find my zip in pieces including the carb anyway put it back together but having problems with air fule mixture my zip only does 35 mph and its bogging how can i set it up ???