Quick mixture question

[RS2MATRIX]

Cant seem to find a straight answer from my manual, so does anyone know in general, on the mixture screw on the carb, which way makes it leaner and which way makes it richer.

Reason i ask, ive just slotted on a new k&n style air filter, pretty pleased as it has given me an extra little boost, but now worried about running it too lean.

Is there an easy way i can tell?

Also, the sound is a little different, sounds the same idling but is way louder and sounds a bit like when you have an air leak, if you know what i mean?

Is the change in sound normal?

Cheers, Nick

[Vincent]

The standard airbox is a silencer aswell as a filter so the noise is normal. I'd jet up rather than mess with the air screw. Most aftermarket pipes require more fuel rather than less air

[NSR Mick]

The air screw only affects idle jetting.
____________________
If you dont like the way that I ride.......Stop trying to keep up!!!

[Timmeh]

[stirlinggaz]

hi,
what carb is it?
your carb will likely have 2 adjustment screws.
one in middle of carb body will be for adjusting idle speed only.
your other adjustment screw will be one of these :
AIR ADJUSTMENT SCREW - usualy located nearer airbox/filter.
adjustment - anti-clockwise to lean - clockwise to richen.
MIXTURE ADJUSTMENT SCREW - usually located closest engine/barrell. adjustment - anti-clockwise = rich, clockwise = lean.
so you have to find it first & identify what it does!
on my chinky 4 stroke 125 - adjustment screw is actually located on the bottom of the carb, facing downwards!
but applying the logic above, it was closer to engine, so to make it run a bit leaner, i turned it inwards (clockwise).
hope that helps.
plug chops are a must though.
cheers,
GAZ

[RS2MATRIX]

[stirlinggaz]

[Ant132]

Hi, ive just checked my plug after reading this and it is like a darkish brown colour, and the electrode part (i think its called the electrode) the middle part of the plug, has a white ring around it?

What does this tell me as im interested in what you said timmeh, i too am concerned with my fuel/air mix

Ant.
____________________
1980 Suzuki TS50 ~ 1984 Honda CB400N ~ 1992 Triumph Trident ~ 1998 Suzuki Bandit 1200

[Timmeh]

A picture paints a thousand words, so...

https://www.aa1car.com/library/reading_spark_plugs.jpg
____________________
GSXR400 x2 | '94 RVF400 | '93 TZR125 4DL (again)
20:22:30 BLUEX5: i would love to be forced to undergo a**l plugging with different sizes
20:48:18 Temeluchus: comp you hunk of smouldering homos3x you

[Ant132]

Thanks for that Timmeh, Ill try and get you a picture of mine if thats alright,

but to be honest, it looks pretty mich the same as 'normal' but with a white ring from the middle..

Like this,

https://i101.photobucket.com/albums/m62/ant-147/sparkplug.jpg

i read the white can be due to lean mixture, being too hot and insufficient cooling. Is there a way to identify which?

Am i at any danger continuing running it this way?

Ant [/img]
____________________
1980 Suzuki TS50 ~ 1984 Honda CB400N ~ 1992 Triumph Trident ~ 1998 Suzuki Bandit 1200

[Timmeh]

The white ring could just be a burn pattern or something, it's typically the cone that tells you what's going on.

How long is the plug lasting?
____________________
GSXR400 x2 | '94 RVF400 | '93 TZR125 4DL (again)
20:22:30 BLUEX5: i would love to be forced to undergo a**l plugging with different sizes
20:48:18 Temeluchus: comp you hunk of smouldering homos3x you

[Ant132]

[stirlinggaz]

hi,
never too early for a plug chop!
looking at your plug wont give a proper indication of how its running,
unless you do it under load,
ie WOT.
search "plug chop"
cheers,
GAZ

[Timmeh]

Like Gaz says, it's never too early.

Go for a spin on your bike, let it get warmed up.

Open the throttle up, get the rpm's nice and high for a couple of seconds then pull in the clutch and hit the stop button/kill the ignition.

Coast to a halt keeping the clutch pulled in.

Examine your plug, this will tell you if the main jet is too rich or too lean. Anywhere from light tanned to milk chocolate cone is good, along with nice black electrodes. Don't forget on a 2T you've also got oil in the mix, so it might be a bit darker. You might have to clean the plug a bit and try again if you can't tell what's what. You definately don't want to see a white cone - that's too lean. A black cone with sooty electrodes is too rich which is slightly less worrying but still needs to be looked at.

On most carbed bikes the standard jetting aims to be stoichmetric at idle and then getting ever-so-slightly richer through higher RPMs.

If you're still having trouble you could try a colortune, they work great on singles, 2Ts included.
____________________
GSXR400 x2 | '94 RVF400 | '93 TZR125 4DL (again)
20:22:30 BLUEX5: i would love to be forced to undergo a**l plugging with different sizes
20:48:18 Temeluchus: comp you hunk of smouldering homos3x you

[Ant132]

Thanks lads!

Will do that in the morning, is it ok to let the bike cool down before getting to the plug or does it have to be done stragiht away? Also can you just rev it in nuetral to fairly high rpm then kill it, would this work the same or is it better to take it on a run?

So if i discover im running too lean, upjet or adjust air screw? Or both?

Sorry for hijacking your thread rs2matrix

Ant
____________________
1980 Suzuki TS50 ~ 1984 Honda CB400N ~ 1992 Triumph Trident ~ 1998 Suzuki Bandit 1200

[stirlinggaz]

hi,
no, bike must be under load when doing the plug chop.
Timmeh's instructions are fairly spot on.
so you cant just rev the tits off it in neutral!
you dont have to take the plug out straight away,if your worried about it being hot - it will be so wear gloves.
or you could just leave it to cool down.
just dont try to re-start it or anything.
the ideas is to get an indication of how your plugs operating at wide open throttle,
what i do- go for a wee run, 10 miles or so,then head home,
500m from my house i get into 3 or 4th at high revs,(watching for police),
then when i get parrallel to my house i quickly pull in the clutch lever at same time as hitting the killswitch,
coasting to a stop at my gate.
get all my gear off, get the overalls on & remove plug.
think its actually better to leave it to cool down due to expanding metals & all that.
cheers,
GAZ