Carby Tuning Problems!

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Nah cbf at the moment its too cold outside! im guna waist for someone who knows to giv us a tip! Quickprox that is sweet as! us gotta let us know how it runs now, and if worse comes to worst ill jus head down there and c if they can help me out. I just wanna c if i can do it myself first tho:D
 
If your bike is running well at Idle to approx one quarter throttle then adjusting the piolet screw wont acheive anything (divy already told you this) and doing it with a cold engine is useless.

If your problems are at full throttle then its most likely a main jet issue (a bigger main jet richens the mixture).

You say that your spark plug is black is this after killing your engine at full throttle (after about 10 seconds of flat chat) or after just slowing down and turning your engine off as per normal?

I suspect you have just turned your bike off and checked the plug (this wont help your full throttle issue)

What you need to do is dont touch anything on your carby and do the following

1. put a spark plug spanner in your pocket
2. warm the bike up to FULL TEMPRATURE
3. Find a long (preferably up hill) straignt
4. get up to full throttle and hold it flat for 10 seconds
5. Hit the kill swich and realease the throttle at the exact same time
6. hit the breaks
7. pull out your spark plug
8. post up what color your plug is after this test and we will tell you wat to do.
 
Divy said:
when its not running right from 3/4 to wot that means you dont have the right main jet, you have a 100 main jet on it now an its still rich so i belive you need to go for a bigger main jet, the bigger main jet will lean it out a bit more an should get it riding better on wot
im not sure what size you should get but i would get a 102.5 an a 105 main jet an try them both
Click to expand...

SOME of that advice is not quite correct!!
 
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Its half right (not the bit about increasing the jet size to lean it out though the fact that its most likley a main jet problem IS right)
 
cass38a said:
If your bike is running well at Idle to approx one quarter throttle then adjusting the piolet screw wont acheive anything (divy already told you this) and doing it with a cold engine is useless.

If your problems are at full throttle then its most likely a main jet issue (a bigger main jet richens the mixture).

You say that your spark plug is black is this after killing your engine at full throttle (after about 10 seconds of flat chat) or after just slowing down and turning your engine off as per normal?

I suspect you have just turned your bike off and checked the plug (this wont help your full throttle issue)

What you need to do is dont touch anything on your carby and do the following

1. put a spark plug spanner in your pocket
2. warm the bike up to FULL TEMPRATURE
3. Find a long (preferably up hill) straignt
4. get up to full throttle and hold it flat for 10 seconds
5. Hit the kill swich and realease the throttle at the exact same time
6. hit the breaks
7. pull out your spark plug
8. post up what color your plug is after this test and we will tell you wat to do.
Click to expand...



Hey mate thanks alot for the instructions! I just did that and came back to the comp and i saw u posted up the method! lol neway im tryin to get pics of it up now. And im just curious, what exactly is the mixture screw on the bottom of the carb for, and what will it do?
 
It adjusts the mixture in your pilot circut which is basicly the mixture at idle and up to about one quarter throttle.
 
yeah why do you say all my advice is wrong pitmaster all was right except i f@#ked up saying that bigger jet will make it leaner i know it will make it richer i just wasnt thinking straight an typed the wrong thing

at least i wasnt like the other people telling him to screw in his air/fuel screw

id say that was bad advice
 
Divy, i apologise it was worded too abruptly,

the fact you said, he knows its rich now but you told him to go even bigger on the main jet,

thats what i was trying to point out, and admit i was rude, sorry
 
the pilot screw does nothing to the main jet

the pilot screw affects the first 1/8th of the throttle

if the idle and bottom end performance is ok then all good

if the top end is crap and the plug is black the only choice is to change the main jet to a smaller size

the mixture screw is adjusted for the maximum idle speed
 
Hard to tell from those pics, the first one looks rich and the second one looks lean. I am assuming they were taken at the same time just different angles. Not to mention the focus was a bit out.
I think you have gotten yourself into trouble by having the jet drilled out rather than buying one. Go and get yourself a 100 or 102.5, cost you like $10.
Start from there and see how you go. As was said by some other boys, don't touch your pilot screw if you believe it is a main jet problem.
 
pitmaster said:
Divy, i apologise it was worded too abruptly,

the fact you said, he knows its rich now but you told him to go even bigger on the main jet,

thats what i was trying to point out, and admit i was rude, sorry
Click to expand...

nah thats sweet;) i f@#ked up on that post anyways lol
 
Sorry I didnt post straight back I had to go out for a while. I recon exactly what pegleg already said, and you should get a new jet.

I am assuming that you had no dramas with the original jet but you knew (from testing the plug) that it was lean at full throttle so drilled it out. I personally dont undersatand why guys keep drilling these jets out when genuine ones can be purchasesd for $10. Buy yourself a new main jet and see if the problem persists (you could buy a couple of different sizes if your keen and test ride each one).

The lesson to be learnt from this is if he had purchased a jet instead of drilling one he could change it back to the original and see if the problem goes away. Now he is stuck and we all assume that its the main jet but cant be sure and the original might have been the best one for his bike.
 
ill go back to my original question, Why did you get it drilled out? was the bike playing up than?

because it doesnt look like you needed to go bigger anyways, thats why its now playing up,
 
pitmaster said:
ill go back to my original question, Why did you get it drilled out? was the bike playing up than?

because it doesnt look like you needed to go bigger anyways, thats why its now playing up,
Click to expand...

I had my jet drilled bcos the last time i rode it i had just put a new pod filter on and it was running lean, so went for a bigger jet.
when i put it back 2gether i didnt even think of cleaning my filter(cos i just wanted to try it) lol neways its all sorted, ended up being that the filter was dirty and not letting enought air in to lean out the mix.
neways i guess i learnt my lesson now to clean my filter regularly.
Thanks for all ur suggestions it was good help and good to know so many peolple are willing to give advice!
 
avenger_125 said:
I had my jet drilled bcos the last time i rode it i had just put a new pod filter on and it was running lean, so went for a bigger jet.
when i put it back 2gether i didnt even think of cleaning my filter(cos i just wanted to try it) lol neways its all sorted, ended up being that the filter was dirty and not letting enought air in to lean out the mix.
neways i guess i learnt my lesson now to clean my filter regularly.
Thanks for all ur suggestions it was good help and good to know so many peolple are willing to give advice!
Click to expand...

LOL - I pointed out in a post that keeping air filters clean all the time is the BIGGEST performance secret known to man !!!!!!

1) To set the idle mixture . You turn the idle up - then turn the mixture screw in until the engine revs drop - then (counting the number of turns) turn it out until the revs drop - then turn it back in half way . Lower the idle speed and repeat the procedure until you get the engine plonking nice and smoothly just short of stalling - then you can turn the idle screw back up to get the best idle speed to suit how you ride . Then , if you want , you can screw the screw right back in - counting the number of turns , write it down somewhere for future reference , then screw it back out by the same number of turns . Once you know where the neutral mixture setting is between rich and lean , you can go either side to suit different temperatures etc .

2) Nobody mentioned that raising the "E" clip on the slide needle lowers it and leans out the main jet mixture and lowering the clip raises the needle and enrichens the mixture .

3) bogging is caused by not enough fuel - usually from too small a pilot jet OR snapping the throttle open quicker than the jets can respond (sudden vacuum drop) :)
 
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Cactus Jack said:
2) Nobody mentioned that raising the "E" clip on the slide needle lowers it and leans out the main jet mixture and lowering the clip raises the needle and enrichens the mixture .
Click to expand...

Mmm are you sure about this one?

Once the throttle is open past 3/4 the needle is pulled high enough out of the needle jet, than the size of the main jet begins to control fuel flow.

Adjusting the E clip wont affect the MAIN JET, and the Main Jet is the one metering fuel from 3/4 - Full throttle,
 
yeah i agree with pitmaster 3/4 to wot is main jet

if its rich between 1/4 an 1/2 then you adjust the e clip i belive!?
 
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