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The pointy end goes in the hole. If it is further down, it will plug the hole more. If it plugs the hole, less fuel will get it. Which is leaner. As above by some. Down is leaner, up is richer. Move it or them, one notch ad a time. How are you determining you need more or less fuel?

There are good tuning guides available. But nobody pays much attention. Start with the main jet, which involves the needle. Small adjustments can be made with the needle. Larger adjustments require changing the main jet.
Bigger number on the jet, more fuel. Smaller number, less fuel.

UK
 

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Whiterabbit, even your picture shows that by putting the clip in a higher position, the mixture becomes Leaner---take the advice and learn something:grin:

I know that myself and Krusty were racing and tuning bikes back when MOSES needed his Moped tuned:surprise:

Sam:nerd:
 

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Discussion Starter · #11 · (Edited)
The pointy end goes in the hole. If it is further down, it will plug the hole more. If it plugs the hole, less fuel will get it. Which is leaner. As above by some. Down is leaner, up is richer. Move it or them, one notch ad a time. How are you determining you need more or less fuel?

There are good tuning guides available. But nobody pays much attention. Start with the main jet, which involves the needle. Small adjustments can be made with the needle. Larger adjustments require changing the main jet.
Bigger number on the jet, more fuel. Smaller number, less fuel.

UK
Because I have a new Akrapovic exhaust and intake with the new mikuni carb. I was told to put a bigger main jet and figured with that I should go a notch UP then on the needle jet... this is why I made this post... even the picture starts with leaner at the top, hinting the higher up you go, the leaner=air and down for richer=gas... But you guys say that's backwards? So I need to go a notch UP for more gas...? I'm just confused at this point which again is why im asking. I'll take your advice for it, im sure you guys know. So, up for more gas and down lean.

Edit : rereading what I just wrote made me sound retarded. But bottom line, I need to go up a notch if I'm needing more gas up to 20% - 80% throttle and main jet im waiting for them to be delivered is 50-100% throttle.. which it's stock with a 98 main jet, I should try a 105 to start main jet for exhaust and air intake swap?
 

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Forget the air. Rich or leaner refers to the fuel. But the real test is on the road. WOT up a hill, to determine the main jet size. I could post a plug tuning guide, but as I said above, no one pays attention.

UK
 

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Discussion Starter · #13 ·
Forget the air. Rich or leaner refers to the fuel. But the real test is on the road. WOT up a hill, to determine the main jet size. I could post a plug tuning guide, but as I said above, no one pays attention.

UK
Post it, I will.. but, do you not see how the diagram I posted is easily confused? It starts with lean up top, pointing down to richer.. But what you said makes sense, go up to make a bigger space for fuel, not down to plug it like the diagram is stating down is richer=more fuel.
 

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Discussion Starter · #15 ·
Are you sure you even need to re-jet? Isn't this already a larger carb? What are the symptoms you are experiencing?
Slightly, its only a 2mm bigger carb than stock. But, with the air intake I installed (stock air box removed) and exhaust, I was told by a few others with basicslly the same setup and same bike, that a bigger main jet is a must. And it seems their correct because around 50mph which my stock top end was 60mph, it starts to lurch and not want to push too much past that 50mph so I ease off. It even feels like at that point I'm not getting enough fuel so I'm 99% sure this is the route I need to go... BUT, they all recommended a 115-125 main jet which seems alittle much to me with it being a stock 98 main jet, so I figured starting off with a 105 maybe 110 even would be a good start to see how that goes. And seeing if I'm doing that, I figured a notch on the needle jet would be proper.
 

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Raise-rich Lower[leaner :smile_big:

Sam:nerd:
The pointy end goes in the hole. If it is further down, it will plug the hole more. If it plugs the hole, less fuel will get it. Which is leaner. As above by some. Down is leaner, up is richer. Move it or them, one notch ad a time. How are you determining you need more or less fuel?

There are good tuning guides available. But nobody pays much attention. Start with the main jet, which involves the needle. Small adjustments can be made with the needle. Larger adjustments require changing the main jet.
Bigger number on the jet, more fuel. Smaller number, less fuel.

UK
Whiterabbit, even your picture shows that by putting the clip in a higher position, the mixture becomes Leaner---take the advice and learn something:grin:

I know that myself and Krusty were racing and tuning bikes back when MOSES needed his Moped tuned:surprise:

Sam:nerd:
Forget the air. Rich or leaner refers to the fuel. But the real test is on the road. WOT up a hill, to determine the main jet size. I could post a plug tuning guide, but as I said above, no one pays attention.

UK
... :plain: ...
 

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Dude, the needle fits inside the bottom of the slide and is held in place by a movable clip, a retainer and the slide spring. If the clip is put LOWER on the needle, it raises it's position within the slide and allows more fuel to flow(Raise the needle by lowering the clip position):smile_big:

I always went up one main jet size and lowered the clip one notch, to raise the needle. It always worked just fine.:grin:

Take a plug reading by finding an area where you can run full throttle for a quarter mile or so, pull in the clutch, hit the kill switch and pull off the road where it is safe to do so and remove the sparkplug. It should be a shade of very light brown but not:smile: a bleached white color. Google plug readings for pictures.:wink2:

Sam:nerd:
 
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