Big Gun and being too rich.....
#1
07-24-2006, 08:06 PM
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Big Gun and being too rich.....
I pulled my plug out to inspect it after an 80 mile ride on the pavement. The plug was black with soot. I think it's too rich, right? I'm not a tuner, I just follow directions. Does the bike need more air or what? Do I need to adjust my air/fuel screw? It's at 2.5 turns right now with a 128 main, 35 pilot, N1TC in 2nd position, drilled slide and snorkel removed from airbox lid. What could I do to lean it out a bit?
#2
07-24-2006, 10:38 PM
RE: Big Gun and being too rich.....
I wonder if the 128 puts too much gas in. My carb mod included a 125 main, and the plug is a nice tan. Has anyone experimented between the 125 and the 128? Can anyone comment on the difference?
[IMG]local://upfiles/2405/A8C56DD5F21E4C0AA987C22BE9749FCC.jpg[/IMG]
[IMG]local://upfiles/2405/A8C56DD5F21E4C0AA987C22BE9749FCC.jpg[/IMG]
#3
07-24-2006, 10:53 PM
RE: Big Gun and being too rich.....
I have a 128 main with a 40 pilot. I'm running the Big Gun and have an extra air opening on my air box. I'm seeing just a tad bit on the "chocolate" side of tan on my plug. It doesn't sound like there is any major difference between yours and mine except for the airbox opening. Mine is definately not rich..... I still have to choke mine in 90 degree weather to get it to start. Our elevations are similar, so I'm not sure what the difference is.
#4
07-24-2006, 10:56 PM
RE: Big Gun and being too rich.....
I forgot to mention that I'm not running the quiet core in the big gun. This could make a difference, without the quiet core it breathes a little better and therefore runs leaner.
#5
07-24-2006, 11:14 PM
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RE: Big Gun and being too rich.....
thanks for the replies guys. i don't really want to remove the quiet core because it's already extremely loud imo. i don't know really what to do. i mean it runs fine, pulls ALL the way to redline if requested. it does need choked to start in 90 degree weather as well. i have the 35 pilot, you have 40. would adjusting the air/fuel screw do anything? should i put in a 125 and a 40 pilot? would that take away from my midrange if i dropped down to a 125? what would moving up to a 40 pilot do? the carb is such a pain to get out and screw another jet in just to have it run like crap afterward. i tried to get a 40 when i rejetted the first time but no one had one around here. thanks again. Travis
#6
07-24-2006, 11:16 PM
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RE: Big Gun and being too rich.....
ORIGINAL: vfrpilot
I have a 128 main with a 40 pilot. I'm running the Big Gun and have an extra air opening on my air box. I'm seeing just a tad bit on the "chocolate" side of tan on my plug. It doesn't sound like there is any major difference between yours and mine except for the airbox opening. Mine is definately not rich..... I still have to choke mine in 90 degree weather to get it to start. Our elevations are similar, so I'm not sure what the difference is.
I have a 128 main with a 40 pilot. I'm running the Big Gun and have an extra air opening on my air box. I'm seeing just a tad bit on the "chocolate" side of tan on my plug. It doesn't sound like there is any major difference between yours and mine except for the airbox opening. Mine is definately not rich..... I still have to choke mine in 90 degree weather to get it to start. Our elevations are similar, so I'm not sure what the difference is.
#7
07-24-2006, 11:23 PM
RE: Big Gun and being too rich.....
I'm 2 1/2 out on the air screw. The 40 pilot gives you a little more gas on the low end and eliminates the popping on deceleration. You might want to try removing the quiet core just to get an idea of what it sounds like. Personally I don't think its that loud, but I'm sure that is a matter of prospective.
#8
07-24-2006, 11:25 PM
RE: Big Gun and being too rich.....
Forgot to mention your riding style. If you ride the bike hard (e.g. high rpm) a larger jet burns gas better. If you have a 128 main and don't run high rpms, maybe that's why your plug is dark. Just for fun, try running your 128 at a high rpm for a while, then inspect the plub. Next try putting around at low rpms and inspect the plug. This may give your an idea.
I had a KDX200 and used scream the bike, everything was fine. Then I started riding with my 6 year old son in the trails at a very slow pace. I started fouling plugs every ride. That was resolved by lowering the needle (less gas) in the combustion chamber (at low to mid rpms).
Needle affects gas flow low to mid rpm. Main jet affects gas flow at higher rpms to wide open....FYI
[IMG]local://upfiles/2405/2771F671FD054E348F9FE1A161367F63.jpg[/IMG]
I had a KDX200 and used scream the bike, everything was fine. Then I started riding with my 6 year old son in the trails at a very slow pace. I started fouling plugs every ride. That was resolved by lowering the needle (less gas) in the combustion chamber (at low to mid rpms).
Needle affects gas flow low to mid rpm. Main jet affects gas flow at higher rpms to wide open....FYI
[IMG]local://upfiles/2405/2771F671FD054E348F9FE1A161367F63.jpg[/IMG]
#9
07-24-2006, 11:53 PM
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Posts: n/a
RE: Big Gun and being too rich.....
i ran at around 6500-7000 rpms all weekend on the highway. i'm in the upper rpms more than not. i ride it pretty hard with wheelies and all. i like to hear it pull on accleration also so i let it rev alot. maybe running 87 octane has something to do with it. someone said on here running premium on our bike is a waste so i filled up twice with 87, but later when i was gapping my plug off the little sticker on the rear fender i noticed that minimum octane on our bike is 91. i'll fill it up with premium and then inspect it.
#10
07-25-2006, 12:48 AM
RE: Big Gun and being too rich.....
That sticker on the fender is mentioned in the manual, thats 91 Research Octane Number (RON) in the manual it states that 91 RON is equivalent to 87 octane pump gas which that octane level is calculated differently.
You can see my mods in my signature and I just pulled my plug yesterday and when it was all stock it was a very light tan, almost a shade above khaki. Now its a darker tan bordering on the chocolate tan. I've put on several hundred miles with the mods listed. I rode for about 10 miles without the airbox lid and holy crap was it ever a rip snorter off idle up to 7K, I'm talking break the tire loose with a crack of the throttle, literally from idle, and 1st or 2nd, and even third pulled hard. However with the lid off I think it was a hair on the lean side on top end as twice when I got up to 8K between gears there was a little louder pop in the exhaust and with the pop there was a drop in power. As soon as it popped I took another gear and didn't investigate further I just put the lid back on. Lid on vs off is a night and day difference with my bike.
You can see my mods in my signature and I just pulled my plug yesterday and when it was all stock it was a very light tan, almost a shade above khaki. Now its a darker tan bordering on the chocolate tan. I've put on several hundred miles with the mods listed. I rode for about 10 miles without the airbox lid and holy crap was it ever a rip snorter off idle up to 7K, I'm talking break the tire loose with a crack of the throttle, literally from idle, and 1st or 2nd, and even third pulled hard. However with the lid off I think it was a hair on the lean side on top end as twice when I got up to 8K between gears there was a little louder pop in the exhaust and with the pop there was a drop in power. As soon as it popped I took another gear and didn't investigate further I just put the lid back on. Lid on vs off is a night and day difference with my bike.