Backfire Screen
#11
01-26-2007, 02:58 PM
RE: Backfire Screen
I have been wafflinga bit on whether to do the backfire screen removal. I struggled for a long time to get my jetting right, and I think it is finally there, or at least close. That being the case, I am a little hesitant to add in more air without adding in more fuel as well.
Right now I have the 132 main, 40 pilot, 2.25 turns out and the N1TC needle on the 2nd clip. For those of you that pulled the screen, what did you do to add more fuel? Or did you just leave your carb setup unchanged?
I ditto the request for the Twin Air part number.
Thanks to all,
Chris
Right now I have the 132 main, 40 pilot, 2.25 turns out and the N1TC needle on the 2nd clip. For those of you that pulled the screen, what did you do to add more fuel? Or did you just leave your carb setup unchanged?
I ditto the request for the Twin Air part number.
Thanks to all,
Chris
#12
01-26-2007, 03:06 PM
RE: Backfire Screen
cwgoff,
Are you runnig with the air lid off? Also, is your midrange devoid of any surge or sputter? I'm asking because I feel that 130-132 main is pretty much spot-on for the CVK with air lid removed. I also noticed that A16tony was running with the highflow snorkle, 128 main, but had a midrange sputter. Since youare running an N1TC needle, I am asuming you are using a keihin main jet as well? I'm thinking theupper-midrange sputter that some people are having is because their main jet is too small.
As far as backfire screens go, I mentioned this earlier in a different thread, but I talked with my dealer about this a few months ago. He said that the Kawasaki pretty much broad sworded the liability issue by installing the backfire screens regardless of carb type, but said that fireballsare prevalent only when youhave pumper carb.
No way I would run my pumper without some kind of backfire protection, but I don't think I'd have an issue with the CVK. I'm just waiting for all of you guinea pigs to figure-out which filter is best.
Are you runnig with the air lid off? Also, is your midrange devoid of any surge or sputter? I'm asking because I feel that 130-132 main is pretty much spot-on for the CVK with air lid removed. I also noticed that A16tony was running with the highflow snorkle, 128 main, but had a midrange sputter. Since youare running an N1TC needle, I am asuming you are using a keihin main jet as well? I'm thinking theupper-midrange sputter that some people are having is because their main jet is too small.
As far as backfire screens go, I mentioned this earlier in a different thread, but I talked with my dealer about this a few months ago. He said that the Kawasaki pretty much broad sworded the liability issue by installing the backfire screens regardless of carb type, but said that fireballsare prevalent only when youhave pumper carb.
No way I would run my pumper without some kind of backfire protection, but I don't think I'd have an issue with the CVK. I'm just waiting for all of you guinea pigs to figure-out which filter is best.
ORIGINAL: cwgoff
I have been wafflinga bit on whether to do the backfire screen removal. I struggled for a long time to get my jetting right, and I think it is finally there, or at least close. That being the case, I am a little hesitant to add in more air without adding in more fuel as well.
Right now I have the 132 main, 40 pilot, 2.25 turns out and the N1TC needle on the 2nd clip. For those of you that pulled the screen, what did you do to add more fuel? Or did you just leave your carb setup unchanged?
I ditto the request for the Twin Air part number.
Thanks to all,
Chris
I have been wafflinga bit on whether to do the backfire screen removal. I struggled for a long time to get my jetting right, and I think it is finally there, or at least close. That being the case, I am a little hesitant to add in more air without adding in more fuel as well.
Right now I have the 132 main, 40 pilot, 2.25 turns out and the N1TC needle on the 2nd clip. For those of you that pulled the screen, what did you do to add more fuel? Or did you just leave your carb setup unchanged?
I ditto the request for the Twin Air part number.
Thanks to all,
Chris
#13
01-26-2007, 05:14 PM
Join Date: Dec 2006
Location: Harriet, Ar.
Posts: 73
RE: Backfire Screen
The K&N #1287 is what is listed on K&N's web site for the KLX250S. Someone mentioned that the Twin Air Filter had to be put on at a angle. Will it fit under the lid? I will be running with the High Flo Snorkel. I might have messed up here. I ordered a 128 main jet/40 Pilot/N1TC needle/and Muzzy exhaust system. You say I need a larger main jet! Don't want to have to remove the carb twice. Maybe won't have to. Might not get it back on the first time
#14
01-26-2007, 05:29 PM
RE: Backfire Screen
ORIGINAL: tremor38
cwgoff,
Are you runnig with the air lid off? Also, is your midrange devoid of any surge or sputter? I'm asking because I feel that 130-132 main is pretty much spot-on for the CVK with air lid removed. I also noticed that A16tony was running with the highflow snorkle, 128 main, but had a midrange sputter. Since youare running an N1TC needle, I am asuming you are using a keihin main jet as well? I'm thinking theupper-midrange sputter that some people are having is because their main jet is too small.
cwgoff,
Are you runnig with the air lid off? Also, is your midrange devoid of any surge or sputter? I'm asking because I feel that 130-132 main is pretty much spot-on for the CVK with air lid removed. I also noticed that A16tony was running with the highflow snorkle, 128 main, but had a midrange sputter. Since youare running an N1TC needle, I am asuming you are using a keihin main jet as well? I'm thinking theupper-midrange sputter that some people are having is because their main jet is too small.
After reading your post, I guess I probably ought to look at getting some more air in there with my current setup to see what happens. It's easy enough to just pull the duct-tape off of the hole as step #1, or I might just pull the whole lid for a dramatic change to see if I can tell a difference.
If that helps things out, then I am still left with the question of the backfire screen though. If I get things where I want them and then pull the screen, do you think I will then need to begin working on my jetting again to get some more juice to offset the extra air?
I want more power and all, but I am danged tired of pulling that carb. I have been into it 3 times so far.
Thanks for the info.
#15
01-26-2007, 11:14 PM
RE: Backfire Screen
Twin Air :: Backfire Filter :: All Yamaha YZ 4-Strokes
Twin Air Part #: 152313
Here's a link (but the actual filter doesn't look like the picture): http://shop.twinairusa.com/catalog/p...65a70089cfc4be
Twin Air Part #: 152313
Here's a link (but the actual filter doesn't look like the picture): http://shop.twinairusa.com/catalog/p...65a70089cfc4be
#16
01-27-2007, 04:24 AM
RE: Backfire Screen
YYYguy,
Do you know for sure that is indeed a filter that will fit the KLX 250 airbox?
The reason I ask is my bike is in Thailand and I will be bringing the filter back over from the states. I just wanna make sure it fits as i won't have a second chance.
Anytime your engine can utilize additional fuel/air it will be a benefit up until the flow limits of the motor are reached. My backfire screen is going assuming this filter fits.
Thanks.
Do you know for sure that is indeed a filter that will fit the KLX 250 airbox?
The reason I ask is my bike is in Thailand and I will be bringing the filter back over from the states. I just wanna make sure it fits as i won't have a second chance.
Anytime your engine can utilize additional fuel/air it will be a benefit up until the flow limits of the motor are reached. My backfire screen is going assuming this filter fits.
Thanks.
#17
01-28-2007, 07:41 AM
RE: Backfire Screen
Yes, the TwinAir filter (Part No: 152313) fits the KLX250S airbox.There's aslight distortionof the foam element, but its nothing to worry about.
I'll be posting a new thread (with pics!) of the Twin Air filter and how to remove the backfire screen.
I'll be posting a new thread (with pics!) of the Twin Air filter and how to remove the backfire screen.
#18
01-28-2007, 02:49 PM
RE: Backfire Screen
ORIGINAL: cwgoff
Tremor38, it was that mid-range sputter/surge that I was chasing trying to prevent. I went all over the place with my jetting & with different airflow configs. I did run without the airbox lid for several weeks. I put it on just before the TdAII but I removed my cut-down stock snorkel from the double snorkel mod leaving a snorkel-size hole just in front of the fat snorkel. This is how it was when I arrived at TdAII.Someone suggested that I was lean, so I duct-taped the hole in front of the snorkel. At that point I had my N1TC on notch #4. Marty suggested that I was actually rick, so I moved the needle from #4 to #2. With that change I got a lot more power throughout the range, and the stutter is almost completely gone. I was hesitant to mess with it anymore after that because I wanted to enjoy the rest of the rally. Since then, I have just ridden the bike. No time for wrenchin'.
After reading your post, I guess I probably ought to look at getting some more air in there with my current setup to see what happens. It's easy enough to just pull the duct-tape off of the hole as step #1, or I might just pull the whole lid for a dramatic change to see if I can tell a difference.
If that helps things out, then I am still left with the question of the backfire screen though. If I get things where I want them and then pull the screen, do you think I will then need to begin working on my jetting again to get some more juice to offset the extra air?
I want more power and all, but I am danged tired of pulling that carb. I have been into it 3 times so far.
Thanks for the info.
Tremor38, it was that mid-range sputter/surge that I was chasing trying to prevent. I went all over the place with my jetting & with different airflow configs. I did run without the airbox lid for several weeks. I put it on just before the TdAII but I removed my cut-down stock snorkel from the double snorkel mod leaving a snorkel-size hole just in front of the fat snorkel. This is how it was when I arrived at TdAII.Someone suggested that I was lean, so I duct-taped the hole in front of the snorkel. At that point I had my N1TC on notch #4. Marty suggested that I was actually rick, so I moved the needle from #4 to #2. With that change I got a lot more power throughout the range, and the stutter is almost completely gone. I was hesitant to mess with it anymore after that because I wanted to enjoy the rest of the rally. Since then, I have just ridden the bike. No time for wrenchin'.
After reading your post, I guess I probably ought to look at getting some more air in there with my current setup to see what happens. It's easy enough to just pull the duct-tape off of the hole as step #1, or I might just pull the whole lid for a dramatic change to see if I can tell a difference.
If that helps things out, then I am still left with the question of the backfire screen though. If I get things where I want them and then pull the screen, do you think I will then need to begin working on my jetting again to get some more juice to offset the extra air?
I want more power and all, but I am danged tired of pulling that carb. I have been into it 3 times so far.
Thanks for the info.
It's not possible to change the main jet on a pumper while it's onour bikes, but I've heard you can loosen the hose clamps, remove the throttle cable and rotate the CVK body enough tochange the main jet. I dunno if having the KLX300 tank on your bike will affect that?? I doubt it.
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