Jardine w/ k&n... stupid Q but please help a newbie

[rmkleman]

Ok, first of all i want to let everyone know this is a wonderfull site with a lot of smart dedicated people from what it seems to me. I looked over a lot of posts and i really dont think i could answer this unless i posed some specifics.

I just purchased a 03 400ex and it was all stock. I got myself a new jardine slip on exhaust and a k&n. First of all the jardine wakened the bottom end up for sure but when i put my k&n on it just made it seem like it was doggy and starving for fuel. I know am just about possitive i need to rejet but i would like some expert advice on what size to get? just the main jet? I have helped work on carbs before but i am not very confident of ripping my new ride apart and tinkering with vital parts... Need a little assurance from all of yall i guess :P

Also this thing is cold blooded! Its 80 degrees outside and i have to use the choke to get this thing running? Its kind of embarasing when there are people watching my try to start my new toy and it doesnt want to do. Do i need to go thru anything and clean it out? New plug or something help with this?

I am just starting out with this whole thing and its been a blast. I am sorry if these questions have been answered before and i am just repeating other peoples posts but please try to help me everyone i will do my best to help people as i gain more knowlege of my new bike. Thanks so much again!

Ryan

[redexrider]

I would suggest rejetting the entire carb, new pilot, main and needle. I went with the dynojet kit for the main and the needle, it comes with many main jets for different altitudes, and mods. It also comes with the Needle, and new clip, and full instructions on what jet you need to put in, what needle setting, and what air/fuel mixture screw setting. A very complete kit for someone who is not an expert (myself) I would also reccommend changing the pilot jet to a 40, that will take care of your cold start problems and idle problems. Any more mods and you might need to go to a 42 pilot. With my k&n, white bro's pipe, white bro's cdi, and open air box, at 100ft above sea level, california weather, I run a 170 (dyno) main, a 42 pilot, and 3rd notch on needle, 3 turns out on screw. My bike starts up right away with no choke and runs smooth. It made a world of difference for me.

[400exrider707]

Originally posted by redexrider
I would suggest rejetting the entire carb, new pilot, main and needle. I went with the dynojet kit for the main and the needle, it comes with many main jets for different altitudes, and mods. It also comes with the Needle, and new clip, and full instructions on what jet you need to put in, what needle setting, and what air/fuel mixture screw setting. A very complete kit for someone who is not an expert (myself) I would also reccommend changing the pilot jet to a 40, that will take care of your cold start problems and idle problems. Any more mods and you might need to go to a 42 pilot. With my k&n, white bro's pipe, white bro's cdi, and open air box, at 100ft above sea level, california weather, I run a 170 (dyno) main, a 42 pilot, and 3rd notch on needle, 3 turns out on screw. My bike starts up right away with no choke and runs smooth. It made a world of difference for me.


You are right to assume he needs to rejet however your own jetting seems off. Everything is good except for the 170 dynojet. That is rediculous huge for your mods.

redexrider. Your bike is really hard to start because it IS starving for fuel. This is why the choke is such a help in the starting process for you. I wouldn't even bother with the jet kits. The dyno kit is an ok kit to buy but really no need and a waste of money in my opinion. I would start with a 152 main, a 40 pilot, and move the clip on your needle down one position. Check out the tech articles at the top of the page for some assistance and pics of your jetting process, also and try a search, wealth of info for jetting a 400ex.:cool:

[redexrider]

Originally posted by 400exrider707
You are right to assume he needs to rejet however your own jetting seems off. Everything is good except for the 170 dynojet. That is rediculous huge for your mods.

redexrider. Your bike is really hard to start because it IS starving for fuel. This is why the choke is such a help in the starting process for you. I wouldn't even bother with the jet kits. The dyno kit is an ok kit to buy but really no need and a waste of money in my opinion. I would start with a 152 main, a 40 pilot, and move the clip on your needle down one position. Check out the tech articles at the top of the page for some assistance and pics of your jetting process, also and try a search, wealth of info for jetting a 400ex.:cool:

My bike is not hard to start, it starts up just fine. If you read the directions that come with the dynojet kit it tells you that for my elevation and mods, the 170 is where I should be. Remember that dynojet's jets are not the same in sizing as Kehin's a 152 Kehin might be ok, but not a dynojet main. And if you meant all of the above for the original poster, he does need to re jet. If his bike is running weird after doing those mods, then something needs to be done and it is jetting. Like I said before my bike is running in top condition, plug looks better than ever, it has great response, and starts like a champ.... My jetting is right on.

[Chino886]

Are you running an outerwear on the K & N?

[redexrider]

It isn't a K&N outerwear, I bought these nylon stretch over pre filters. You oil them up just like a filter, and clean them the same too. since I bought them, I have only had to clean my filter once every 5 rides, it shows no signs of any dirt but I figure after 5 rides it has to have something in it. These pre filter catch everything. And being thay they are just nylon cloth they are easy to clean and oil. I do plan on buying the outerwears though just to see the difference. I run an open lid aluminum air box, so I deffinately have to have something on it.

[Chino886]

Originally posted by redexrider
It isn't a K&N outerwear, I bought these nylon stretch over pre filters. You oil them up just like a filter, and clean them the same too. since I bought them, I have only had to clean my filter once every 5 rides, it shows no signs of any dirt but I figure after 5 rides it has to have something in it. These pre filter catch everything. And being thay they are just nylon cloth they are easy to clean and oil. I do plan on buying the outerwears though just to see the difference. I run an open lid aluminum air box, so I deffinately have to have something on it.

I would guess that is your problem, take it off and see if it helps......

I clean my filter after every ride, not worth the risk.

My suggestion would be to clean/oil filter, do you use the outerwear. If your filter is clean and oiled, it will do its job!

[krt400ex]

go with a 152 or 155 Keihin main and a 40 or 42 pilot.

[redexrider]

I don't have any problems with my bike CHINO, my bike runs fine... with the prefilter on, I am guessing you meant the question to the original poster????

[Chino886]

Originally posted by redexrider
I don't have any problems with my bike CHINO, my bike runs fine... with the prefilter on, I am guessing you meant the question to the original poster????

Yeah, sorry about that......;)