Greetings everyone! I have an '07 s40. I bought the screamin' eagle style muffler with a baffle off of ebay, I decided to weld it on to seal any leaks, and maintain a position away from the bike. I also modified the air filter, by cutting out the thick card board like element and replacing it with a breathe easy nu foam.I also removed the snorkle from the top of the air box and removed the side air box cover. of course I got this idea from another member, please forgive me, I dont recall his screen name.  Bottom line, the bike ran alot better, and sounded better. Now here is my problem:  I bought the dynojet stage one jet kit, and installed it as directed. The bike will idle fine, ride in all gears, but it is just kind of slugging along, and it doesn't accelerate very fast. I have changed the main jet from the 144, to the 142, and then the 140. It seemed to perform a little better with the 142, but not even close to the stock needle and jet. Hey I just want to get more out of my bike. Can some one with experience working with carbs and jet kits give me some advice?

I bought the dyno jet kit before I found your kit on ebay. the dynojet kit is for bikes with a stock air filter, but can be used on bikes with an aftermarket exhaust system. The needle comes with six grooves at the top. They instruct to place the holding clip on the fourth notch from the top and reuse the stock spacer,needle spring, and the small flat washer. They also instruct to use the 144 main jet. All of the jets that were sent as part of the kit have smaller holes than the stock main. I guess I will keep trying, but I may have to get your kit inorder to have any luck. Thanks for your response

$15 jet kit from lancer.
Apply elbow grease generously.
Read all the tech sect for carb tuning.
When stumped, ask.

The eduacation you'll get is priceless.

thanks yall i sent him a pm good news also seems he is in my state sc

Hello Gazoo! As you may have read, I dont have the stock air filter or muffler. The dyno kit is a stage one, and I changed the main jets around, but I could not get it to work right. I did not attempt to adjust the jet needle though. I got lancers jet kit yesterday and installed it today, and it runs like a scalded dog! I used the 155 jet, installed the new pilot jet, which the dyno does not have, and used the stock needle with two spacers supplied in place of the stock white spacer. These two spacers together are about half the thickness of the white spacer.

If you go to the tech/ref section, there is the table of contents/topic section. scroll close to the bottom of the carb mods portion and there is a heading "inexpensive high performance air filter". It was composed by old feller2. He tells all a bout it in a yoda/jedi like story. Feel free to ask me any questions about it, as I have followed his instructions, and I feel that it works great! The stock filter must Go! It has a super thick cardboard like element,and it cant breathe! So you can go to the cone or cut the element and replace it with a piece of new foam, that I found in walmart in the sewing/materials section.