I would like to install one of these kits, but was wondering if there are any down-falls to it. Thanks!

 

The only down that I have heard of is that you might have to re-jet your carb. The rumor is that the increased airflow causes air/fuel mixture problems.

 

The K&N kit contains a K&N filter an assortment of jets and instructions. I got some main jets today for the Keihin carb they cost me $2.75 each. You can pick up the filter for about $35. If you need to adjust the needle jet you just shim it. This is a lot cheaper than a power kit.

 

Mudcat, I have a 02 500 Auto and I think it's running rich. What is your riding elevation and what jet size are you going to. My elevation is 1500 feet. Also, I am not convinced the K@N filter flows more air as the stick foam filter. What is you opinion on this.

 

As far as the K&N filter goes.. I have heard from other uesrs about issues with the filter allowing small particles to pass through it. They say that this could be damaging to the engine over time. This is what I have read in this and other forums anyway. A

Give jetting a try. I usually ride between 800 and 3000 feet, I moved my jet down to a 147 from the factory 150. My 375 seems to run more efficiently now.

Check your spark plug tip. If the plug is jet black all over like mine was, it's running rich. You can then incrementally decrease the size of your main jet to get you about where you need to be. Dont exepct any power gains with a jet change though, jetting on the 'Cats is more of a tweak than a performance mod.

Good Luck!

EtherNut

 

I purchased a 147.5 and a 145 main jets, I will do the adjusting when it warms up a little. Ethernut said about all there is to say about jetting. The Main jet only covers from 3/4 to full trottle, make sure your float height is at 17mm also.
As far as the K&N vs Foam filter debate, I have used both with a slight performance gain going to the K&N. There are a lot of both kinds out there and people use both with about the same results. I will be using a outer waers on my K&N. I have been using a Uni filter for some time now but they get torn with repeated washings and start to break down over time. That is why I got a new one, if the dealer would have had both in stock I think I would have still got the K&N. I do know that a K&N will not stop water entry as well as a Uni or other foam. I hope I don't have to find that out personally. I do believe if K&N filters didn't stop small particles there would not be as many sold as what there are. I use a K&N in my truck too with great results.
After I get my jetting done I will let you know of the changes and the results.

 

k&N jet kit has a diffrent shaped needle and the jet sizes are totaly diffrent.k&n jets run bigger,if you looked at a stock 150 main jet and then looked at a k&n 150 main jet, you could tell k&n jets run bigger in size! That and the needle and filter is what makes the diff.I can not see no down side to these kits.The good thing is that with theses kits it makes dialing your carb a snap!

 

The different companies have different #s on their jets. But a carb will not know the difference between a Dynojet jet or a Keihin jet. If you get the right size you have the right size no matter what # or name is on it. I believe with a jet kit for a Arctic Cat with a Keihin carb the needle jet is not included. I'm not positiv though. The same still applies the carb will not know the difference.

 

If the keihin main jet read 150 ,and then you grabed a k&n main jet that said 150.Your bike would NOT run the same with both jets!!!! K&N and Dyno jet run there own line of jets to go with there kits.THese jets are not exactly the same as a stock jet!! You are correct in that the atv will not notice regard less witch jet so long you have the correct size.