[09TRX450R]

I took in my 09 450 ER to the dealer because they said there was an update (recall) for the decompression shaft pin they did the work and when I went to pick it up the mechanic took me aside and said I noticed you have a K&N filter and they are great and a must for street stuff but not off road. I asked what do I get a uni because I figured he was going to say foam but no to my surprise he said the stock filter is way better than any filter on the market and doesn’t have to be cleaned as many times as a K&N. He then told me when he installs the HRC Power up kit he will do his best to rejet with that K&N but he would really recommend me taking it out and putting the stock back on because I will get a lot more out of the power up kit with it, the K&N will only hinder performance.
Does this make any sense?

 

[shadetree]

I took in my 09 450 ER to the dealer because they said there was an update (recall) for the decompression shaft pin they did the work and when I went to pick it up the mechanic took me aside and said I noticed you have a K&N filter and they are great and a must for street stuff but not off road. I asked what do I get a uni because I figured he was going to say foam but no to my surprise he said the stock filter is way better than any filter on the market and doesn’t have to be cleaned as many times as a K&N. He then told me when he installs the HRC Power up kit he will do his best to rejet with that K&N but he would really recommend me taking it out and putting the stock back on because I will get a lot more out of the power up kit with it, the K&N will only hinder performance.
Does this make any sense?

makes perfect sinse..he's trying to tell you..seeing how you have a kn filter in it..he's gonna have one hell of a time getting the jets to work in your carb because you got a kn filter in it !!..lol..if you had a stock filter in it..he won't be pulling his hair out...trying to get your bike to run right..thats what he's saying.

 

[TRX2fiveO]

LMAO!!!^^^^^ What are you trying to say Shade? that the dealer tech can only worjk with stock set-up engines??

 

[shadetree]

LMAO!!!^^^^^ What are you trying to say Shade? that the dealer tech can only worjk with stock set-up engines??

lmfao...that's the way it sounded to me !!..rotflmao..why else would he try to get him to go back to a stock air filter ???. you know as well as i do..anytime you mess with the air to fuel mixture,,and go putting after market crap in the engine for more power..it screws up the ratio !!..lol..either that..or the mech needs to quit his job !..lmfao.

 

[Redracer]

The stock filter is not better than a K&N. A K&N breathes much better than the stock foam. This guy just does not know how to jet a machine, he doesn't want to figure it out. He would rather put what the book says in your machine and call it a day. Tell him to come on here and explain to all of us how a filter that doesn't breathe as well as the K&N will out perform a K&N

 

[shadetree]

agreed ^^^^^..thats about how i said it in my first post !..lmaooo.

 

[TRX2fiveO]

But But My service tech teacher said our stock filters were better and the book specs tell us what jets to use and how many turns out the air screw is,if that dosen't work maybe Yamaha dealer can help? LOL

 

[bobami]

Guys I am new to ATV's. I surf this site for shadetee responses to stuff and learn a shit load. Well I notice the old 1994 TRX300FW I am working on has a big ass foam air filter (no idea of the manufactuter) and not the factory air body and filter etc. Should I be concerned? I only will be using this thing for hunting and certainly no high speed operation. This foam filter is impecably clean. I cleaned and adjusted the carb per my Clymer manual and it seems to start good, idle good, and accelerates pretty smoothly.

 

[Redracer]

The foam filter works perfectly, but when you are trying to get performance out of a quad the stock filter just hinders the quad.

Make sure you keep the filter oiled with actual foam filter oil.

 

[09TRX450R]

I understand what everyone is saying and it makes perfect sense but now I wonder if I want this dealer to install the power up kit for me because I know it will be this mechanic doing the job because he has 19 years doing this sort of thing and it seams he’s taking the easy way out and now I don’t trust his word because he also told me that putting a complete exhaust system on the kids 08 trx 90 would do nothing for it. Time to shop around for a new mechanic I guess.

 

[09TRX450R]

Oh and Thank You for all the replies
Rick

 

[838XCracer]

I do think he may have a point. To really get the most out of an engine when building a Killer engine u really need a dyno. U really can't tune a carb by just looking at the plug. U have to take into consideration the pilet jet. My builder had to take the carb off our engine 4 times to get it tuned RIGHT! In this process he gained 4.3 hp. U wouldn't think u could get that much more hp by just changing the 2 jets. But he said to really get them right they both have to work together. Which means u are getting the max hp out of the rpm thru the full powerband.

And I really don't like K&N filters. A UNI is much better in my book. And that is all I have ever run on his quads. Look at it this way. People say a K&N is better because it lets more air in. OK. How does it do it. Answer -The foam is less dense then a UNI. OK. If it is less dense then that means there is more of a chance to get smaller pieces of dirt into the engine.Which means that your piston and valves are going to wear much quicker and loose HP faster and trash the cylinder and valves, which means that u are paying alot more money in the end.

But this is just my 2 cents worth of information on the subject. But this is coming from an engine builder that builds some wicked hp engines.

 

[Redracer]

I never said K&N is better than a UNI foam filter. But to say that you will lose power because he has an aftermarket filter is BS. You are correct the only way to dial in a quad perfect is on a dyno machine, but any skilled tech should be able to jet a quad to get it to perform like it should just by doing plug readings and knowing what the rev should sound and feel like.

Or the techs here are just amazing...

 

[Redracer]

he also told me that putting a complete exhaust system on the kids 08 trx 90 would do nothing for it.

LMAO, the only way a full pipe would not help is if he did not jet it correctly. this guy has been finding the easy way out for 19 years. He is not a tech, he is a direction follower. He can't do anything the book doesn't tell him. IMO

 

[69quadracer]

I use to run a K&N but after running a while when i freshened up the motor the piston skirt was scratched up and i cleaned the filter everytime i took it out, switched to the UNI piston skirt bearly showes any wear, K&N is good for non dusty conditions but my preferance is UNI.

 

[shadetree]

Guys I am new to ATV's. I surf this site for shadetee responses to stuff and learn a shit load. Well I notice the old 1994 TRX300FW I am working on has a big ass foam air filter (no idea of the manufactuter) and not the factory air body and filter etc. Should I be concerned? I only will be using this thing for hunting and certainly no high speed operation. This foam filter is impecably clean. I cleaned and adjusted the carb per my Clymer manual and it seems to start good, idle good, and accelerates pretty smoothly.

more than likely bobami..it's a stock filter..nothing wrong with it. the old saying goes like this.. '' if it's not broken...don't mess with it''..if it is broken...it needed replacing anyway'' !..lol..soo..if your atv is running good right now..leave it be..until it breaks down..don't mess with it..it will run just fine...oh..and thanks for the comment !.i try to help around here as much as i can..just glad it helps ppl like you to work on thier own stuff..and learn about it..that alone is priceless !