[saint45]

I have a G5 and am wondering if anyone has upgraded to the K&N. Worth it?

[gremlin]

nah, it's one of those things you do.   No real benefit & it costs as much as 5 of the stock air filters.

[Lwt Big Cheese]

If you want more crap entering your engine go ahead. Some prefer the style regardles of what may enter. Remember lots of people have no filtration at all, just bell mouths.

See the threads on oil where hours are wasted on arguing over very little. Where some insist on oil A over oil B because of increased engine longevity, then put a K&N on where the filtration isnt as good as stock.

Pays your money takes your choice.

[hortoncode3]

If I had to to do all over again i wouldn't have bothered. No noticeable increase in performance and you still have to buy cleaners and such for the "reusable filter"..it's not worth it. Plus it's fit is sucky.

[barenekd]

I like mine, It fits good, filters well and makes some nice carb sucky noises.
Cleaning costs a lot less than a new filter, and I won't need to probably ever replace this one.
But you pays your money and makes your choices.
Bare

[AVL Power!]

I like the UNI Filters. Foam type and never faced issues with those filters even in rain. Did a 300km trip in rain and without any issues.

Also, I used K&N for sometime and didn't like it at all. My carb's slide was covered with dirt... even when it was oiled properly! UNI doesn't do that to me atleast.

-Sanket

[barenekd]

I used to put Unis in Triumphs back in the day. I definitely found that they didn't flow as much air as the stock air filters. Some of the Triumphs would not run at top end with them. Totally cut out. I quit using them.
Bare

[saint45]

Thanks a lot to all you guys! I'll leave well enough alone.
I had just heard you should do it with the EFI pipe, which I have.

[AVL Power!]

I used to put Unis in Triumphs back in the day. I definitely found that they didn't flow as much air as the stock air filters. Some of the Triumphs would run at top end with them. Totally cut out. I quit using them.
Bare

I heard about that a lot.. so what if I run the UNIs without the oil? will it let dust particles in? Never tried that


-Sanket

[barenekd]

Yes, the dust will go right through.
Bare

[Arizoni]

The dust can go thru a un-oiled K&N air filter but the instructions say to oil it with their (high dollar) oil.

The first time I oiled the K&N I bought, my G5 had a very noticeable drop in power so I removed the filter and did a (home made) air flow test on it.
With the oil applied as it was, it was about twice as restrictive as the stock paper air filter.

Using K&N's degreasing fluid to remove the oil, I applied just a hint of oil to the filter and tried again.
My airflow test showed that the K&N was now, less restrictive than the stock paper filter so I thought I was on the right track.
I reinstalled the K&N in my G5 and buttoned it up.

My seat of the pants dynometer told me that most but not all of the horsepower had returned.  This was most noticeable at high rpm's where the engine seemed to run out of wind.
 During the next tank of fuel my fuel mileage dropped a bit.

Without some elaborate test equipment and a transparent air box that duplicates the stock one on my bike, I'm guessing but I decided that the larger, tapered body of the K&N filter was actually decreasing the open area into the throttle bodys intake.
In other words, the filter body, being larger placed it right up next to the air intake causing it to restrict airflow into the engine.

Following this experiance, I replaced my old paper filter.
The engines power seemed to return and the old fuel mileage did return so that's the filter I'm now using.

Others results may vary.

[ace.cafe]

I'll cast my lot in with the paper filter people.

But you have to change them out regularly, or they'll plug up.

[barenekd]

I have a parallel sided K&N in mine. A lot more area than the tapered one.
I can't say it adds any power, but I never felt like it lost any.
Bare

[AussieDave]

On account of the very small holes in the hydralic lifters i reckon it might be wise to stay on the clean side ....I've read mixed reports about the k&n... whats the consensus?

[AwL]

Since installing K&N filter on 2009 G5 have noticed an irritating high pitched whine when engine under load (55 mph with sidecar).  Going back to the stock filter...

[barenekd]

I like mine.
Bare

[trimleyman]

Changed to a K&N a few months ago and have to say the overall performance is slightly improved. I keep it well oiled with K&N's red stuff , but not over-oiled. I had not replaced the OEM paper filter as I had always been able to keep it clear with a regular reverse blast of compressed air. As most of my previous machines had been free breathing with nothing to restrict them filling their lungs or emptying them for that matter I find the K&N quite satisfactory . Bought the one I have from a supplier in Lebec, CA only to find I pass their store a couple of times most months.

[Fogrunner]

Installed mine about 1500 kms ago, and have had no problems, or fuel mileage decrease. I do think the performance has improved.

[jartist]

I had problems with the paper oem filter getting contaminated with engine oil and clogging. I don't get engine oil in the airbox with the k&n even if the crankcase is a tad overfilled.

[suitcasejefferson]

I'm new here, and this is only my second post, but I couldn't resist when I saw those infamous letters K&N. I am a professional auto mechanic and amateur drag racer (cars). K&N filters (if you can even call them filters) are race only parts. I use one on my race car, which was built and tuned for as much airflow as possible, but I would never even consider using one on a street vehicle, car or bike. Not only do they flow a lot more air, and totally mess up your air/fuel mixture, but they also flow about 10 times more dirt than most stock filters. It the closest you can get to running without a filter. Many racers refer to them as KILL your engine NOW filters. For some reason people think if they install a few race parts on their street vehicle it will be faster or something. But even if it was, it would not be worth the drastic decrease in engine life caused by using K&N filters.

Uni makes a pretty decent filter, I have used them on dirtbikes. I soak them in engine oil, and clean and reoil them after every days riding. But for long engine life, unless you plan on doing a lot of cleaning and oiling, nothing beats a stock filter.

[GreenMachine]

Suitcasejefferson:  I won;t argue that point..It makes sense either way..K&N breathes easier but you increase the amount of contamination...I still have the stock filter in a box somewhere..I installed my K&N 8 years ago and clean/oil it once a year. I'm only average 1-2k a year anyway but some of the guys are averaging 8-10k  a year and I suspect maintain their filters more often...
Ace fabricated a cylinder shape air chamber that used a paper filter for filtration and seem to get good results..Not sure if he's still doing it gig anymore...
On my vehicles I use just stock filters period and just changed them per the manufacturer spec...
I'm not a big fan of aftermarket bolt on stuff anyway but their are occasion like the Jardine oil relocation kit that comes in handy when changing the oil on my yamaha. I wonder if the oil flow is affected even minimally by that contraption?  Welcome to the board ....GM