air filter

[krotchrocketgrampa]

got an 09 in march of 09, put7,200 miles on it and decided to check filter,WOW !. am amazed at how small it it and how small the intake is.

filter didnt need changing,looked new.I putfilters in my blackbird and my ST1300, they had large air box's and big filters, how dose the fjr get enough air thru it ? mine runs great, had throttle bodies synced when it only had 500 miles,as it kept stalling.any body used any thing else, I'AM SURE THIS SUBJECT HAS BEEN BEAT TO DEATH ALSO, ITS JUST A COMMENT ON SIZE, AND ALL THE BIG GUYS TELL ME SIZE COUNTS

 

[C&C]

Part of the reason is that the FJR has a relatively low redline. The airfilter and snorkel are adequate for the air required. Actually the airfilter is a fairly large surface area, (and as you say the filter looked very clean), it's not being overworked to the tune of loading up (with dirt) quickly.

 

[Geezer]

Some folks like to use a K&N filter. It probably lets more air through, but also probably lets more dirt particles pass through.

I like the oiled foam Uni Filter because I'm a cheap skate and I just clean and oil it once a year and reuse the same filter.

There are even a few folks who have modified the air box for better breathing. You'll have to search for that if you're interested. Lots of reading and various opinions.

 

[TILAM]

Some folks like to use a K&N filter. It probably lets more air through, but also probably lets more dirt particles pass through.
I like the oiled foam Uni Filter because I'm a cheap skate and I just clean and oil it once a year and reuse the same filter.

There are even a few folks who have modified the air box for better breathing. You'll have to search for that if you're interested. Lots of reading and various opinions.

I have to disagree on the K&N front. While it may allow more dirt through my experience is that doesn't relate to engine wear. My old FJ 1200 had one for most of it's 100,000 mile and still doesn't use any oil between changes. My GMC Sonoma has had one too for most of it's 275,000 miles and it too doesn't burn any oil between 5000 mile oil changes either.

I haven't put one in the FJR yet but woouldn't hesitate recommending one based on my experience

 

[Fred W]

Well there you go.

Based on the statistical sample size of one, this scientific conclusion is complete!

It doesn't matter if an air filter filters out the dirt.

Those crazy Japanese design engineers are just trying to limit our fun!!

But I must warn you thusly: There is a direct correlation between the people who chop up their airbox for increased air flow and those who subsequently crash their bikes. We have double the sample size of your experiment in this case (both Wicked Webby and Useless Pickles) so it must be true.

I'm jus' sayin...

 

[ShinyPartsUp]

Well there you go. Based on the statistical sample size of one, this scientific conclusion is complete!

It doesn't matter if an air filter filters out the dirt.

Those crazy Japanese design engineers are just trying to limit our fun!!

But I must warn you thusly: There is a direct correlation between the people who chop up their airbox for increased air flow and those who subsequently crash their bikes. We have double the sample size of your experiment in this case (both Wicked Webby and Useless Pickles) so it must be true.

I'm jus' sayin...

I'll go you one better. Those gentlemen crashed their bikes on two different days of the week, therefore you can only ride your motorcycles 5 days of the week or you WILL crash. You were warned!

 

[RadioHowie]

I putfilters in my blackbird and my ST1300, they had large air box's and big filters, how dose the fjr get enough air thru it ?

Ahhhh, young Padwan learner....do not be seduced by what you can not see.

So think you the FJR airbox small it is?

Again look you must, hmmmmmm?

You know that gigantic area under the rider's seat where a battery would normally go on most motorcycles?

All airbox!

Plus remember, the actual air filter is "rolled up" into a semicircle. Imagine flattening it out and measure the non-pleated surface area alone. It's HUGE!

 

[UselessPickles]

But I must warn you thusly: There is a direct correlation between the people who chop up their airbox for increased air flow and those who subsequently crash their bikes. We have double the sample size of your experiment in this case (both Wicked Webby and Useless Pickles) so it must be true.

I chopped up my air box after I crashed my previous FJR. I did sense that the air box was bad luck, so I did eventually revert back to a nearly stock air box (with stock air filter). I'm glad I did, because Wicked Webby proved that it was just a matter of time before my air box would cause me to crash.

Now for a serious reply:

Yes, more than one person has claimed gains via before/after dyno sessions due to air box modifications.

Here's the simplest mod that allows you to keep a stock air filter: https://www.fjriders.com/forum/showthread.php?t=149

I'm unable to cite my sources, but I remember there being more than one person claiming a small gain across the "entire RPM range" (see below for explanation) with somewhere around peak HP gain of 2-4 HP.

Wicked Webby went insane with his air box mod: https://www.fjrforum.com/forum//index.php?showtopic=102302

He showed additional gains on top of the simpler mod, including a very significant gain in the 4-5k RPM range. I gave this mod a try too, but had some bad luck with my custom air filters getting ingested by the engine. I've now reverted to the simpler mod for reliability and easier air filter changes.

The part that is not certain is how these mods affect lower-RPM performance. Dyno charts often don't start until 3-4k RPMs because... well, I dunno why. Maybe dyno operators assume that people only care about is peak HP, so there's no need to test lower RPMs? My dyno tests when I had the fully modded air box showed a loss of torque below 3700 RPMs as compared to a stock bike (Webby's dyno charts are inconclusive in that range), but I have multiple variables affecting my results because I also have the Holeshot header (Webby had a stock header) and later found very strong evidence that my air filters were over-oiled and may have affected the results (most likely the cause of my loss of peak torque in the higher RPMs, if it affected anything).

I plan on getting another dyno chart with my new air box configuration so see what the difference is. Here's my old results: https://www.fjrforum.com/forum//index.php?showtopic=120164

 

[jwilly]

mine runs great, had throttle bodies synced when it only had 500 miles,as it kept stalling.

Let me see if I got this right, Your bike kept stalling and it was fixed by syncing the throttle bodies? :dntknw:

Did you do the throttle body sync or was this done by the dealer?

JW

 

[Fred W]

mine runs great, had throttle bodies synced when it only had 500 miles,as it kept stalling.

Let me see if I got this right, Your bike kept stalling and it was fixed by syncing the throttle bodies? :dntknw:

Did you do the throttle body sync or was this done by the dealer?

JW

Wild guess here... I'd say the Dealer fixed it with a TBS.

(and part of the TBS is setting the idle speed to 1000-1100 rpm)

 

[krotchrocketgrampa]

mine runs great, had throttle bodies synced when it only had 500 miles,as it kept stalling.

Let me see if I got this right, Your bike kept stalling and it was fixed by syncing the throttle bodies? :dntknw:

Did you do the throttle body sync or was this done by the dealer?

JW

done dealer at 520 miles,under warranty,was way out of sync,goes like hell now

 

[dll]

I just pulled mine to blow it out (per the manual) and all I can say is that on an AE it really sucks to get it out, and it sucks more to get it back in .. I'm hoping to not do that again any time soon