Whats up with K&N's

[mcmuck]

Hi Folks! so at the risk of starting something akin to an oil thread, every Guzzi I see including the Spada I have has had the stock airbox pitched and K & N's installed. I have two questions.
1) Do they run ok without major rejetting? like changing slides to get the correct cutaway etc and by ok I mean as good as factory? Was Factory seamless as it should be?
2) Advertised fuel mileage was 50 mpg on a us gallon what are people hoping to gain?
Well..... maybe more than two questions : )

[Dave Swanson]

In my opinion the main reason for the change to pods is ease of filter service.  The airbox is quite fiddly when changing the filter.  K&Ns can be taken off, cleaned, and reinstalled in less than 1/2 the time. 

I converted my 1000S back to the airbox from the way it came to me with K&N pods.  I prefer the extra support the carburetors have when using the airbox. 

[yogidozer]

Dave has some good points, but I would try to find the original airbox.
You don't need to check the filter all that often, and gives you something to do off season.
Besides the additional support needed for the K&Ns, they aren't weatherproof.
And let's be honest, we all get caught in the rain.
Changing just the filters to K&Ns, isn't going to give you 100 more ponies.
JMO

[guzzista]

Proper K&n filter cleaning includes soaking in own cleaner/ water mixture ( liquid dish soap will substitute finely> Guzzi content) rinsing, air drying (no air blast allowed) , then re-oiling, then installing. Won't be that fast under any circumstances unless you compare it to ovenight shipping, then it's about as fast

[Idontwantapickle]

You can probably find the airbox parts you need from Harpers or MG Cycle

http://www.harpermoto.com/parts-lookup/1990-1999-moto-guzzis/strada-1000-1993-1994/air-filter-en-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20-21-22-23-24-25-26-27-28-29-30-31-32-33-34-35-36-37-38-39-40.html

http://www.mgcycle.com/index.php?main_page=product_info&products_id=4604

The stock airbox has many advantages including a cooler intake point, a filter with larger more effective surface area, and as yogi mentioned it's weatherproof. Oh, and it's quieter too if that matters to ya.
My LeMans is very happy with the stock airbox.

Hunter

[Stevex]

Removing the airbox and OEM filter and replacing with K&Ns will require re jetting/ carb tuning. I speak from experience many years ago on a V50.
I'm also not convinced at K&N's filtering efficiency and all my bikes now run on oem (paper) air filters.
OEM filters are designed not only to filter highly efficiently but also flow more air than any engine will possibly require to produce it's peak bhp.

[John A]

Do they still say in the instructions that they filter better when dirty?

[Vagrant]

All filters oil, gas,air filter best when 1/2 dirty. That's how they are designed.

[dxhall]

In my experience, the stock airbox outperforms the KNs.

My LM V had small pod filters when I bought it.  It ran OK, but not great.  Spark plugs were the usual brown color.

I reinstalled the stock airbox and put a KN filter in the stock filter frame.  The bike wouldn’t rev past 5000 rpm.  Spark plugs were white, indicating a serious lean condition.  What happened, then, was that the stock box w/ KN flat filter was flowing so much more air than the pods that the old jets were too small.

I think pod filters, especially the small ones, are a bogus mod.

[Tom]

Most people think that it's more efficient and a good modification for a motorcycle.  They don't do the rest of the modifications....ex haust, fuel & timing etc. and dyno test to see if all the work is worth it.  IMO biggest mods are fuel intake adjust. &/or timing.

[Kiwi_Roy]

I had K&N pods on my VII Sport for a while, it had a definite flat spot mid range without the rubber Velocity stacks of the airbox, after a few years the pods looked decidedly grubby so I put the airbag back, been there done that, learnt the Guzzi designer knew what he was doing,

[Antietam Classic Cycle]

'70s Guzzis such as the T3 and Convert had a such a piss poorly designed airbox, that even I ditched it and fitted K&Ns. The one on the square-fin models is much better and I'd keep that, but the early one really sucks.

[PeteS]

The few tests I have read comparing filters show K&Ns don't flow significantly more air than stock paper filters.
I use them because its a one time expense. Guzzi sold the 850 LeMans with velocity stacks, no filters so it wasn't a difficult decision to go with K&Ns.

Pete

[mcmuck]

I suspected as much. I use a K & N filter in my R75/R90 and when I changed over I had to go up 5 main jet sizes, I also changed slides to change the cutaway to a richer one and eventually changed emulsion tubes to correct the mixture at 1/2 and 3/4 throttle settings. I have 38mm Mikuni's on it and made these changes over several years. I have almost seamless carburation but it wasn't easy or quick. K & N recommends a cleaning interval of something like 30,000 miles and yes the say they need the dirt to occupy space in the gauze fir better filtration. One more thing to source : )
Thanks for your help with this!

[mcmuck]

Dave, Very nice job on your bike, very tidy!

[Rough Edge racing]

I suspected as much. I use a K & N filter in my R75/R90 and when I changed over I had to go up 5 main jet sizes, I also changed slides to change the cutaway to a richer one and eventually changed emulsion tubes to correct the mixture at 1/2 and 3/4 throttle settings. I have 38mm Mikuni's on it and made these changes over several years. I have almost seamless carburation but it wasn't easy or quick. K & N recommends a cleaning interval of something like 30,000 miles and yes the say they need the dirt to occupy space in the gauze fir better filtration. One more thing to source : )
Thanks for your help with this!

  So explain why you had to go up 5 jet sizes and other richer jet settings with the K&N? It must not be due to more air flow because most say they don't flow more air...So whay the changes?

[SED]

Carbs droop when K&Ns are combined with rubber manifolds.  They get grungy looking very quickly.  Reportedly the stock LMIII airbox is "tuned" to maximize intake performance.  After trying to like the K&Ns for years and even buying new I collected all the parts to replace the missing stock airbox. 

[mcmuck]

Hi Rough edge racing! K&N's flow a ton more air than the paper filter, I'm sure one of the Engineers could figure out the %.  Paper is an excellent filter but very restrictive as compared to the gauze k&N you only have to look through a freshly washed one to see what I mean. In my case I was prepared to accept the consequences. Most people are unaware, If you live in a humid climate it's not as much of an issue as there's not the find dust in the air we have here, we are in a semi desert climate. 

[John A]

All filters oil, gas,air filter best when 1/2 dirty. That's how they are designed.

that's been obvious for along time   
can you answer the question?  Im just curious, I've not seen that on paper filters

[guzzista]

'70s Guzzis such as the T3 and Convert had a such a piss poorly designed airbox, that even I ditched it and fitted K&Ns. The one on the square-fin models is much better and I'd keep that, but the early one really sucks.

. Ditto as on the SP. A miserable experience and not much airbox volume to speak of.  Another option that has worked well for me are the Unifilters. Foam does filter better than gauze and, for the price, you can just toss them (not Guzzi content) after a couple years if you dont feel like cleaning them or they deteriorate.

[Rough Edge racing]

 If you have pod filters with rubber mounted caburetors it's very easy to rig a support to prevent the droop...It can be as simple as a length of wire or a large o ring..
 

[Tom]

+1

[Idontwantapickle]

the early one really sucks.

Ha! I love Charlie's subtle humor.

[mcmuck]

Managed to find a stock airbox setup for a "reasonable" price, it's on it's way : ) One down!

[not-fishing]

Proper K&n filter cleaning includes soaking in own cleaner/ water mixture ( liquid dish soap will substitute finely> Guzzi content) rinsing, air drying (no air blast allowed) , then re-oiling, then installing. Won't be that fast under any circumstances unless you compare it to ovenight shipping, then it's about as fast

And letting them sit overnight on a paper towel as excess oil drains off otherwise it just goes downstream and gums up everything

It took me a long while to learn this.  although it still goes downstream and clogs up everything

[John A]

there are two reasons I don't use them unless there is no other option.
Fire, they burn well.  I almost lost a hotrod Dodge when it popped back and lit an expensive KN up.  usually if the engine starts you can just suck it out but this thing didn't want to start. Hilarity ensued....
then they don't filter well,  the evidence I've seen is a high silica [dirt] content in oil analysis tests when I was party to that on several aviation engines installed on experimentals.  so its not apples vs apples but talking with engine builders they found it common.
I prefer a paper filter and like a foam covered KN if I have a fire extinguisher handy.