making the commando stock air filter smaller, has anybody?

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david7212

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Wouldn't it be nice if the stock air filter and grill was about an inch less deep and add the same inch onto the gators thus changing the stock air filer or working on the carbs would be so much easier. I realize the K & N set up would eliminate my troubles although I will always prefer the look of the original set up...just wish the original engineers had thought of this. Has anybody ever reduced the size of the filter and grill?
 
Re: making the commando stock air filter smaller, has anybod

david7212 said:
Wouldn't it be nice if the stock air filter and grill was about an inch less deep and add the same inch onto the gators thus changing the stock air filer or working on the carbs would be so much easier. I realize the K & N set up would eliminate my troubles although I will always prefer the look of the original set up...just wish the original engineers had thought of this. Has anybody ever reduced the size of the filter and grill?
Click to expand...

Smaller = slower.

Remember that there's a K&N for the stock airbox.
 
Re: making the commando stock air filter smaller, has anybod

I have a 70 commando, even with a K & N element for the stock set up, it would still be a pain in the rear to install the gators. Am I the only one who has difficulty? if there is a K & N for the stock set up, and knowing the K & N has better air flow than a stock filter, couldn't the K & N be cut down and still out perform the stock filter?
 
Re: making the commando stock air filter smaller, has anybod

I thought about this several years ago, and figured I'd first look for a shorter filter. I looked around for a filter that would fit and couldn't find any - I went through several hundred boxes at my local auto parts store. Then there's the hassle of making longer gaitors. I figured I'd just get the knack for installing the carbs. I can usually get them in in less than 10 minutes. This is for the 'canned ham' air cleaner used for most stock Commandos.

Assemble the air filter with the gaitors
Assemble the carbs to the manifolds
spread a little dielectric grease to either the mouth of the carb or the inside of the gaitor.
Using a cotter pin puller like this:
making the commando stock air filter smaller, has anybody?

to help work the gaitor onto the mouth of the carb, slide it into place and install the allen screws - don't forget the heat insulator!

Repeat for the second carb. Some have cut the inner mounting hole on the second carb into a slot, so the allen and insulator can be installed before sliding the carb into place. then its just a couple of turns with the special short allen wrench to cinch up the inner mount.


Actually, the air cleaner on the P11 is pretty nice. There's less room in that bike than on the Commando, yet the air cleaner is pretty substantial and quite easy to install. The front plate of the cleaner slides over the mouths of the carbs and is held in place by those threaded rings. Then the filter and mesh go on, followed by the back plate. A nut and bolt running through the center of the cleaner holds the whole thing together. There's no vent tube, as the P11 just ran the vent out under the rear fender.
 
Re: making the commando stock air filter smaller, has anybod

thanks for the response...according to the link below, the P-11 is about 7/8 of an inch thinner than the commando filter although it's also about an inch less outer diameter thus it may not fill up the filter housing / canned ham container. are these filters flexible? as the pictures show round filters for both bikes, does it contort to the oblong shaped housing once pushed inside? thanks again.


http://www.britcycle.com/products/K&N/KNProducts.htm
 
Re: making the commando stock air filter smaller, has anybod

I shortened mine to fit my Kehnins. Used a K&N element. I cut down the grill/surround with a Dremel tool with a router base to keep the cut even and used shorter screws to hold the assebly together.
making the commando stock air filter smaller, has anybody?

JD
 
Re: making the commando stock air filter smaller, has anybod

that's what I'm referring to by cutting down but now my questions are;

what specific K & N filter are u running? did u have to trim or reduce the size of the filter? if so, how?
even though u reduced the dept of the filter, it seems like u still have a similar distance between the carbs and the filter plate thus the same difficulty is present regarding taking the filter or carbs on and off, correct?

thanks for the great photo.
 
Re: making the commando stock air filter smaller, has anybod

Just a thought - I struggled for a long time getting the rubbers between airbox and carbies installed after I had installed the airbox - UNTIL - I, finally, RTFM(Read The F...ing Manual). Installing the rubbers and front plate to the carbies first and then feeding the element with grill surround betwwen front and back plates proved relatively simple compared to the years of pain I had endured by neglecting the manual!! (sometimes I astound myself!!)
Cheers,
Dave
 
Re: making the commando stock air filter smaller, has anybod

RGM is selling a filter and grille one inch less than standard (reference is 060816N) . So it seems the idea came to several people. I guess they use a standard air filter element , and can provide a reference .
 
Re: making the commando stock air filter smaller, has anybod

Some years ago, when I decided to try a single carb setup, I found that I HAD to have a thinner air filter as the manifold sets the carb further back. Maybe that's why RGM supplies the thinner filter.
What I did at the time was to make my own parts:
perf. metal outer cover.
expanded metal inner retainer.
front plate with single hole.
The filter was a foam Unifilter, part No. NU 6001, cut down to size.

Cheers
Martin
 
Re: making the commando stock air filter smaller, has anybod

I want to have the ham can back and it seems like Jeff Davison, who's bike is pictured, did what I want to do.
This is an old thread but back then he didn't answer the question of, "What filter did you use?"

I tried to PM him but haven't got a reply.
I really would like to either talk to him or someone who has done this mod before.
I called K&N and they couldn't help me.
I'll call RGM and see if they sell the filter.
 
Re: making the commando stock air filter smaller, has anybod

David, are you still using the original carbs. If so, it is really easy to change that filter. What I do is place a piece of cardboard box over my primary housing to prevent scratching. I then [ after removing the bolts,] compress the front plate forward. This allows the air filter and gauze to rotate out and over the primary housing. How you hold the front cover forward is up to you, but I usually yell out for help from one of my sons. No reason why a piece of string going round the front of the head could be used to hold that front filter plate forward. Hope this helps. Dereck.
 
Re: making the commando stock air filter smaller, has anybod

Guido said:
I want to have the ham can back and it seems like Jeff Davison, who's bike is pictured, did what I want to do.
This is an old thread but back then he didn't answer the question of, "What filter did you use?"

I tried to PM him but haven't got a reply.
I really would like to either talk to him or someone who has done this mod before.
I called K&N and they couldn't help me.
I'll call RGM and see if they sell the filter.
Click to expand...

RGM supply a narrow gauze and a matching filter:

http://www.rgmnorton.co.uk/buy/air-filt ... 9_1672.htm
http://www.rgmnorton.co.uk/buy/narrow-v ... 9_1674.htm

Also available as a complete assembly in stainless. Not very cheap, but not expensive for what you get either:
http://www.rgmnorton.co.uk/buy/complete ... l_3693.htm
 
Re: making the commando stock air filter smaller, has anybod

check your in box.

JD

Guido said:
I want to have the ham can back and it seems like Jeff Davison, who's bike is pictured, did what I want to do.
This is an old thread but back then he didn't answer the question of, "What filter did you use?"

I tried to PM him but haven't got a reply.
I really would like to either talk to him or someone who has done this mod before.
I called K&N and they couldn't help me.
I'll call RGM and see if they sell the filter.
Click to expand...
 
Re: making the commando stock air filter smaller, has anybod

Smaller = slower.

Remember that there's a K&N for the stock airbox.[/quote]

yes and what a piece off shit that is. Do you want to buy mine.
 
Re: making the commando stock air filter smaller, has anybod

K&N Norton spec'd Filter:

K&N NO-0100
Height = 2.875"
Inner Diameter = 6.875"
Outer Diameter = 8.125"

What I used with the shortend assembly:

K&N E-2570
Height = 1.875"
Inner Diametr = 6.25"
Outer Diameter = 8.188"

Where I ordered it from:

http://www.summitracing.com/parts/knn-e-2570

Can flow all the CFM the engine can use and then some. No problems with restriction (unless you have the ultimate flowed, ported, cc'd overbored race engine)
Fine for my stock 850 with the FCR's and more CFM that the individual filters that are supplied with the FCR kit.



JD
 
Re: making the commando stock air filter smaller, has anybod

I'm late in here, but.........

It's Norton we are talking about here! A bit like working on a MK11 Jag, hehe.
One trick I use to service the air filter, I have a piece of teflon, that I place in front of the rubber gators, just before I slip in the filter end plate.
I must admit I did have to swap out the original MK11 filter end plate with the deflector part on it though.

Now, how do I remove the horn without doing a complete ground up restoration?

Richard
 
Re: making the commando stock air filter smaller, has anybod

horn, removal quick. remove rear wheel. undo front bolts on rear guard and rotate guard down. easy. easier still, fit another horn by the battery. 2 tones sounds great.

Cant understand why this discussion is still going on regarding the air filter when I have already suggested how to change it easily. Maybe its because DIY have 2 left hands. Leave the bloody thing alone.
If its not broken, don't fix it.
 
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