'core-ing' og. mufflers/k&n air filters ???'s

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schrader7032
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Joined: Fri Oct 27, 2006 3:00 am
Location: San Antonio, TX

'core-ing' og. mufflers/k&n air filters ???'s

Post by schrader7032 »

What are you looking to "make better" with this mod? Just curious...

My opinion is that the K&N filters are not good for the top end, letting in too much grit. People use them to let the engine breathe better, but to do that requires that the filter mesh be larger than the stock paper filters. Plus, they don't really work best until they accumulate a fair amount of oily grit on the mesh. For some reason that just doesn't make any sense to me.

These bikes don't really have the kind of horsepower to tap into. Often times, people through money or effort at the bike but don't find any measureable differences. Maybe at the upper end of the RPM band, but not many people I know try to operate these bikes there for very long.

Sorry, no help with your questions, but good luck with your mods.

Kurt in S.A.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

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VBMWMO
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Joined: Sun Aug 23, 2009 7:49 pm

'core-ing' og. mufflers/k&n air filters ???'s

Post by VBMWMO »

I am looking for some advice on core-ing my og. mufflers and doing a K&N air filter upgrade with the single filters for each carb.#1 what hole saw size do you rec.? #2 Have you had to re-jet the carbs w/ just the mufflers being done? #3 what about the mufflers and the air filters(using K&N individual filters?

Any advice would be appreciated. Thanx. Airhead
Dedicated to the Preservation of Classic and Antique BMW Motorcycles.

mymindsok
Posts: 5
Joined: Fri Feb 26, 2010 8:41 pm

K+N filter pogs are great as

Post by mymindsok »

K+N filter pogs are great as long as you can put up with a drop in horsepower...

Airheads benefit from a long intake tract and the air-box does have a positive effect on power and torque production. In fact, if you really want some cheap horse power, install one of the square air-boxes with the plastic horns on your bike. That can be worth as much as 2 HP under the right conditions. No kidding...

You can also pick up a little power on top if you drill a hole in the baffle but you'll have to get back t me about the exact dimension, cause I just don't feel like looking it up right now.

Unfortunately, most of the stuff that guys do to increase the performance of Airheads, just make the bikes run slower and wear out faster.
Mymindsok

Airhead #85

airhead
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Joined: Thu Jan 14, 2010 6:59 pm

thanx

Post by airhead »

thanx for the advice...i am actually leaving the bike stock. i decided not to mess w/ anything.

Jake
Posts: 14
Joined: Sun Jul 12, 2009 9:41 am

K&N air filter

Post by Jake »

Hi - I'm a few months late to this party - but had been wondering about putting K&N in my 75/7 project - but I'm more in line with the comments here. In the past putting K&N filters on underpowered machines has not given me any benefits - so glad to catch this thread.
Jake

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