Bypass stock airbox with K&N - worth it?

I don't recall if I've asked this before but I've been wondering about it for several years. Either I haven't asked or I don't remember the answer. Anyway...

A number of people messed with adding K&N air filters (and re-jetting) as part of the process of attempting to upgrade the performance of their bikes over the past couple of years. Some later abandoned the attempt because of reliability issues that arose. How many of you ended up being happy with the switch?

Let me clarify my interest slightly. At this stage in the game I'm not interested in upgrading my Chetak's performance. If it gets stronger that's fine. What I am interested in is not having to mess with that damn plastic air intake accordian manifold piece every time I remove and replace my carburetor! I would find it so much simpler just to bypass that piece and the stock airbox altogether and run a K&N filter off the back of my carburetor. But I don't want to hurt the performance, reliability, or longevity of the bike in the process.

From that point of view would you guys recommend the switch as effective and harmless or something to stay away from? If you do recommend it, is it something that realistically should be coupled with a performance exhaust (I still have my POC pipe on a shelf in the garage) or is that part inconsequential?

Thanks,
Marke in OKC

Marke,

I don't remember the stock intake being that much of a PITA, but other than that a pod filter will not harm a thing about your scoot.

Disconnecting the stock airbox means that you have turned OFF the vacuum line to the carb. This changes the way the carb operates and that means you have the block the line and go to a 98 main.. or fabricate the vacuum line into the pod itself and figure out which main jet would be required to compensate for the new inflow or air.

Either way, you then have the scoot setup to input more air easier which is a lot of work and totally worthless if you do not free up the exhaust to expell the increased input.

Thanks to Monza's excellent work and the fact I already had the HRA pipe installed, I podded and switched mains. I love it.

_________________
"I see a big market for designer tin foil head gear..."

"Grow up and stop posting like a 14th Century Vatican Flat Earth Zealot."

About the intake: maybe mine is just worn out but that accordion hood refuses to actually latch itself in place where the intake goes into the body of the scooter. So it is constantly dislodging itself when I remove the carb and the space is small with little rubber lines running here and there and it just frustrates me every time. That's all.

I'm going to go back and re-read the entire original thread about the K&N filter mod before I ask any more questions.

Thanks,
Marke

im sure it has something to do with our different locals but fyi ruffass the 98 was waaaaay to lean for my bike. ive got a 120 and its still too lean.

_________________
Thats a sweet bike.

H-Burg Hooligans.
Harrisburgs Toughest.

http://harrisburghooligans.freeforums.org/

Aggro, there ain't much difference 'tween our locales. If you used a 98 and a 120 main with the same setup there's hardly any way both mains would be too lean. What setup did you use for each?

_________________
"I see a big market for designer tin foil head gear..."

"Grow up and stop posting like a 14th Century Vatican Flat Earth Zealot."

same setup both jets.

_________________
Thats a sweet bike.

H-Burg Hooligans.
Harrisburgs Toughest.

http://harrisburghooligans.freeforums.org/

OK,

But what setup? {sound of pulling teeth Smile

} Inquiring minds might want some factoids with which to anchor their thoughts.

_________________
"I see a big market for designer tin foil head gear..."

"Grow up and stop posting like a 14th Century Vatican Flat Earth Zealot."

haha sorry ruffass.
poc pipe. k&n. tried 98
waaay too lean. my plug was glowing white.

then tried 120. new plug. not as white a little bit of color to it. but still a lil lean.
im just going of plug chops and the way this things been acting.

_________________
Thats a sweet bike.

H-Burg Hooligans.
Harrisburgs Toughest.

http://harrisburghooligans.freeforums.org/

You would think that an approx. 25% change in jet size would have more effect. Particularly when the 120 is for the carb when using the vacuum circuit and the 98 is when the carb is not. It operates distinctly differently in either case, which was the reason for Monza's confusion.

I assume that you are running a thoroughly clean carb. Any chance the gas level in the float bowl is too low? If the top surface of gas is too far from the main jet it gets difficult to suck gas up into the venturi and causes lean running.

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"I see a big market for designer tin foil head gear..."

"Grow up and stop posting like a 14th Century Vatican Flat Earth Zealot."

rufusswan wrote:

You would think that an approx. 25% change in jet size would have more effect. Particularly when the 120 is for the carb when using the vacuum circuit and the 98 is when the carb is not. It operates distinctly differently in either case, which was the reason for Monza's confusion.

I assume that you are running a thoroughly clean carb. Any chance the gas level in the float bowl is too low? If the top surface of gas is too far from the main jet it gets difficult to suck gas up into the venturi and causes lean running.

i did 10 hours on the scoot on sat.
when flying down the super slab wot...it did not like it at all.
would buck and carry on like it was running out of gas.
chatted with a fella and he suggested 2 things.
one pull the vent line from the tank going in to the evap system.
or that it could float level at wot is too shallow.

so im leaning twords that. i disconnected the evap line and to no real difference other than it seemed like my mpg went way down. but my speedo cable broke halfway through the day.

the scoot made it home just fine. this thing does not like the highway. anymore than 20 min of wot and it wanted to overheat. but my first scooter rally was fun. and totally worth it all.

sorry for the sidetrack....its late.

_________________
Thats a sweet bike.

H-Burg Hooligans.
Harrisburgs Toughest.

http://harrisburghooligans.freeforums.org/