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CrazyMotorcycleGuy
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Does a new air filter require rejetting the carb?
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Derpetologist
 
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Does a new air filter require rejetting the carb? - April 12, 2011, 10:33 PM

This question just occurred to me. I pulled out the nasty old OEM air filter and put in a fresh Moose racing one... is there a need to rejet?


*Not intended to be a factual statement.
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April 12, 2011, 11:46 PM

How bad are the carb jets now? Is it running rough? Over cleaning carbs will never hurt!
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April 13, 2011, 07:14 AM

Just a filter? No.
Exhaust too? Maybe.


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April 13, 2011, 07:15 AM

You don't HAVE to, but assuming your new filter will let more air through, your air/fuel mixture will change, most likely becoming a little bit lean. Ride the bike and see if you can notice any power delivery problem, popping of the exhaust or excessive heat. Those are all indications of problems. Chaning the jetting/carburation on an engine is not easy, there are a LOT of factors.


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↓ dn ʎɐʍ sıɥʇ ↓
 
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April 13, 2011, 09:07 AM

A performance filter will usually yield less power on a carb'd bike without a re-jet (sometime a simple needle adjustment will fix it). Most tend to stick with the stock filters to save the hassle.

If the Moose Racing filter is relatively close to stock then you should be fine.


-Ryan
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April 13, 2011, 12:57 PM

Well there's a little bit of popping on decel, a little rpm "sticking", and I think the accelerator pump might need adjusting, it is hesitant when I whack the throttle open... not sure if it comes from the new air filter but I guess i should get to a shop.


*Not intended to be a factual statement.
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April 13, 2011, 01:04 PM

Yup.


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April 13, 2011, 01:57 PM

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Yup.
+1


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2006 BMW R1200ST
2003 BMW K1200GT (Current)
2004 Ducati 998s Final Edition (Current)
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1998 Pegaso 650
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2005 Aprilia RSVR Factory
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April 13, 2011, 03:39 PM

If you're not sure what you're doing, then you would want to consider having a shop tune the carbs. If you just changed out the filter and find the bike running a little lean, a simple shimming (or lowering the e-clips) the needles can be suffice.


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April 13, 2011, 09:12 PM

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Originally Posted by Rail View Post
Well there's a little bit of popping on decel, a little rpm "sticking", and I think the accelerator pump might need adjusting, it is hesitant when I whack the throttle open... not sure if it comes from the new air filter but I guess i should get to a shop.
You need the air/fuel screw adjusted. It takes about 10 minutes and the bike will run way better. The stock air box is very restrictive so even the stock air filter is capable of flowing way more air than the small air box ports will allow to enter. The moose filters are awesome and will work well for you. If you need help just pm me.
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April 13, 2011, 09:55 PM

Quote:
Originally Posted by REDLEVEL View Post
You need the air/fuel screw adjusted. It takes about 10 minutes and the bike will run way better. The stock air box is very restrictive so even the stock air filter is capable of flowing way more air than the small air box ports will allow to enter. The moose filters are awesome and will work well for you. If you need help just pm me.
Aren't those adjustment screws normally for the pilot jets and not the mains?


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April 13, 2011, 09:58 PM

Quote:
Originally Posted by REDLEVEL View Post
You need the air/fuel screw adjusted. It takes about 10 minutes and the bike will run way better. The stock air box is very restrictive so even the stock air filter is capable of flowing way more air than the small air box ports will allow to enter. The moose filters are awesome and will work well for you. If you need help just pm me.
Bump for a good dude. If anyone can help you out, it's this guy.


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Im not really fast enough to notice a difference between tires. I buy the kind thats black and made out of rubber.
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April 13, 2011, 10:11 PM

Quote:
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Aren't those adjustment screws normally for the pilot jets and not the mains?
Yep, but a decel back fire with a hanging idle are all signs of a lean pilot circuit
and I'm betting it would clear up the throttle response issue as well.
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April 13, 2011, 10:12 PM

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Bump for a good dude. If anyone can help you out, it's this guy.
Thanks man. Have you had a chance to do any reading in the new book?
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April 13, 2011, 10:23 PM

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Thanks man. Have you had a chance to do any reading in the new book?
Yep, I'm finishing up the first chapter. The book is awesome, I can't wait to start putting some of this stuff to use.



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My wife wants to get LASIK or a boob job

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Im not really fast enough to notice a difference between tires. I buy the kind thats black and made out of rubber.
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