Exaust change and mixture ratio
Welcome guest, is this your first visit? Create Account now to join.

Welcome to the Motorcycle Forum.

Register ButtonIf this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed.

Results 1 to 5 of 5
  1. #1
    Where Am I ?
    My Bike(s)
    2005 C50 (black)
    Location
    Eldersberg, MD
    Posts
    38

    Exaust change and mixture ratio

    I am trying to get a handle on how switching flow via exhaust changes can lean out a bike with either FI or carbs. On intake, the exhaust valve is closed, and vise versa, right?

    Can someone succinctly explain this, or point me to a web site?

    Thanks,

    Joe

  2. Remove Advertisements
    MotorcycleForums.net
    Advertisements
     

  3. #2
    Beer. Nature's Unstoppable Force.

    My Bike(s)
    '06 XB12X
    Location
    2040 N. Dale Mabry Hwy., Tampa, FL 33607
    Posts
    13,226
    Quote Originally Posted by k3new
    I am trying to get a handle on how switching flow via exhaust changes can lean out a bike with either FI or carbs. On intake, the exhaust valve is closed, and vise versa, right?

    Can someone succinctly explain this, or point me to a web site?

    Thanks,

    Joe
    A freer flowing exhaust increases the amount of air flowing through the engine.

    Check this article, it may get you going in the right direction.

    http://www.motorcyclecruiser.com/tech/jetkit/index.html

  4. #3
    Newbie
    My Bike(s)
    BMW R75 w/ sidecar
    Posts
    1
    Quote Originally Posted by intimid8er
    A freer flowing exhaust increases the amount of air flowing through the engine.
    During the exhaust stroke, a free flowing exhaust allow the engine to push the exhaust out with less effort compared to a restrictive exhaust. During the intake stroke, when the engine draws in the air/fuel mixture, the exhaust valve is closed. Whether there is no exhaust or a 30 foot long exhaust pipe with a banana in it won't matter during intake, where the fuel is mixed with air. Please correct me if I'm way off.

    http://auto.howstuffworks.com/engine3.htm

  5. Remove Advertisements
    MotorcycleForums.net
    Advertisements
     

  6. #4
    Newbie
    My Bike(s)
    2005 M50B
    Location
    michigan
    Posts
    12
    I am also curious about this as well because most of the things I have read say how pipes will lean it out but I had an experience with a 1100 vstar that after putting on a hard krome 2into1 it got so rich the plugs had to be changed every couple hundred miles.

  7. #5
    Ditch Magnet
    My Bike(s)
    98 Marauder
    Location
    Central, Pennsylvania
    Posts
    161
    I just put Cobra slash out slip ons on my 98 Marauder. Didnt realy notice that much change in the bike other than the great sound and it being about 20lbs lighter than stock mufflers. I had the local tech have a look at it just to make sure though. He said it realy wasnt that bad but he did tweek the carbs a little. I asked him about rejetting. He said he isnt a big fan of this, unless you cant get the carbs adjusted enough. He told me that he remove the cab slides and shimmed the needles, removed material from the plastic spacers, drilled low speed fuel screws out and readjusted. WHAT EVER ALL THAT MEENS, MAYBE SOMEONE CAN EXPLAIN TO ME. All I know is it run a lot smoother. I noticed before that when I gased on it hard that I felt a low vibration in the bike, now it is smooth and just takes off hard and quik. So I am very happy.
    Hey, just be cool & DONT let your meat loaf!!!!


 

Sponsored Links

 

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Similar Threads

  1. 06 RM 250 fuel mixture
    By adeese660 in forum Dirt Bikes & ATV's
    Replies: 15
    Last Post: 02-04-2006, 04:18 PM
  2. C50 - can you change final drive ratio?
    By opticsguy in forum Cruisers
    Replies: 14
    Last Post: 08-23-2005, 09:05 AM
  3. 1990 RM Fuel Mixture
    By Sicle in forum Dirt Bikes & ATV's
    Replies: 2
    Last Post: 07-28-2005, 03:13 PM
  4. GN250 Mixture
    By crazydaddy in forum Mechanics Corner
    Replies: 0
    Last Post: 07-27-2005, 03:20 AM
  5. Correct Fuel Mixture?
    By crazyman in forum Dirt Bikes & ATV's
    Replies: 5
    Last Post: 05-31-2004, 03:24 PM