» Sponsors
BikeBanditTrident-Exhausts.comMotorcycle.com

» Sponsors

Hinckley Classic Triples 885cc Classic Styled T3's: Legend, Thunderbird, Thunderbird Sport & Adventurer.

PakBikes.net
Please Visit our Site Sponsors Page

Reply
 
LinkBack Thread Tools Display Modes
Old 06-26-2006   #1 (permalink)
Member
Super Sidecars
 
Join Date: Jun 2004
Location: Rochester, NY
Posts: 55
How does the Air Box and any modifications to it can affect the Vacuum Piston Assembly?

I made some mild modifications to my air box with major performance changes.

First I removed the primary chamber. The one near the battery. The results when poor mid range performance. It spit and sputtered like it was a Rich Mixture.

I replace the primary chamber and drilled some small holes in the air box wear the air filter is located.

The results when the same.

I was just attempting to allow more air to the Crabs because I installed #100 Main jets and TOR exhaust.

Both times as I allowed more air to the carb it responded as it was to rich.

Now for the question,

"How does changing the air flow affect the Vacuum Piston Assembly?" "Why, when adding more air did it then run Rich?"
:hammer:
__________________
David R Greene
Henrietta NY
iamneighbordave@gmail.com
IamNeighbordave is offline   Reply With Quote
Sponsored Links
Advertisement
 

Old 06-26-2006   #2 (permalink)
Senior Member
Formula Extreme
 
Spooner's Avatar
 
Join Date: Aug 2004
Location: Stockholm, Sweden
Posts: 896
What pipes do you have?
__________________
S.P.O.O.N.E.R.

Huh?



Speedy MattHilda & Thunderasaki
Spooner is offline   Reply With Quote
Old 06-26-2006   #3 (permalink)
Senior Member
World SuperBike
Favorite Bike: Mutato -- 2K Adventurer
 
jimmyj900's Avatar
 
Join Date: Apr 2004
Location: Leander, Texas, USA
Posts: 2,476
Quote:
I was just attempting to allow more air to the Crabs because I installed #100 Main jets and TOR exhaust.
The #100 jets are sufficient compensation for the addition of the TOR mufflers and any further mods will require rejetting.

Quote:
I made some mild modifications to my air box with major performance changes. First I removed the primary chamber. The one near the battery. The results when poor mid range performance. It spit and sputtered like it was a Rich Mixture. I replace the primary chamber and drilled some small holes in the air box wear the air filter is located. The results when the same.
By removing the airbox and/or drilling the filter box you've driven your mixture excessively lean. The performance symptoms are the same for either a lean or rich condition -- loss of power and misfiring in extreme cases.

Quote:
"How does changing the air flow affect the Vacuum Piston Assembly?"
The carb slide reacts to the velocity of the air flow through the carb throat and the velocity through the carb throat is determined by the pressure drops in the system.

Every physical element in the airflow path provides a restriction to airflow and introduces a pressure drop across that element. Each pressure drop is also a velocity drop.

Opening up the filter box and/or the inlet system reduces the inlet pressure/velocity drop(s), increases the pressure differential across the carb and the flow across the carb slide increases.

That causes the slide to open faster and the mixture goes lean because the main jet can't supply sufficient fuel for the increased airflow.

I'd suggest you either apply some duct tape over the holes you've drilled or prepare for a lot of carb removals and jet changes.

Jim
__________________
Note: This post may have been altered without the knowledge or consent of the author.
jimmyj900 is offline   Reply With Quote
Reply




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
95 Airbox patrol21 Hinckley Classic Triples 6 01-05-2008 10:17 AM
Airbox apollyun Twins Technical Talk 1 09-26-2007 04:37 PM
Vaccum nipple rubber blew off? riron2001 Twins Technical Talk 13 06-28-2007 12:51 AM
Where does the vaccum hose connect to from the fuel pressure regulator? TiggerTwo Tiger Workshop 3 04-22-2006 10:37 PM
airbox jefftarlton Sprint Forum 9 09-03-2004 04:15 AM


Motorcycle News, Videos and Reviews
Harley Davidson Suzuki GSXR Honda 600RR Yamaha R6
Sportbike Forums GSXR Forum Honda 1000RR Yamaha R1
Sportbikes Forum Ducati Forum Kawasaki ZX R6 Forum
Motorcycle Forum Ducati Monster Kawasaki Forum R1 MessageNet

Powered by vBulletin® Version 3.6.10
Copyright ©2000 - 2008, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.1.0