Carb short fat tubes
04-02-2009, 10:40 AM
#2
Senior Member
MotoGP
Join Date: May 2008
Location: San Clemente, CA
Posts: 3,451
Short one in front, and longer one in back both held by 4 screws?
If those are what you are talking about, they direct airflow into the carbs. Basically they are velocity stacks. Without them air would not flow as efficiently into the carbs and you would lose performance.
If those are what you are talking about, they direct airflow into the carbs. Basically they are velocity stacks. Without them air would not flow as efficiently into the carbs and you would lose performance.
04-02-2009, 12:13 PM
#4
Senior Member
SuperBike
Join Date: Jan 2007
Posts: 2,116
I believe they draw filtered crackcase oil blow-by vapor into the carbs to be burned and thus reduce emissions. Do not plug or remove these tubes/connections, they have no detrimental effect on performance. The crankcase breather tubes from each valve cover vent into the airbox through the sub air filters, which also must be cleaned and reused. Wipe excess oil from the bottom of the airbox and gently brush & blow clean the main air filter. The main filter can also be gently washed and rinsed clean (but not soaked) with Dawn type grease cutting dish detergent and H2O, and air dryed.
04-02-2009, 12:18 PM
#5
Senior Member
MotoGP
Join Date: May 2008
Location: San Clemente, CA
Posts: 3,451
skokievtr is right. If you disconnect those pcv tubes, you will have oil everywhere. If you plug the pcv outlets from the engine, you will build up crankcase pressure and blow out oil seals. The positive crankcase ventilation system does just what it says. No performance loss.
04-02-2009, 12:49 PM
#9
Senior Member
SuperBike
Join Date: Jan 2007
Posts: 2,116
skokievtr is right. If you disconnect those pcv tubes, you will have oil everywhere. If you plug the pcv outlets from the engine, you will build up crankcase pressure and blow out oil seals. The positive crankcase ventilation system does just what it says. No performance loss.
04-02-2009, 12:52 PM
#10
Senior Member
MotoGP
Join Date: Mar 2007
Location: Phoenix, AZ
Posts: 3,132
From what I can tell the ones on the swivels are the PVC vent tubes..
http://fiche.ronayers.com/Index.cfm/...up/AIR_CLEANER
The ones not on the swivels are for PAIR
http://fiche.ronayers.com/Index.cfm/..._SUCTION_VALVE
Although I could be misreading that, I don't have my bike apart either.
http://fiche.ronayers.com/Index.cfm/...up/AIR_CLEANER
The ones not on the swivels are for PAIR
http://fiche.ronayers.com/Index.cfm/..._SUCTION_VALVE
Although I could be misreading that, I don't have my bike apart either.
04-02-2009, 02:33 PM
#11
Senior Member
SuperSport
Thread Starter
Join Date: Jun 2008
Location: San Diego
Posts: 916
He was talking about the carb intake vent tubes & joint sets, which are items #21 & 5 in this link, not the PCV tubes & other airbox components. http://fiche.ronayers.com/Index.cfm/...ARBURETOR_ASSY
Yes that is what I am talking about.
04-02-2009, 05:32 PM
#13
Senior Member
SuperSport
Join Date: Nov 2007
Location: Hamilton, Ontario, Canada
Posts: 807
As VTRsurfer said, they're vents for the carb diaphragms. If you take off the air box lid and remove the air filter, you'll see two roughly triangular boxes at the front and the back of the air box base. There are little foam filters in the boxes. The carb diaphragms displace air as they lift and lower the carb slides. Air is drawn in or pushed through the little foam filters as the slides move.
The crancase vents from the cylinder head covers directly into the air box.
The crancase vents from the cylinder head covers directly into the air box.
Thread
Thread Starter
Forum
Replies
Last Post
