'95 900ss carb idle circuit settings - Ducati.ms - The Ultimate Ducati Forum
 
LinkBack Thread Tools Display Modes
post #1 of 8 (permalink) Old Jun 29th, 2012, 10:56 pm Thread Starter
Member
 
jbergen's Avatar
 
Join Date: Jun 2012
Location: San Francisco, CA, USA
Posts: 57
'95 900ss carb idle circuit settings

I've been doing some work on my new (to me) 900sscr which included cleaning the carbs. I'd never cleaned carbs before, but it was full of gelled gasoline(?) and really needed it. I cleaned the jets etc and in the process I'm not sure I replaced the idle jet correctly. Let me explain: as I understand it, the idle circuit is made up of an idle jet and the idle screw. The both are removable, but only the idle screw is accessible from the outside of the float bowl. Now before I fully understood what was going on, I may have misinterpreted the screw settings for the idle screw to apply to the jet. So I while reassembling the carbs I think I set the idle jet 2.5 turns out. I need to go back in to verify this, but before I do, what is the correct setting for the jet? Should it be seated all the way in?

Lastly, in regards to adjusting the idle screw I keep reading that turning the screw out makes the mixture more lean. But it seems to make the mix more rich (sluggish response, higher Rpms, fuel smell in exhaust). Am I just totally backwards?

Anyway I can't wait to get these setting right and get rid of this flat response at the bottom of my throttle!

Thanks!!


Sent from my iPhone using MO Free

San Francisco, CA
'95 900 SuperSport CR
'78 CB400
jbergen is offline  
Sponsored Links
Advertisement
 
post #2 of 8 (permalink) Old Jun 30th, 2012, 2:17 am
Member
 
PeterVentura's Avatar
 
Join Date: Jul 2009
Location: Port Hueneme, CA, USA
Posts: 98
Do you mean the pilot jet inside the float bowls you set 2.5 turns out? that needs to be all the way in snug. The idle mixture screws should be set around 2.5 turns out after lightly seating them.
PeterVentura is offline  
post #3 of 8 (permalink) Old Jun 30th, 2012, 11:52 am Thread Starter
Member
 
jbergen's Avatar
 
Join Date: Jun 2012
Location: San Francisco, CA, USA
Posts: 57
Quote:
Originally Posted by PeterVentura View Post
Do you mean the pilot jet inside the float bowls you set 2.5 turns out? that needs to be all the way in snug. The idle mixture screws should be set around 2.5 turns out after lightly seating them.
After sealing up the bowls and really understanding what was going on in there, that's exactly what I thought. On the plus side, I can now break down and fix my carbs super fast now!

Thanks for the confirmation!! Looks like I've got a little Sunday project ready to go


Sent from my iPhone using MO Free

San Francisco, CA
'95 900 SuperSport CR
'78 CB400
jbergen is offline  
post #4 of 8 (permalink) Old Jun 30th, 2012, 12:45 pm
Senior Member
 
Join Date: Jul 2007
Location: Wilson, WY, USA
Posts: 2,341
Idle mixture screws richen the idle as they are unscrewed, screwing them in makes it more lean (as you noticed).

1997 900 SS/SP track bike
2007 CBR1000RR
1992 CBR900RR (sold)
2005 MV Agusta F4-1000s (sold)
2007 ST3s (sold)
1998 900 SS/FE #299 (sold)
Joe-B is offline  
post #5 of 8 (permalink) Old Jun 30th, 2012, 5:12 pm Thread Starter
Member
 
jbergen's Avatar
 
Join Date: Jun 2012
Location: San Francisco, CA, USA
Posts: 57
Quote:
Originally Posted by Joe-B View Post
Idle mixture screws richen the idle as they are unscrewed, screwing them in makes it more lean (as you noticed).
That makes a ton of sense (in terms of physics too). I must have gotten some bad info or just interpreted it incorrectly. Thanks!!


Sent from my iPhone using MO Free

San Francisco, CA
'95 900 SuperSport CR
'78 CB400
jbergen is offline  
post #6 of 8 (permalink) Old Jun 30th, 2012, 5:56 pm
Senior Member
 
Join Date: Jul 2006
Location: Melbourne, , Australia
Posts: 2,224
i generally replace pilot jets that have been blocked due to their small size and how hard it is to clean them accurately. i'd set the mixture screws at 4 turns out too.

Brad The Bike Boy
www.bikeboy.org
bradblack is online now  
post #7 of 8 (permalink) Old Jun 30th, 2012, 9:17 pm
Member
 
bigbadbass's Avatar
 
Join Date: Aug 2008
Posts: 89
depending upon pilot jet size, a guitar string can "poke " them to spec

available in .001" graduations at your local music store

Also, the pilot path from jet orifice to screw orifice should be blown aggressively from both directions (with diaphragms removed for damage prevention)

as there is a pilot path chamber there you can't see

Beware to assemble the pilot screw orings, washers and springs in correct order

I just split my carbs....new needles, seals , orings to great success

'95 900ss/sp
bass player extraordinaire
bigbadbass is offline  
post #8 of 8 (permalink) Old Jul 1st, 2012, 1:33 am
Member
 
PeterVentura's Avatar
 
Join Date: Jul 2009
Location: Port Hueneme, CA, USA
Posts: 98
Some carbs actually do operate the other way on the idle mixture screws and only control airflow which means turning out would lean the mixture, not ours though. So in a general sense it wasnt necessarily bad info...

Wow guitar strings, good idea!
PeterVentura is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ducati.ms - The Ultimate Ducati Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Idle screw settings 93 900ss!! KIWI900SS Supersport 10 Jun 5th, 2012 12:50 am
1984 600TL Pantah carb settings......HELP! Skidmark Vintage 6 Oct 22nd, 2008 2:13 pm
Bimota DB1 carb settings froryde Bimota 6 Jun 13th, 2008 12:30 am
Stage 2 carb settings? LeoLegend Supersport 0 Feb 10th, 2008 11:30 pm
94 900ss carb problems 94900SS Supersport 1 May 29th, 2006 1:36 am

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

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

 
For the best viewing experience please update your browser to Google Chrome