Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 911 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Mar 2003
Location: Seattle, WA
Posts: 176
Weber idle jet O-ring?

Hi,

Forgive me if this is a stupid question. I have rebuilt my webers (40 IDAs) on the 68 911 that I purchased approximatley a year ago. I am having trouble getting the mixture set. While cruising through other posts I noticed someone made reference to an O-ring around the idle jets.

The carbs did not have o-rings installed around the idle jets when I started the rebuild, the only o-rings present where on the air/mixture screws. Do I need to have o-rings around the idle jets? If so, that would probably explain why I am having a bit of difficulty setting the mixture screws at 1200 rpms.


Thanks
________________________________
206aa
1968 Porsche 911 (2.4T)

Old 12-22-2003, 02:29 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered User
 
Join Date: May 2001
Posts: 7,492
Garage
There are definitely O-rings around the idle jets. Not sure how the lack of same would affect the mixture screws though.
Old 12-22-2003, 02:33 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
rickeolis's Avatar
 
Join Date: Feb 2002
Location: Near Albuquerque, New Mexico
Posts: 1,076
Porsche Crest

I wish I had the legend that came with this, but here you will see #37 which is a rubber O-ring, which gets covered into place by the next item #36; this is a concave cap which the spring pushes against. Pelican's rebuild kit has the new O-ring's in it, but not the caps or springs.






Hope this helps some-
__________________
-Rickeolis-

1986 Corvette
Old 12-22-2003, 02:37 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Unoffended by naked girls
 
dhoward's Avatar
 
Join Date: Sep 2002
Location: St. Charles, MO
Posts: 5,894
Garage
Send a message via AIM to dhoward
Number 37 goes around the mixture screws. I had the same question as I have to blow dirt out of my idle jets every so often (gotta get those PMO fuel bars and filters!). The drawing I had from Rennlist was very poor, and I didn't see a washer on the idle jet holder (which I think 206aa was referring to) Looks like #25 on your drawing. My guess is not o-rings, but fiber washers?
__________________
Dan
1969 911T (sold)
2008 FXDL
www.labreaprecision.com
www.concealedcarrymidwest.com
Old 12-22-2003, 03:01 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Mar 2003
Location: Seattle, WA
Posts: 176
Rickeolis,

Thanks for the reply! Great picture by the way, most I have seen aren't as clear as yours. I was talking about the idle jets not the air mixture screws. So my question would be, is #25 rubber or brass?

I thought I had read somewhere that if air is making it in around the idle jets then it would be difficult to tune. I have rubber o-rings installed for #37. Perhaps they are the wrong size and air is coming in there? Anyway, turning the air mixture screws in , makes little difference until they are almost all the way in. . Does this make sense at all? Thanks for the help!

206AA
Old 12-22-2003, 03:05 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
Join Date: Mar 2003
Location: Seattle, WA
Posts: 176
From dhowards post: "Looks like #25 on your drawing. My guess is not o-rings, but fiber washers?"

This is exactly what I was referring to. Fiber eh?
Old 12-22-2003, 03:06 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered User
 
Join Date: Mar 2003
Location: Seattle, WA
Posts: 176
Thanks to everyone who replied. I think I am going to try the rubber o-rings and see if they help. .
Old 12-22-2003, 11:34 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
Join Date: Jul 2001
Location: Portland Oregon
Posts: 7,005
Ohhhh, yessss,..they WILL help a lot.

One cannot adjust idle mixture on these carbs without these rubber O-rings on each idle jet holder.
__________________
Steve Weiner
Rennsport Systems
Portland Oregon
(503) 244-0990
porsche@rennsportsystems.com
www.rennsportsystems.com
Old 12-23-2003, 12:14 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Unoffended by naked girls
 
dhoward's Avatar
 
Join Date: Sep 2002
Location: St. Charles, MO
Posts: 5,894
Garage
Send a message via AIM to dhoward
The pages in my "101 projects" are all stuck together.....
__________________
Dan
1969 911T (sold)
2008 FXDL
www.labreaprecision.com
www.concealedcarrymidwest.com
Old 12-23-2003, 04:27 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Registered User
 
rs911t's Avatar
 
Join Date: Sep 2002
Location: Leesburg, VA
Posts: 1,206
Garage
YES you need rubber O-rings on the idle jets and you won't find them in any of the pictures (at least, the one's I've seen). Go down to your local auto parts store and get 008 o-rings.
__________________
Greg
1972 911T
TrackVision
Old 12-23-2003, 05:39 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Registered User
 
Join Date: Mar 2003
Location: Seattle, WA
Posts: 176
Interestingly enough, the illustration in "101 Projects. ." doesn't show an O-ring, or any type of washer for that matter. The above picture definetly does show something. Anyway, hopefully installing the O-ring as Greg suggested will remedy the problem and I will be able to set the mixture. If not, it might be time to drop it off with John Walker

Thanks
Alan

206AA
1968 Porsche 911 2.4T
Old 12-30-2003, 12:10 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
 
Registered User
 
rs911t's Avatar
 
Join Date: Sep 2002
Location: Leesburg, VA
Posts: 1,206
Garage
All of the diagrams I've seen fail to show this o-ring.
__________________
Greg
1972 911T
TrackVision
Old 12-30-2003, 04:45 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
Registered User
 
Join Date: May 2001
Posts: 7,492
Garage
Beyond the mixture issue, I don't see how you can seal the idle jet holder against leakage of fuel without the O-ring???? It would be just brass against brass. I've mistakenly left the O-ring off of a holder in the past and it leaked!
Old 12-30-2003, 05:12 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
Registered User
 
john walker's workshop's Avatar
 
Join Date: Mar 2001
Location: Marysville Wa.
Posts: 18,456
they'll still seep over time. every carb you see has red seepage marks around the gaskets, jets and plugs.
__________________
https://www.instagram.com/johnwalker8704

8009 103rd pl ne Marysville Wa 98270
206 637 4071
Old 12-30-2003, 05:21 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)
Registered User
 
Join Date: Mar 2003
Location: Seattle, WA
Posts: 176
I installed rubber o-rings around the idle jet holders and replaced the main jets (with 130's, the previous jets were tiny in comparison with no size stamped on them!). The o-rings seemed to have made the mixture easier to set or maybe I have finally developed an ear for it, beats me . . Anyway, after installing the correct main jets, correct idle jets (with o-rings) and oiling the o-rings on the mixture screws. . . My webers are finally tuned and the car purrs. It is really nice to have seamless transistion between the idle and main circuits now, what a difference!. . My 2.4t weber setup is as follows:

Main Jets-130
Idle-.55
Venturi-30
F26 Emulsion Tubers
Air Correction jets-180

This seems to be a winning combination so far. .

Thanks to everyone that replied and to all of those who have contributed to my weber tuning education

--Alan

206AA
1968 911 Targa (2.4T w/webers)i

Old 01-02-2004, 04:39 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 03:17 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2020 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.