Weber carb jetting

Post any technical questions, FAQs or tutorials in this section
Post Reply
getafix
Posts: 20
Joined: Fri 29 Dec 2017, 22:02
Location: Krugersdorp

Weber carb jetting

Post by getafix » Thu 11 Jan 2018, 20:51

Need help with 38 weber jetting on my Sierra. Did some work on the motor after 700k kms - RJ cam, bigger valves, unleaded. Can't seem to get the jetting right - fiddling is driving me insane. Sluggish below 2500 rpm = bigger idle jets? Runs out of breadth at 4500 rpm. Idle jets current 55s, mains 137 air 180 - rest is what it was at assembly time. Any suggestions?

'Normal' driving not too bad ... but every once in a while hooligan mode kicks in and it is WOT ... :roll:

Any suggestions will be most welcome.
I'm not a complete idiot, some parts are missing 8O
Ford Sierra V6
AC Cobra V8

bmwmaniac
Posts: 285
Joined: Fri 05 Jun 2015, 21:02
Location: strand

Re: Weber carb jetting

Post by bmwmaniac » Thu 11 Jan 2018, 21:10

get modern technology on your side. fit a wideband lambda probe and guage.
"If you park your car, walk away and don't look back, you're driving the wrong car"
Image

User avatar
BIGSIX
Posts: 392
Joined: Thu 06 May 2010, 14:45
Location: Wilde Weste - Gauteng

Re: Weber carb jetting

Post by BIGSIX » Fri 12 Jan 2018, 07:50

Hi Getafix,

I am running 145 mains and 210 air with 55 Idle and a 55 spray.

just check what spray jet you have and that's the one that sprays through on both sides.

also check your lifter clearances as this can take out some power if not right.

Let me know if you get it right as mine is not 100% yet!
Old Ford's don't Die, they just go Faster!
Hi, my name is Johan and I am a V-addict!

'97 Suzuki TL1000S - V2(SOLD)
'76 Ford Cortina XLE Bigsix 3.0 - V6
'90 Ford Sapphire 3.0 GLX - V6
'97 Mazda MX6 2.5i - V6
'96 Ford Courier D\C 350 16v - V8

User avatar
RASSIE
Posts: 6353
Joined: Tue 11 Sep 2007, 13:17
Location: Amanzimtoti, S.A.
Contact:

Re: Weber carb jetting

Post by RASSIE » Fri 12 Jan 2018, 07:52

Mains 145 and air jets 185 and she will run super fast!!
Rassie.
http://www.rassiesauto.co.za/
“Cowboys do not ride donkeys”
“I will die driving a V8”

User avatar
BIGSIX
Posts: 392
Joined: Thu 06 May 2010, 14:45
Location: Wilde Weste - Gauteng

Re: Weber carb jetting

Post by BIGSIX » Fri 12 Jan 2018, 11:33

I will try that this weekend as well.

Thanks Rassie!
Old Ford's don't Die, they just go Faster!
Hi, my name is Johan and I am a V-addict!

'97 Suzuki TL1000S - V2(SOLD)
'76 Ford Cortina XLE Bigsix 3.0 - V6
'90 Ford Sapphire 3.0 GLX - V6
'97 Mazda MX6 2.5i - V6
'96 Ford Courier D\C 350 16v - V8

User avatar
BIGSIX
Posts: 392
Joined: Thu 06 May 2010, 14:45
Location: Wilde Weste - Gauteng

Re: Weber carb jetting

Post by BIGSIX » Mon 15 Jan 2018, 13:02

Tried the 185 airs the weekend and not as good performance as the 210 airs. Might be because we are a bit higher up than you Rassie?

Switched my carb settings to 142 Mains 210 Air with a 70 Spray. Works well for me not sure if it might work on another motor or carb.

Just my 2c!
Old Ford's don't Die, they just go Faster!
Hi, my name is Johan and I am a V-addict!

'97 Suzuki TL1000S - V2(SOLD)
'76 Ford Cortina XLE Bigsix 3.0 - V6
'90 Ford Sapphire 3.0 GLX - V6
'97 Mazda MX6 2.5i - V6
'96 Ford Courier D\C 350 16v - V8

getafix
Posts: 20
Joined: Fri 29 Dec 2017, 22:02
Location: Krugersdorp

Re: Weber carb jetting

Post by getafix » Mon 15 Jan 2018, 14:07

Thanx Rassie,

Will try this very soon. Carb City the only place to get jets and only Monday thru Friday. :(
I'm not a complete idiot, some parts are missing 8O
Ford Sierra V6
AC Cobra V8

getafix
Posts: 20
Joined: Fri 29 Dec 2017, 22:02
Location: Krugersdorp

Re: Weber carb jetting

Post by getafix » Mon 22 Jan 2018, 19:50

Did the jetting 145 mains - 210 air. Top end much better. Still got a bit of 'hoes en proes' from standstill - comes alive at about 2500RPM - then it is 'hou vas!!!'

:)
I'm not a complete idiot, some parts are missing 8O
Ford Sierra V6
AC Cobra V8

Post Reply

Social Media

     

Who is online

Users browsing this forum: No registered users and 2 guests