Weber 34ICH setup help

Yatesy

Yatesy

Member
Hello,

I’ve got a new Weber 34ICH which bolted on as a straight fit to the old manifold and I would love some help from anyone who has this installed or has seen one installed how the throttle linkage would work.
Obviously it is slightly different to the ZENITH 34IV that came off it but it’s very confusing.
When I attach the throttle return spring to the rocker cover “hook” it holds the throttle butterfly wide open so obviously that isn’t right as it should return it closed. That’s in photo with A to B marked.
C, do I need to hook up power to the throttle cut out sender or can this be left as is.
D, is this the choke setup?

Photos with drawings attached.

Absolutely any help, photos, suggestions are greatly appreciated.

Cheers,
AdamFC3CD2F3-C0BD-4A2C-AA3F-72C797A57BAD.jpeg5B97F692-882F-4F4F-86AA-6FC388465AFB.jpegE1EF6985-35D4-437A-AD3A-26C973314DFC.jpegDEACFA3D-B16B-42E3-BE8C-FB25C1E569BE.jpeg
 
Oh and I’ve had a real hunt through the forum already and unfortunately I can’t see the photos in relation to this Carb as that photobucket message is there instead of the photos.
 
I just fitted Su carb so haven’t got a clue sorry. Panky may know. Have you tried Martin, he’s open on a Sunday so he may help if you give him a bell?
 
Bugger! Thanks Martin.
So my next question is I was under the impression that the Weber 34ICH was the correct carb based on research here. Are there variants to this carb that actually work in our set ups?
 
Sorry ignore what I said, still had sleep in my eyes!! It's just the throttle lever that is wrong, yours comes off the bottom and it needs to come off the top, hence the spring opening the throttle instead of closing it.
 
Martin, thank you very much for the photos.
Those will give me a starting point to see if it can be modified/adjusted.

The auto electric choke is obviously completely wrong now that I know what that is. I’ll need the manual choke setup and I have no idea if the electric one can be removed and a manual one put in its place.

Did not realise there were many variants of the 34ICH and now looking online I am kicking myself.



martin maltas said:
Sorry ignore what I said, still had sleep in my eyes!! It's just the throttle lever that is wrong, yours comes off the bottom and it needs to come off the top, hence the spring opening the throttle instead of closing it.
Click to expand...
 
I think 'C' in your picture is a fuel cut off valve solenoid to prevent the possibility of running on after switching off the engine.
 
Ok thank you getting my head around it now.
My last discovery is the carb I have has a 25mm Venturi and the manual choke version I have found online that is identical to yours in photos has a 29mm Venturi.
Do you know what the original size of the Venturi was in the Zenith 34IV? Probably don’t want to downsize the Venturi by accident but then that’s more velocity = more fuel/air...
 
Yes thanks, that’s right that’s exactly what is. Thanks for reminding me. I’m slowly getting my head around this Weber and it’s a bit tricky since my original Zenith is not currently at home so can not compare setups at the moment.
dodgeram said:
I think 'C' in your picture is a fuel cut off valve solenoid to prevent the possibility of running on after switching off the engine.
Click to expand...
 
Yep looks like an an anti run-on valve, probably just needs a ignition live connection but check first. I've got a couple of old Zeniths so I'll check the venturi size in a bit, but a smaller venturi will restrict the engine even more than the Zenith.
 
Just measured the 34IV and the venturi is 34mm so a bit (a lot) bigger than your Weber.
 
Yatesy said:
the carb I have has a 25mm Venturi and the manual choke version I have found online that is identical to yours in photos has a 29mm Venturi
Click to expand...

The 29mm venturi version seems popular with the Land Rover enthusiasts. I have a lightly used 27mm version waiting to go on my Commer, hoping that's not too small...
 
Thanks everyone for your help.
After a bit of research around the net I have the wrong carb as Martin pointed out.
My 25mm Venturi choke carb is for engines rated 1000cc - 1300cc.

The carb I need for the 1725cc engine is the 27mm Venturi choke 34 ICH carb.
The 29mm seems to be for the 2.2 litre land rovers and Saab’s. A supplier mentioned that would work well but mostly at higher RPM and the 27mm would be a better all round fit especially at mid rpms.
So now I have a useless brand new carb in a box and the 27mm version in the post. A bit of a learners error there..

And the throttle return lever/ball can be switched to the top also like Martin said so the return spring can be hooked onto the original position on the rocker cover.

Thanks again
 
I have fitted a new 34 ich, it runs like sh17 what are the correct jet sizes not only the tick-over and main jet but the others as well.
 
Hi and welcome along :)
According to the manual the correct carb is a 34 IV with the following.

Choke 26mm
Main jet 80
Compensator jet 125
Slow running jet 45
Slow running air bleed 1.4mm
Needle valve 1.5mm
Pump jet 50

If all else fails there is a Webber conversion available that bolts straight on and an SU conversion which is more involved (and expensive) but give even better results.

Hope this helps
 
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