Weber ict issues

[jammac]

Upgraded my single port 1600 to 1641 with twin weber 34s.

It didn't explode on first attempt but does run like utter ***** lots of popping and seems to struggle or occasionally stall when revving up gradually. If revving hard it seems ok until driving where it lacks all power. Just driving 50m up the road to test I'm struggling not to stall.

I jetted the carbs as per recommendations for 1641 on here I can't remember what they were off my head. But do these issues sound common to incorrect jetted carbs?

Also I fitted a elec fuel pump with a filter king regulator set up to 3psi. I played with the pressure range on this also from 2-4psi and it made no difference.

I've got a balance tube and breather pipe connected to one of the filters.

I followed the guide on here to set them up and even used a synchroniser tool to balance the airflow

HELP!

 

[rlepecha]

Checked the plugs? Idle jet might be blocked.

 

[gas1man]

Sounds really dumb but have you got the correct firing order?

J & P

 

[Stevec]

I fitted a set of 34's on and it ran like **** until I worked out there were air gaps from the manifold. You have to fit the manifolds on first separately then install the carbs after, fitting them together it's too tight against the fan housing.

 

[jammac]

Plugs are fine, firing order is correct. I fitted the manifolds first aswell. I'll check for leaks and then remove again and see if there's a blockage. I'll post up my current jet sizing in abit. See what I should tinker with first

 

[gvee]

Check/reset timing.
When idling spray some carb cleaner about and listen for changes in engine note. This will highlight any air leaks that might be present.

 

[jammac]

heres the list of the jets ive got fitted. i took this list directly from someone elses post off here for a 1641.

mines a single port though

140 main jets
55 idle
160 air corrector
55 pump jet

f6 emulsion tube rings a bell but i havent got this written down so dont know without disassembly.

ill check the timeing and spray the carb cleaner also.

 

[john the horse]

What dizzy ?

 

[jammac]

009

 

[john the horse]

There's ya answer

 

[jammac]

Lol I knew you were gonna say that! Vzi says the same thing.

 

[jammac]

Blimey I just changed the HT leads and it's made a massive differance to the popping and coughing. but the power still drops off to nothing when you push the throttle in slowly.
I'm gonna get a new dizzy how much vac hose will I need? And am I right in saying it connects to the little tube that pokes out the base if the carb. (This is currently blocked off )

 

[Stevec]

It will connecting up to both carbs, about 1.5m your need plus a T joint.

 

[Bay-low71]

Don't be to hasty changing lots of things at once bud. I run a 009 dizzy with my 34 ICT's and it runs fine.

I had a manufacturing fault with mine and needed drilling due to the bowl on one of the carbs didn't have a flow path for the petrol to reach the pump and through main jet. It ticked over fine.

Luckily this was spotted prior to engine going in so could physically see that no fuel was entering the carb on increase of revs. Hope you get it sorted!!

 

[jammac]

Update: new coil and vacuum advance dizzy. All properly timed up (it was miles out). Now starts a lot easier but same issue.

Pump the throttle hard and it sounds sweet and has power but build up gradually as if your pulling away from a junction the revs just drop off and it stalls unless your quick off the throttle to allow it to idle again.

I guess it's the jets? Which ones should I go for first and what size? I posted what's currently fitted previously.

I've got no mot so can't take it anywhere to be setup

Cheers


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[jammac]

Oh and it's back firing through the carbs when opening the throttle slowly


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[privatejobs]

mixture sounds to weak give it a run check colour of plugs nice brown ok white too weak

 

[K@rlos]

There's ya answer

Genuine 009's are good bits of kit. Had 1 on a 1600, got 1 on my race motor and fitted several others to various vw's. Without issue.

 

[Jimbly]

I'm with Bay-Low - I've got twin 34s and a 0009 and it pulls like a train while driving perfectly.

Spitting back through the carbs tends too suggest a lean mixture - either an air leak or jets too small.

I had the same problem and replacing the inlet gaskets (crush rings) solved it nicely. Tried the often-recommended cardboard option and that was worse.

I also cannot recommend a good rolling road set-up highly enough though. I appreciate you don't have an MOT but would suggest as soon as you can, get it on the rollers.