Carb springs.

[66nige]

Has anyone had any issues with the springs on weber 34 ict's not being strong enough? I've temporarily fitted a central spring on the csp bellcrank linkage to the dynamo so it snaps back. Would like something more permanent and pleasing on the eye though What are your experiences and solutions guys?

 

[StuF]

Not sure if the image will come out but you can see my return spring arrangement - returns the throttle back to the idle position no worries and the spring is more than upto the job
I got the small brass bracket at the top from Eurocarb as it was missing when I first bought the carbs - what does your carb look like?

 

[66nige]

Not sure if the image will come out but you can see my return spring arrangement - returns the throttle back to the idle position no worries and the spring is more than upto the job
I got the small brass bracket at the top from Eurocarb as it was missing when I first bought the carbs - what does your carb look like

Pretty similar although mine look a slightly narrower gauge. Set exactly the same but throttle continues with a higher rev when pedal is released

 

[StuF]

Have you checked the actual linkage is moving freely and do you have a buttys bits throttle kit installed?

 

[66nige]

Have you checked the actual linkage is moving freely and do you have a buttys bits throttle kit installed?

Yes mate it's all adjusted and moving freely, buttys linkage new pedal plate and spring......just struggles to return without that extra help. Im thinking of sourcing some heavier carb springs see if that helps.....yours do seem thicker wire though.

 

[StuF]

Yep they have plenty of oomph when returning to the idle position - not had to worry about it sticking so far!

 

[Middleton]

I know it's a bit of an obvious suggestion, but is your accelerator cable too taught?

 

[Moseley]

Or is your throttle cable snagging or not free enough in it's tube?

 

[66nige]

I know it's a bit of an obvious suggestion, but is your accelerator cable too taught?

No it's adjusted nicely just hasnt got that snap back when you take your foot off the gas

 

[66nige]

Or is your throttle cable snagging or not free enough in it's tube?

no, it seems ok......always ran free enough with the old bocar carb too.

 

[Moseley]

Or is your throttle cable snagging or not free enough in it's tube?

no, it seems ok......always ran free enough with the old bocar carb too.

Ultimately there's resistance somewhere, and don't forget that with dual carbs there is more resistance again. Just because it was ok with the single, the move to twins could just be taking it past the point of sticking. It can only be the cable, linkage or carb butterfly, possibly even the pivot points under the pedal. Stronger springs will I'm sure make it work, but then you will be putting more stress on the moving parts as it is a bit of a workaround. Better to find the problem I'd have thought.

 

[Middleton]

This problem is discussed in 'Punnet's Guide to Setting Up Weber 34 ICTs':

http://www.justkampers.com/forum/viewtopic.php?f=15&t=169891" onclick="window.open(this.href);return false;

This is the relevant passage:

"Now the other important thing, Throttle return springs; I don't know who designed these but they are terrible!!! You will note that if you put them on where you are told to they pull the arms UP but not ACROSS to the stop...So you all fit ingenious spring systems (some quite amazing looking) to pull the throttle back to the stop.
Do this instead: Get two stock Solex carb return springs (same as for the Bocar) and fit them into the holes on the throttle arm and on the left carb to the hole on the angled bit of the mounting plate against the fan shroud....There is a hole there strangely if you look at the bottom of that part. On the RH carb there isn’t as it is the other way round (not handed) so you either drill a hole or simply hook the return spring into the angle where the plate changes shape at the top of the mounting section on the carb. Does that make sense? There is a horizontal bit then it changes twice to go vertical to the crossbar linkage...use the first angle. Works a treat and closes off the throttle. The throttle is lovely and soft then and not a pain to keep on the floor. (You may need to bend the accelerator stop tab up to get more throttle but NOT on automatics!!!!) Helper springs which are round and work with the movement are helpful strangely but with the EMPI and Bugpack systems difficult to fit."

Hope that helps!

 

[66nige]

This problem is discussed in 'Punnet's Guide to Setting Up Weber 34 ICTs':

http://www.justkampers.com/forum/viewtopic.php?f=15&t=169891" onclick="window.open(this.href);return false;

This is the relevant passage:

"Now the other important thing, Throttle return springs; I don't know who designed these but they are terrible!!! You will note that if you put them on where you are told to they pull the arms UP but not ACROSS to the stop...So you all fit ingenious spring systems (some quite amazing looking) to pull the throttle back to the stop.
Do this instead: Get two stock Solex carb return springs (same as for the Bocar) and fit them into the holes on the throttle arm and on the left carb to the hole on the angled bit of the mounting plate against the fan shroud....There is a hole there strangely if you look at the bottom of that part. On the RH carb there isn’t as it is the other way round (not handed) so you either drill a hole or simply hook the return spring into the angle where the plate changes shape at the top of the mounting section on the carb. Does that make sense? There is a horizontal bit then it changes twice to go vertical to the crossbar linkage...use the first angle. Works a treat and closes off the throttle. The throttle is lovely and soft then and not a pain to keep on the floor. (You may need to bend the accelerator stop tab up to get more throttle but NOT on automatics!!!!) Helper springs which are round and work with the movement are helpful strangely but with the EMPI and Bugpack systems difficult to fit."

Hope that helps!

thanks for this^^^ i will look into these recommendations

 

[Middleton]

No problem Let me know if it works!