Author Topic: carb refurb? (Read 2299 times)

Chris Lakin · « **on:** December 27, 2005, 09:25:04 PM »

i have an old 30dgf weber carb, i think its in better nick than the one i have in car. I've never properly refurbed a carb before, ihave put new bits in from a carb kit, but how do i realy go to town with it and get it like new?

would love any advice

regards

Chris

Lewey · « **Reply #1 on:** December 28, 2005, 07:17:12 AM »

I think you have already done a lot that can be reasonably expected.

Obviously make sure you have dismantled the carb completely and cleaned all parts with petrol and compresed air. Check the jets (bits you screw out inside the carb) for damage or even scoring. Check all the butterflies (read flaps) and seals for damage. Make sure all the levers operate smoothly and their effect on the buttterflies is solid. They may need tightening or new washers, etc. WD40 will ensure a silky smooth action.

After that, really it is all about setup. There is rather good instructions on this in the 126 workshop manual (page 51 on) which I won't re-iterate.

A good tip not in the manual however is to spray some WD40 round the base of the carb when on the manifold ready to go. It will bubble up if there are any air leaksbetwen the carb and the manifold, which will compromise your mixture and make the engine unpredictable and unstable. It can be either the carb being warped or the manifold not flat. Something I've noticed as a problem on the 126s I've seen anyway.

Assuming your engine is otherwise sound, you'll be happy with the results I should think. The carb is the key to your engine being nice to you.

ChrisRLewis · « **Reply #2 on:** December 28, 2005, 10:40:35 AM »

Check for worn throttle spindles which can cause fluctuating mixture levels.
Very often on old carbs the galleries get clogged due to water in the fuel and causing corrosion.
I think the carb reconditioners, ultra sonic the carbs to clean them? Also worth giving all jets and galleries a blow with the air line, but watch incase you damage any diaphragms etc

Chris Lakin · « **Reply #3 on:** December 28, 2005, 11:20:06 PM »

thanks for that guys, its just i've got my MOT coming up this week, last year its emmisions where terrible!!! so worried again, however since then ive swaped the carb from a polish one to the weber, but i have another weber to go on if need be. I've also put a new fuel pump on (last one was letting fuel run down into the sump) so i dont know if that will help? i know fuel pressure can affect emmisions.

Chris you are right i saw a magazine article, recently, they were cleaning some dellorto's up, then ultrasonicly cleaned them, amazing how they came up.

regards

Chris

Pete126 · « **Reply #4 on:** December 29, 2005, 12:36:55 AM »

Hi 126ers
what i have found to be very effective is to boil the carb in water, clean outside of carb with carb cleaner the aerosol type with the extension tube and small paint brush.
dismantle the carb acc' pump, pneumatic diaphram, float, main jets, emulsion tubes and idle jet. leave the idle adjustment screw, put the carb body & top in an old pan fill with cold water and place on stove bring to the boil and boil for 10 mins you will see oil and bits start to float on the top of the water, after 10 mins scim of the bits and tip the water out, take out of pan----don't burn yourself-----turn upside down and let dry. just to be sure spray carb cleaner down the airways, emulsion tubes, main jets, (where you have taken the jets out) clean the main jets then re-assemble the carb, screw the idle screw in gently till it stops and back off 3 full turns, oil the butterfly shaft inside and out, do the same on the choke shaft and the acc' pump pivot, when its back on the car, start engine and run upto temp adjust the idle screw, screw in until the engine hunts then screw out till it runs even, and thats all there is too it.

Chris Lakin · « **Reply #5 on:** December 29, 2005, 01:05:10 AM »

wow thanks Pedro!!!

i will follow exactly what you have said to do, is it ok to boil it? will it not cause warping/disstorion at all?

thanks again

Chris

Pete126 · « **Reply #6 on:** December 29, 2005, 10:47:11 AM »

Quote from: "Chris Lakin"

wow thanks Pedro!!!

i will follow exactly what you have said to do, is it ok to boil it? will it not cause warping/disstorion at all?

thanks again

Chris

Hi Chris, never had a problem with warping, but start with cold water and bring to the boil. i have used this method on twin 40 webers and twin chokes in the past with excellent results.