Carb trumpets

[danbuoy1]

Mostly stripped, had problem getting accelerator pump out and bent the hook, once I saw how it worked fashioned one from an old tent peg(!) to pull the valve out - looks ok.

You mentioned supporting the weak spindle, I've a couple of old disks off my Strom rebuild, presumably modify and screw in place while tapping out shaft? Is it worth trying to pull the shaft out instead? I reckon it will be tight, any advice welcomed.

Cheers

Paul

[Craven]

Although the tap through method removes the spring retaining cover, the Weber description, outer cover with 2 holes, it may well be worth removing this by prising it out first this will allow to remove the spring and dust cover so some penetrating fluid can reach the bearing. As your carbs are corroded you will inevitably increase the light tap to more serious blows, these spindles are particularly weak where the fixing hole are countersunk in the shaft and will bend into the slot so pack this area, I don’t think there is any advantage in pulling the shaft as the force required is the same.

[danbuoy1]

Cheers Craven. I've a couple of old strom butterflies I could cut and fit - guess its wise to screw them in as well.

I have tried getting the end cap out but they're not budging, I'll try a bit more heat.

I wondered on pulling to reduce the chance of the spindle bulging if hammered, or possibly a combination of the two?

I just want to get it stripped so I can fully assess.

Cheers

Paul

[2cams70]

When you are tapping out the shafts with a PLASTIC hammer just hold the carburettor firmly in your left hand whilst tapping it with your right. Do not rest it on something hard as this will transfer a lot more force to the shaft and body and risk damaging them. If really stubborn use some heat. Not too much as you only want to raise the temperature to a bit over 100 degrees C. Aluminium expands at roughly 3 times the rate of steel under the action of heat. You’ll need to get yourself some heat proof gloves in that case. If you have steel shafts they will be much harder to bend and I would not worry too much about packing them. This is where the “feel” part that I mentioned earlier comes into play!

[danbuoy1]

Cheers 2cams70, I'll follow your advice. TBH I can't remember if its steel or brass - I think its brass tho, I'll check it tomorrow. Thats a lot hotter than I have been heating it (with a paint stripper gun) as can still handle it so maybe I need to turn it up a bit. I need to find my plastic hammer, till now I've been using a rubber mallet, probably still too heavy. Have been using plusgas and seems to be working better than others!

Cheers

Paul

[Craven]

[2cams70]

I need to find my plastic hammer, till now I've been using a rubber mallet

Yes you need to uses a plastic hammer not a rubber one. That's why I have it in capitals. A hard plastic hammer strikes the right balance between not causing any damage whilst still transferring sufficient force. A rubber mallet is too soft.

[danbuoy1]

Thanks Craven.

Well I had another go at it (its steel BTW) and managed to get one of the end caps off and could see how it worked. The other end wouldn't budge so maybe unnaproved method - I lightly screwed a self tapper into one of the cap holes to see if I could prise out, levered gently against the shaft end and suprised it started to push bearing out opposite end! Pulling shaft with pliers and gently tapping body the shaft and bearing came out ok.

Can't shift the other end tho but now I've inner access I'll try to drift it out with something more solid - suprisingly the old shaft from a Stromberg is exactly same diameter, will try again tomorrow.

Thanks for everyones help, much better understanding of how it all works.

Cheers

Paul

[2cams70]

I lightly screwed a self tapper into one of the cap holes to see if I could prise out, levered gently against the shaft end and suprised it started to push bearing out opposite end!

One of the reasons why I suggested not to attempt to remove the cap separately is because it is brass and easy to damage. It's only a light press fit in the bearing bore and once the bearing behind starts moving it will start moving too quite easily once contacted by the bearing from the inside. Being made of brass means it won't be corroded in place unlike the bearings which may be. The replacement caps you get these days are plated steel and not brass. Being made of steel these are subject to corrosion and are of much lesser quality than the original caps. Once the original brass caps are removed you can safely reuse them provided you haven't damaged them by needlessly poking and trying to lever them out. Extract from the original Weber manual describing correct procedure for throttle shaft removal and replacement is attached for your reference.

[danbuoy1]

Good help thanks, interesting they say assemble one bearing on shaft, other in housing - maybe thats why mine has come apart like that. I was more wary in bending the shaft so happy its come out the way it has.Removing dust cover sounds so easy Hopefully can drift other side out complete with dust cap.

Cheers

Paul

[danbuoy1]

Just to add - I borrowed an Ultrasonic cleaner off a friend, we had tried this years before with a noddy jewellery cleaner without success. Wow - did this one work, impressed! Great for cleaning those hidden parts, jets etc came up a treat.

I'll get one myself.

Cheers

Paul

[2cams70]

Just to add - I borrowed an Ultrasonic cleaner off a friend, we had tried this years before with a noddy jewellery cleaner without success. Wow - did this one work, impressed! Great for cleaning those hidden parts, jets etc came up a treat.

I'll get one myself.

Cheers

Paul

Yes they are great. DO NOT however throw aluminium parts into the cleaner to get rid of any remaining grit after they have been hydro blasted or you will get staining. It may be OK if you just have water in the tank but a cleaning solution (even aluminium safe) may give you problems. Speaking from experience here.

Don't forget to check those lower galleries too. The ultrasonic cleaner will not work with these. If blocked they must be manually cleaned.

[vstibbard]

What cleaning fluid did you use?

[2cams70]

What cleaning fluid did you use?

I used a cleaner that was specifically for carburettors and specifically for ultrasonic tanks. It works fine for a first clean and it also works fine if the parts are 100% submerged and there's no trapped air pockets under the carb whilst submerged.

If parts have air pockets around them you will get a light brown staining on aluminium just at the interface between exposure to air and the liquid. It can't be easily removed unless the parts are blasted again!

[danbuoy1]

The one I borrowed was a 5l capacity, an ebay import I guess. the liquid (again "borrowed") was by Allelndale Ultrasonics, not sure what it contains. It was like watching pirranah's nibbling away! Not promoting it but after a dismall attempt cleaning diesel injectors in a small ultrasonic I wasn't expecting much but pleasantly suprised.

I was going to glass bead outsides then ultrasonic clean - I was hoping this would clean the passages inside carb as presumably only gunge from sediment? Didn't want to remove sealing plugs if possible. How about squirting cleaner down the passages?

Cheers

Paul