Yay....first issue: Carb float cracked, full of fuel

[Czechsix]

On that 700AP I picked up yesterday, took it out for a little spin and it loses all power, stumbles, and finally chokes itself out on any kind of steep slope or off camber situation. That's always meant carb issues to me in the past, so I gave Jim a holler and me mentioned that the floats in these carbs (32mm Solex single barrel, btw) are notorious for cracking.

He was right on the money, I pulled the top cover off the carb, yanked it off....and the floats are loaded. I've given Leo C. an email for new parts, but in the meantime Jim mentioned it might be possible to use some of the gas tank epoxy to fix the floats.

Anyone ever done this? If so, how'd it turn out?

I'll probably source another one just to be sure, but when I have the time I'll pull the float, drain it (I've already drained both sides - #60 drill works fine right in the solder plug), boil the heck out of them, and then try a new solder plug. I'm pretty decent with fast soldering. Thought I might also make a copper heat sink to wrap around while I solder the plug, just so I don't loosen the seam solder job. I'll just a large electric iron for the job, after cleaning the hell out of the surface and getting a good flux going on it.

But that's in the future, now I'm off to the LAPS for the epoxy...yay.

[heinkeljb]

Depends on how clean you can get the surfaces clean. You really need to try and clean the inside of the cracks as well as just the surface.

So what I have done in the past is to use a thin blade / cutter and cut down a short section of the crack to clean it. Fill the cut / clean section, hopefully getting all the way through. Waiting for it to cure. Doing another small section in the same way until all the cracks are filled. Then tidy things up with fine sandpaper.

Must admit I haven't checked recently on the float I did like that back in the '70's to see if it is still sealed. That was just with 2 part epoxy resin.

John

[Czechsix]

We'll have to see what happens.

I did the usual surface cleaning, scuffing. Then acetone for cleaner, then back into the sun to kick the vapor pressure up. Then another wipe down with acetone, plugged the hole with a little piece of the end of a toothpick, making a wood plug. Then mixed up the resin, layed a coat on, put some fiberglass roving in, then dabbed to get the resin into the matrix. It bubbled a bit for ten seconds or so, as the vapor continued to vent, but I kept working it. Within thirty seconds the resin started to pop, I had the 'glass already saturated, so I just feathered it out. It'll sit for another hour, then I'll reassemble.

Now I'm off to find some silicone tape to do a field fix on the intake boot, which is cracked in multiple places...from the oil bath filter to the element, so it's not a huge deal, but it'd be nice to get it more functional. I live in a dust bowl.

Also, in digging around, had a nice find - the complete tool kit came with the truck, along with the usual swiss warning triangle in a case. That was nice to find! Now I need to find a swiss drivers manual for it.

[AustHaflinger]

I had the same issue with the plastic floats in my Zenith NDIX carb - I used a specialist Devcon product but it failed after a little while - then used good old Q Bond Superglue (has a metal filler) which worked well until I got new ones from Jim.

As a side issue my Haffy came with a 34mm Solex - my previous owner considered thought the 32mm was too small. The proper Zenith NDIX is a much better carb.

Garry

[Czechsix]

I was wondering if that superglue might work, sounds like it might be the ticket.

In any case, the fix is done, no more issues with running like crap on slopes...but now it runs like crap on the flat ROFL. I'll pull the carb and go through the whole fuel system. Wouldn't surprise me if there's some crap in there, and I need to pull the filters anyway.

My old truck is running the weber 32ICS...looks simple, I've looked at the manual and it looks like it's not too much of a pain to deal with. I'll break her down and boil her out, then reassemble and do a tune, we'll see how it goes. I might just go ahead and pull that rotten exhaust out while I'm at it.

[heinkeljb]

Haflinger's have had at least 3 different Carburettors fitted to them over their production run. The Zenith being the last one fitted.
Any of them should be good if the carb is in good condition and set up correctly. People forget that the Grand canyon was made just with running water and the same thing happens in a Carb on a smaller scale, but it can change the way it delivers fuel and air to the point the engine doesn't like it any more!

Another thing to check if you have a dual float system, it that each float weighs the same - the nearer you get the weight the same the better.

John

[Czechsix]

Got a couple of new gasket kits, I'll break down the carb Sunday, if I have time. I did the epoxy fix, bowl level was good for a few days, but the idle circuit is clogged up, pretty obviously, had to run the rpms up to get it to work. Slopes, etc, no problem.....but tried it again yesterday, totally flooded out. Could be crap on the seat too....but I'm betting the epoxy didn't hold.

Sunday, if the epoxy hasn't held, I'll take it off, boil out the floats, and resolder them. I'll need to put a couple of new fuel filters on too, after I blow everything out and rebuild the carb. Maybe I'll do the old standby boil out with some vinegar and water.

[AustHaflinger]

If your floats are metal - definitely resolder - my comments above related to the plastic floats in the Zenith 32 NDIX.

Garry

[Czechsix]

Yep, these are the thin brass(?) plated twin floats. Previously soldered, but over the years the flexing of the floats has cracked the metal for a couple of millimeters on each side of the central hold. I'm pretty sure once I clean them I can get a good joint on them. Might have to make a copper fixture to hold them though - there's a seam where the two halves were soldered together, and I sure don't want to have to resolder that....if I hit it fast enough with a good clean flux it should do it.

If it works....I'll post it up.

[heinkeljb]

If it doesn't work, post it up! I am sure others would be equally interested in seeing what you are trying to do. Even if the proviso is that "This didn't work, don't bother trying this"!

The original "Araldite" epoxy resin was very petrol resistant, I not so sure about all the other variations of 2 part epoxy resins you can now buy. There is an American product which claims to be highly resistant to petrol and various other solvent type fluids. I don't know how well it would stand up to the new "bio-mix" fuels we now have.

If the float's are brass, then soldering is the only way to go. You just need to make sure you use the correct flux and solder. A jig to hold all the bits in the correct position even if the solder joints loosens would mean you could ensure you get enough heat into the joint you are trying to mend.

Plasticine springs to mind as being easy to mould round the shape and to keep things steady.

John

[AustHaflinger]

Before resoldering you need to make sure all the fuel is removed from inside the float. You made to drill a very small hold into the float and leave until all fuel has evaporated - if the hole is small enough it can be simply soldered up but watch the weight of the repair.

Garry

[Czechsix]

I'll definitely sum it up once I get it done.

I've used a 2 part resin on there, mixed in a bit of roving for additional support, but I think it probably didn't work. Either that or the needle has crap on the seat, or the fuel pump is putting out too much pressure. Either way, it's flooding again, needs to come apart. The product I used was a liquid epoxy, designed specifically for fuel tank sealing, but as you mention our new fuels are wonderful solvents and do a number on all sorts of compounds. Carb comes out today, I'll tear it down since I got the new seal kit and assess things.

The floats are brass, but so damned thin that I'm sure I'll need a couple of tries to get it done. Major worry is the seam coming apart, I'll be using at first a large electric iron, if that doesn't work I'll be using an old plumbing iron. Don't really want to get flame near it. Even with the irons, heat transfer will be terrific on this thin sheet (almost a foil), and I was thinking about machining out a chunk of copper, and using that as both a heatsink and jig during the resolder. Might be more than it needs for the job, but then again....do it once, do it right (lol, I already screwed that up). It's not like these floats are easy to find if you need a replacement.

Garry - I usually boil out this sort of stuff, lemon juce and distilled water for a while. Only way I've found to get rid of both the fuel and the varnish. Our fuel is absolute crap over here in California. Pure junk, but it is what it is.

[walderse]

Hello to all,
A couple of years ago, a friend purchased a very nice 1968 Swiss 700AP. In the box of spares that came with the truck two piece molded form fitting case for a replacement float assembly for the stock Weber 32ICS. The manufacture's logo was embossed into the case. Inside was a brand new float assembly made from aluminum and two cylindrical cork pucks. The aluminum rings that encircled the cork rounds were swaged on each edge to afford no movement of the cork. I have never see another set like this but was told that these are available form a supplier in Europe somewhere.
Hope this helps.
Take care.

Jim Molloy
Waldersee Farm
http://www.northwestmogfest.com

[Czechsix]

Hi Jim, now that's very interesting. Personally, if it comes down to it, I can make a new float system for it, I'm pretty sure. That does help, and I might try getting in touch with some of the suppliers to see what they have. What I've been told about the aftermarket floats (like mine might be, according to Goatwerks), is that they have a bad habit of cracking and filling up. The cork idea....that sounds good. The wife drinks enough wine that I have plenty of corks available (just kidding honey....just kidding).

[Czechsix]

Just tore the carb down all the way, had to pull the intake manifold to fix the rot on it, so might as well check to see how the float fix went.

Complete, total, utter failure. Float filled again, so now I'll try to clean it well, drain it all the way, purge it, and solder it. One issue that might or might not be an issue is that the float that's damaged has a smaller volume than the float that's in good shape. The one on the bad side has dings and dents in it....might be an issue, or not. Can't hurt to try to solder it, not like it's going to be any more damaged, lol.

I think I'll probably be looking for another float, and maybe another carb. The throttle shaft in this one is a tad loose. I've seen worse, but I've seen better too. Or maybe I'll try bushing it.

At least it's fairly clean now, I threw all the parts in an ultrasonic cleaner for a while. Lots of grunge came out.

[Czechsix]

OK, sourced another carb that has a perfect float, so that's going in. The current float that's in there also has a smaller displacement - the half of the float that's cracked has been pushed in. What I might do with it, since it's basically messed up right now, is drill the center hole out again, and try to run some gas pressure in there (just using a compressor...up to 125psi or so) and see if that bumps it out. If that doesn't do it I'll try to calculate ice expansion, figure the total volume of the correct float, drop the calculated volume of water in there, and freeze it, hoping the ice bumps the float side out.

I guess I could post pics, if anyone's interested. I'll start another thread on the manifold brazing I'm doing, to repair the rust holes. So far I've done one manifold, came out fine, next is a much worse case that'll need sleeving and brazing.

[heinkeljb]

I think that would be an interesting thing to watch unfolding either as a video if using the air compressor or slide shop pictures if using the ice method.

I have got to do the same sort of brazing / welding on the exhaust sytem on Lurch as it appears both heat exchangers have blown.

John

[Czechsix]

I can take a video of the air pressure experiment. I'm thinking it's probably not going to be enough, but then again those floats are really thin material...almost a foil.

The brazing I did on the manifold was on those heat exchanger tubes and the intake manifold tubing itself - one right at the driver side connection, and one braze to fill in a really poorly done weld repair, looked like MIG where someone had no clue about heat control. Big globs of cold joint, blown through hole, etc.

The other manifold I have to repair will have to get a 14 gauge or so sister plate over the rotted area, that one is the original that came on the truck, hole is somewhere around 2cm long by 0.5cm wide...huge. Blowing right into the engine compartment...can't have been a good thing. I'll have to pound out a contour out of some sheet I've got...ball peen hammer time! Yay!

[Goatwerks]

I have a spare float and intake sitting here if you need them.