Burman BA Cable Adjuster Lug Repair

[paul.ptak]

I'm sure someone has had to deal with this before.

Before I attempt to repair, anyone care to advise on the best way to do it?

My first thought is to completely fill the open area by TIG, then machine and shape the lug, drill, tap, and cut the slot.

Also can someone confirm the threads for the cable adjuster are 3/8x26 BSC?

Thanks.

Paul

[Ian.Taylor]

I had a similar situation on my Q box on both the adjuster lug and the clutch arm lug.
I used Lumiweld to build it up then I used a grinder to get the build up off then a dremel to get the shape along with files.
not sure what your thread size should be.

[paul.jameson]

Thread size is indeed 3/8 x 26 cycle thread.

[stuart.wilby]

Looking at this repair, it is what is know as a free end, it should present no expansion or contraction issues during the heating process, therefore it could be done well using a MIG Welder, with a Teflon liner fitted for the wire to travel down, this will present you with minimal friction which is a plus using the 0.8mm aluminium wire. The gun must be connected to the positive pole of the welding machine, that's + for the beginners. You must use pure argon 99.9% pure, and don't be shy with this, it needs good coverage a nice flow, (not too much or it pulls in the atmosphere acting as a Venturi). Clean up the complete area inside and outside the hole using a stainless steel wire brush and or abrasive wheels to remove the oxide layer which is always present, this must be done immediately before welding, preheat is recommended, but not essential with a free end, take the chill off. Practice on a bit of scrap, go through the whole sequence of the procedure above, cleaning etc, you will be amazed of the simplicity if you set your stall out and work logically, fill in the whole of the missing lug and remachine, good luck.
PS:I use a Clark 135 MIG set with exceptional results every time, I always do a dry practice run to set up the machine parameters and take the chill off with a blow lamp.

[simon.holyfield]

Great advice there Stuart, thanks for that - I have one of these to do as well.

[stuart.wilby]

If it helps, my MIG machine is dedicated to welding aluminium, the prep work always takes time, I have a lug to repair on a BA casing which was rescued from eBay for £25, I don't need the casing but it is in the spares pool now not the scrapyard.

My 48 square 4 came to life in December for the 1st time since I bought it as a project 7 years ago, some teething problems with the solex carburettor are now resolved, I am working towards a fix for sealing the butterfly shaft, probably a Teflon bearing insert either side as they do with the VW carbs, I have some spare old carb bodies to practice on.

[chris.shearwood]

some teething problems with the solex carburettor are now resolved, I am working towards a fix for sealing the butterfly shaft,

Hi Stuart,
To seal the Solex butterfly shaft you might want to consider the method I used on my 46 Sq4: machine an appropriate sized groove on both ends of the shaft and fit a couple of Viton o-rings. I've put a couple of thousand miles on the bike since the modification with no problems in that department so far.
Regards, Chris

[Eero.Korhonen]

Hello,
We did the same thing back in 80's to old car carburettors, which used to leak and suck air from shaft.
I did have Vauxhall Viva HC in those days.
Br, Eero

[stuart.wilby]

Thanks for the fix Chris, it sounds like an easier solution than the Teflon bush I'll give it a go with a spare shaft I have lurking around.
Another problem I have encountered is the banjo bolt, the one I had with the float chamber top had destroyed the 1st 2 threads in the alloy casting fuel inlet, it wasn't long enough to get at all the threads after all the fibre washers and bi-starter bracket were racked up on it, it had been stripped by over enthusiastic tightening of the banjo by it's previous owner, however, This has been fixed by making a new brass banjo bolt with a 5/16" longer threaded portion to get at the good threads at the back of the fuel inlet port, Job done. I believe this is a common issue where the banjo could do with a few more threads to accomodate the bi-starter and banjo fibre washers. Also a safety issue worth checking on most solex carburettors and is probably the reason for most leak issues around this connection.

[paul.ptak]

Thought I'd share a photo of the repair.