Thought I’d share a picture of my front carb body and the starting carb as well (XK120). The banjo bolt that secured the bottom of the starting carb sheared off. Same with the bolt on the bottom of the front main carb body/ arm to the starting carb. The starting carb looks too fragile to try and set up on my mill in order to bore out the broken bolt bit so I’ll source another. The main carb body looks like I can set up easily enough. Hopefully with a properly centered end mill plunge cuts will be enough to remove whats left. Fortunately I have a 7/16 BSF tap so that should help – though it is a blind hole.
I’m nearing the mechanical end of reviving a car that sat for 30+ years in not always ideal conditions so, I’ve come to expect still hidden surprises like this.
A , I would heat up with a hot air gun and use a easy out , B, I would find a bolt to slide up inside , tighten up in vice , and apply heat and turn in vice , half the fun is trying to fix things right
I had similar problems. I sent my carbs off to be reconditioned. They broke one bolt and I told them not to break anymore or return them. They returned them not done. Ultrasonic in hot parafin (kerosene) and careful heat got them all undone.
Okay, I’ll keep you guys posted on my progress. For the life of me, I still think these are wayyyy beyond any help from a good soaking – but I’ll consider it.
Wigs, I was told in the past that equal measures acetone and ATF is the magic recipe. You have better luck with diesel?
Ok I will own up, I put an oxy acetylene torch directly on the steel bolt for a few seconds, then immediately dunked in parafin , several times.A risky last chance method but it worked for me
I use an old 5 litre rice cooker with degreaser in it. It heats up the degreaser and I can soak items in it. There is no direct element so it is safer than naked flames or getting caught using the Bosses best pots.
Here is the Kroil data sheet describing chemical composition. The primary ingredients are low vapor pressure aliphatic hydrocarbon and severely hydrotreated petroleum distillates. In varying proportions these types of chemicals are found in diesel, WD-40, other petroleum products. One benefit of such solvents is low surface tension allowing the liquid to get into small spaces.
Last year I bought a kit for removing broken bolts, not a big deal EXCEPT the set of EZ Outs included a set of high quality Left Handed twist drills. The broken off bolts I was trying to remove (Mopar head bolts) came out while I was drilling them with the left handed drills drilling in the unscrewing direction.!
Mike Moore
Propane torch, liquid wrench, propane torch, liquid wrench, etc. usually takes several heating and cooling cycles to work it loose.
EZ Outs worked great for me with one heating of the propane torch on some broken grease fittings in brass Mark V saloon door hinges.
In the end I skipped all the penetrating oil/ torch stuff and went with machining them out. I’m fortunate to already have an older, heavy vertical mill but as others may not, there’s no reason why the same results can’t be closely achieved with a decent drill press such as a better Delta or Rockwell – assuming the correct taps (in my case 3/8 BSP and 7/16 BSF) are on hand. End mills (or drills) just large enough so that the old threads aren’t exposed were used followed by the taps. At this point there’s so little of the old bolts left that the the taps are just chasing out a little rusty helicoil of wire while following the path of the old thread pitch.
As a side note, I’d forgotten how great Easy-Off oven cleaner is when it comes to cleaning decades of varnish, carbon and clay-like grease off the carb bodies – in minutes. Very satisfying to watch it bubble away. That stuff must have been flying off the shelves when it first came out.
The two threaded holes on the left were the ones that were problematic.
