Repairing stripped Amal carb threads

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Buzzook
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Location: Kempsey, NSW, Australia

Repairing stripped Amal carb threads

Post by Buzzook »

I'm sure this has been covered endlessly but can't find the threads....

One of our guys has two Amals with stripped banjo threads and has not been able to find helicoils or whatever in the correct thread in Oz.

Anyone got a solution to the 'stripped Amal banjo thread' issue?
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Still trying
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Re: Repairing stripped Amal carb threads

Post by Still trying »

Hi I had the same problem recently. To find helicoils in the same thread pattern is like finding rocking horse shit - impossible. I bought a 16x2 metric helicoil kit and a metric banjo the same size (had to trim the length of the metric banjo to stay clear of the jets and the Loctite insert as well cause they were to long) and it solved my problem. Just follow the instructions accurately and you should not have a problem. The cheapest helicoil kit I could find was on ebay about a $100 Aus I think I paid for it. Before I used the helicoil I tried various fuel resistant sealers and none were successful. Just go metric and your problem can be solved. I informed John (SOS) via email of my problem looking for a replacement Twin Jet Amal then he closed for the holidays I think and by the time he got back to me I told him what I had done to fix it and he congratulated me on my efforts which was very nice of him ( Don't let him find out it was a metric solution :lol:) Anyway the Helicoil kit cost a bit but there is enough gear in it to fix 20 carbs.
Cheers Bob
Still trying
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Re: Repairing stripped Amal carb threads

Post by Still trying »

Sorry slight exaggeration just went out to the shed and had a look, there are enough inserts to repair 12 carbs. If your going to search for it on ebay the brand is Zuess Industrial Tools - Thread repair kit
Cheers Bob
Still trying
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Re: Repairing stripped Amal carb threads

Post by Still trying »

OMG just read my first post and saw that I called the helicoil insert a Loctite insert whoops to many ales sorry :lol: you get that when you hang around seagulls to much.
Cheers Bob
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Oyster 49
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Re: Repairing stripped Amal carb threads

Post by Oyster 49 »

John does offer an exchange service for repaired Amal carb bodies. You are right it's an oddball thread.
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Buzzook
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Re: Repairing stripped Amal carb threads

Post by Buzzook »

So what does JOhn repair them with? Can he source Imperial helicoils?
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Charles uk
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Re: Repairing stripped Amal carb threads

Post by Charles uk »

John's repair utilises a stainless steel threaded insert, threaded on the i.d. with the Villiers banjo bolt thread, so your existing banjo bolt is re used,
& on the o.d. with a much coarser thread, the throttle body is cleaned & stripped bare, machined out to tapping size, then tapped to the coarse o.d. thread size, the stainless is then screwed & glued into the base of the throttle slide body to the full depth of the thread, leaving the excess length of the insert protruding, which is then machined to give a clean fuel proof gasket face & to remove any excess length of stainless, to avoid any change in fueling due to the changed height of the float chamber a thicker fibre washer is supplied with the returned throttle body.

Some throttle bodies are so corroded that they are unrepairable, so check first they haven't gone past the point of no return!
Make it idiot proof and someone will make a better idiot.
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Buzzook
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Re: Repairing stripped Amal carb threads

Post by Buzzook »

That sounds like the Deluxe method of fixing the problem, but clearly does the job and lasts.

I'll pass that on.
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Oyster 49
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Re: Repairing stripped Amal carb threads

Post by Oyster 49 »

I think that is pretty much the only way. I have a carb that has previously been repaired in a similar way with a brass bush. You could just bond the bush in place with epoxy rather than threading it I suppose.
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