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TR2/3/3A SU H6 Carb Conundrum - Stuck mixture adjusting nut

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Colin-TR3

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I just cleaned my SU H6 carbs as the car hadn't run in a few years and there was some gunk in there from the ethanol in the fuel. Keep in mind that when i say it ran a few years ago, that was just a few times after restoration to get it onto and off a trailer, so it was never tuned properly for everyday running. Putting it back together i noticed that the mixture adjusting screw is screwed all the way to the top of the lower jet bearing and will not back off. I have tried soaking it break free overnight - no success. I tried screwing the whole jet assembly back into the carb body and then unscrewing it then - no success. No matter what i do, when i turn the nut, the lower jet bearing turns as well. To complicate matters, i need to get one of the assemblies apart and see what is wrong in there because it is just jumping fuel when i add fuel to the float bowl. And i mean a steady stream, not a drip here or there. I would rather not try to force something into the jet bearing as it is brass and will likely deform with anything strong enough to hold it in place. Is there perhaps something else i could try to separate these two items? Thanks.
 
It sounds like it needs to come off and go to the bench. On the bench you will be able to see better what is happening and use the correct tools to fix it.
 
Unfortunately i have already done that, as far as taking it out and looking at it. They way it is put together does not allow for tools to fix this as far as i can tell without damaging it. See attached.

The jet bearing is completely surrounded by the mixture nut, spring, and sealing nut. I don't know how i would hold it secure to remove the mixture nut from it.
 

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If you have a small bearing extractor you could clamp on the steel nut and apply pressure to the brass jet bearing in the centre by tightening the screwdown of the extractor to hold the jet bearing tight in the nut. You might need to put a small washer in the end of the inner brass piece to protect it from the clamp screwdown. This would allow you to then undo the nut.
 
Cut a piece of wood and shave it down to fit into the brass and pound the wood into the brass to hold it.

steve
 
In case you don't have it apart yet: Somebody locked the nut down against whatever holding force is applied by the sealing nut to the bearing. Put it back together tight, put a wrench on the mixture nut and tap (hard) the end of the wrench with a not-too-heavy item like another wrench. The sudden acceleration will be more effective than pure torque. I worry, though, that if you have spun the bearing against its seat on the carb body there may be terminal damage.
Bob
 
Alas, even the impact gun would not loosen the mixture nut. The idea of using a wooden dowel cut down to fit into the jet bearing worked great. Held it tight without damage to the metal, but with the nut locked on there like it was, it was a futile. New parts on order now. Thanks all for your input.
 
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