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SU CARB---CHOKE PROBLEM

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bluemiata90

bluemiata90

Jedi Trainee
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I've rebuilt the carbs on my 1961 TR3 and can not get the jet heads to move smoothly, so the choke linkage can move them. I rebuilt the jet assemblies with all new parts and in the assemble are 2 cork like gaskets that are placed on the jet head rod, one above and one below the spring. The rod will move freely before I install the gaskets, but is very tight after I install the gaskets. Once the gaskets are installed, the rods will not push all the way up after using the choke, so the carbs will run rich and out of sync. I've tried soaking the gaskets in oil, adding lithuim gease during assemble and each time the same problem. Anyone have any tricks, ideas, suggestions on how to get the jet head rods to move freely, so I can reattach my choke cable. At this time, I just start it without the choke and let it run till it warms up and then it will run great. thanks
 
Hello BM90,

it's a long time since I worked on 'H' type carburettors but from memory the jet nut should not be tightened all the way, just sufficient to squeeze the corks to prevent fuel leaking.
The other possibility is that the replacements are too small in bore so grip the tube. If the latter you could try to carefully open them up with a twist drill or round file and emery?
Your problem highlights the weak point of the 'H' type and hence the subsequent 'HS' which did away with that type of seal.

Alec
 
Alec, thanks for the post. The jet nut doesn't seem to tighten the seals and you are correct, the nut actually has to me almost 2 complete turns out, but that is for the jet head to work properly. I think I solved the problem, I once again took the jet assembles apart and added bearing grease on the cork seals before I replaced them. They seem to move smoother and that might be enough to get the choke to work correctly. As for the "H" type compared to the "HS" type, I truely never even knew there was a difference. You learn something new every day. Thanks for the information.
scott
 
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