Lotus Elan and Lotus Elan Plus 2 Forums

I have an issue with a Weber 40 DCOE that I am hoping someone can help me with. I have one carb where one idle adjustment screw hole is stripped out in the body of the carb. Not totally stripped out, just enough so that if I back the screw out 2 turns it pops the screw and spring out of the carb. I tried cutting down the spring but there is just not enough meat left in the body of the carb to keep the screw from pulling out.I was thinking of using a jam nut but that does not look right and makes it tough for adjusting the idle mixture.


Have you ever run into this and do you have any ideas?

Zog,

Is it the idle mixture adjusting screw or needle valve that is in question?

Assuming we are talking about the idle mixture screw, if the thread in the housing is damaged, I think you need to replace the housing. I do not know if you can find a thread chaser to reform the threads in the housing sufficient retain the screw when under spring tension and prevent an air leak past the threads.

I think the best solution is to source a replacement carb, or carb body and new needle valve at the very least.

Bill

Any reason why a helicoil can't be applied? I assume it's metric, and these go down to some pretty small sizes.

As a temporary bodge, maybe some plumbers tape around the screw thread will keep it in place.

Robert

Loctite have a product that reforms threads in partially stripped components see link below. Good for relatively lightly loaded items like this, I would not use it on a conrod bolt . Worth a try as cheap and easy and if it does not work then I would try a helicoil after that. Aluminium foil wrapped around the screw thread may help as a temporary fix.

http://www.henkelna.com/adhesives/produ ... 7876355073


Weber also used two type of idle mixture adjustment screws. One with a long tapered point and one with a shorter point. I don't know what carbs used which version but maybe you have the wrong screw for your carb or maybe a change to the alternative style screw could help if it engages the body threads better

cheers
Rohan