Hello:
I've got a 77 Olds 403 in a GMC motorhome (which has the Toronado front end). Recently, I had to replace the needle and float in the stock Quadrajet carb due to a sunk float. After getting it back together, I realized that I did not put in the needle hook properly to the new float arm. I ended up putting the hook through one of the small holes in the arm, thinking it would secure it better, rather than over the flat part of the arm. I've done some reading and I see this is not recommended. However, I examined it carefully when I was putting it together, and I don't see how this could cause any problem. When I was adjusting the float level, I noticed that even when the float is completely down (no fuel in the bowl), that it doesn't even pull on the hook that I can tell. And the needle moved freely without any issue. Plus it looked like no matter where I hooked it, the needle would hang the same way. So, I'm not even sure if the hook is really that important. My main concern was that it wouldn't bind up which to me it would seem the chance of this happening would be greater with the hook outside of the holes.

This pic is exactly like my carb, and as you can see, the holes are perfectly lined up back-to-front, above the needle. They are actually offset the same amount as the curved edge where it is recommended to put the hook:
http://67-72chevytrucks.com/vboard/a...1&d=1289338473
I've seen others where the holes are further to the back and with those I can understand there would be a problem.

This also brings me to the second question, is this carb more reliable with the hook removed? I've read a few posts on this as well. I don't understand what the hook really does as I've read that the fuel will push up the needle anyway to open it up, the float just closes it and pushes down from the top. Just trying to get some opinions as I really don't want to tear this thing apart again, but will if I really need to. Just want it as reliable as possible so that it's not an issue out on the road somewhere.

Thanks very much.

 

It is pretty easy to carefully remove the top plate and with a small screwdriver or razor blade go around under the top gasket and lift it without tearing it. Open up the gasket with a small screwdriver by the power piston and feed the gasket carefully over the power piston and rods. I would be concerned with the needle binding with the hook through the hole but you say it is fine so then either worry about it or don't. My other thought is the needle would not be centered properly under the float arm for the top of the needle to hit the float and stop at its specific spot, causing a high float level. The hook I feel may help keep the needle from being pushed out or getting ****-eyed in the seat when fully open. These are just my thoughts and opinions. If it is not binding and is running well then drive it. : )

 

Thanks for the reply! Yes it is not binding at all, and it runs great. When I put it back together I made sure that everything fit together and it worked without binding. I think I'm going to leave it as-is and like you said, drive it. I've read about the hook binding the recommended way (hook not in the holes), too, so I guess there's always a chance that something can go wrong anyway. We will see what happens.

 

Every GM reference makes clear that you can not install the needle with the hook through the hole.

I do not know exactly why you can't, because I have never tried to do it that way.

Look at it this way: it's a lot like crossing the beams - It Would Be Bad.

As for removing it, GM did not spend 3¢ or so per little hook on probably tens of millions of carburetors for no reason.
Leave it on.

- Eric

 

I've always wondered that too, but maybe some applications are slightly different, and the holes are spaced a little differently and they bind. So, GM just warned not to use the holes on all of them. As far as no hook at all, I think I remember reading somewhere that no hook sometimes resulted in a very slight delay in opening the needle, which would lead to a slight roughness. I interpreted that as the hook slightly loosened the needle and it opened smoothly, but without the hook, it just kind of popped open and gave a slight roughness.

 

Good point Brown on the hook opening I can totally see that. It makes sense.

 

No hooks on my Q-Jets, and no issues..jmo

 

I am following up to this as this is exactly what I was thinking, too, maybe just a blanket statement saying "don't do this", even though it might work OK in some specific situations. I ended up leaving the hook in the hole, and I've put on well over 300 miles and so far not a single issue. I also recently had a close look at the old float and needle that I replaced, and I could see where the old hook had worn a spot on the float arm. It is right at the edge, and I mean right there... I don't see how it even stays on without falling off or slipping over the edge, or even worse getting stuck under the arm. So, for now I may end up leaving everything as-is and see how it goes. I'm in no way doubting all of the carbs out there and the reason the way it is, but it just looks like it would be prone to problems. I appreciate the feedback!!