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Grosse Jets

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The rumor is that the quality DID change for the worse a few years ago but is now back to original quality. I think that some folks are not sure if there are old, inferior, jets still in dealers stocks. Maybe some found that they didn't need them in the first place.

I personally have never had trouble with the SU jets & don't feel the need for something "improved".
D
 
Thanks Dave,

The needle valve in my front H4 is giving me fits, that's why I thought about it. I just can't seem to figure out the code on how to get it adjusted to where it will let enough gas to the carb w/o it over flowing.

I miss the HS's from my Sprite and the MGB, less fidgety to work on.

BTW, I'm very happy to see your post, welcome back, we missed you.

Patton
 
HI Patton, Yes some Grosse jets did give problems ,however, not only did the quality improve a complete new design was introduced and mine are flawless .I would'nt set a SU up without them.-FWIW---Keoke
 
Hi Patton,
Sorry you're having so much trouble.

The only time that I ever had trouble with a SU inlet, I found that the seat was not tightly screwed into the float top & fuel was leaking around the seat. There is supposed to be a fiber gasket in this joint.

The bottom of the needle, part that contacts the float, should have a small plunger with a coil spring inside. this plunger should be free to move in & out a little bit.

With the float chamber top inverted, & the plunger spring NOT compressed, there should 7/16" clearance between the pivoted needle operating arm, on the side opposite to where it contacts the float, & the carb top mounting surface. 7/16 drill bit should just slip into the gap.

If there is a burr or scratch on the inside of the seat where the needle contacts it, it will never seal. This can sometimes be cured by lapping the needle into the seat using a mild abrasive such as Comet Cleanser. (Remove the seat for this operation & thoroughly clean the spring & plunger after)

Forgive me if I am covering basics that you are already aware of.
D
 
I don't mind recovering the basics, I might miss something.

The fuel is coming out the overflow area around the cap nut that holds the float chamber lid.

The problem is all in the operator. A PO bent the arm up, and had it adjusted close enough that it would not leak when the fuel pump was charging the system, but if I run it a while, it would start to leak.

When I removed lid, the hinged lever for the float was bent incorrectly in the middle of the lever. Someone also appears to have spread out the curved part somewhat from clean "U" shape. I am trying to straighten the arm, and readjust the curved part.

When I set it to what I though was right, the car was not starting and sounded as if it was not firing on all cylinders. The leak is gone.

Since this is the only thing I have worked on, I am assuming that the needle valve is fully closing, but not opening, and the carb is not getting fuel. The problem is finding the spot where the fuel is flowing as needed, but it does not leak out the overflow in the top cover when not.

When I tried to adjust it again, the leak is back in force. I stopped by the local LBC shop today, they didn't have the levers, but they did have Grosse Jets (no needle valves) so I can try that to see if it helps. There is an MGA guy nearby I am going to try to pester for a loaner part.

Meanwhile, the battery on the car died, so testing is finished till I get that fixed.

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Patton
 
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