HS2 jet assembly fuel pipe

[nelly]

Don;t think I've posted on here before...but hopefully somebody can advise! I was trying to remove the nylon fuel pipe that connects the jet assembly to the base of the fuel chamber (don't ask!) - the fuel pipe came out with the nut and a metal washer but I think there is meant to be some sort of rubber 'olive' on the end? I think this is still inside the fitting in the base of the fuel chamber. If we can get this out is it possible to reattach all the parts to reconnect the fitting or will we need a new jet assembly?!

Thanks,

Sam

[firedrake1942]

This may assist in understanding what yay have and what may be missing

http://sucarb.co.uk/carbspec/carburetto ... s/id/1907/

[nelly]

This may assist in understanding what yay have and what may be missing

http://sucarb.co.uk/carbspec/carburetto ... s/id/1907/

Thank you, that did help, we managed to free the rubber olive and reassemble successfully. The next problem was the locking nut for the jet bearing took a whole morning to loosen, thought it was never going to!! Lots of PlusGas, a new 18mm socket and a lot of straining did the job! Surprisingly nothing else seemed to be damaged in the process!

Now to the next problem. We have fitted a used HS2 from a 1098cc, with AN needle in. We bought a GG needle (as specified for for our 803cc). However, even after an afternoon of attempting to centre the jet, the needle still sticks. It just doesn't seem to want to centre. I don't think there's enough play in the jet and the needle just won't line up. We tried starting the engine with the best we could get it but the piston just got stuck when the engine was running.

Going back to the AN needle and all is fine. Is it safe to use this needle temporarily - I assume the mixture will be slightly too rich?

What is the next step? New needle in case this one is bent (looks ok to the eye)? New jet bearing? New jet?

Thanks for any suggestions!

[myoldjalopy]

I'm guessing here but - surely the needle should fit the carb, not the car?? A needle specified for an 803cc H1 carb wouldn't work too well in an HS2, I would have thought. It should be possible to adjust the mixture OK without running rich.
If I'm wrong in this, I'm sure someone with more knowledge will come along soon and clarify.

[nelly]

I'm guessing here but - surely the needle should fit the carb, not the car?? A needle specified for an 803cc H1 carb wouldn't work too well in an HS2, I would have thought. It should be possible to adjust the mixture OK without running rich.
If I'm wrong in this, I'm sure someone with more knowledge will come along soon and clarify.

Yes, I thought about that. Also, about how modern fuels will be very different than when the original specifications were given. But have to start somewhere!

Although the GG needle was specified for the H1 carb not the HS2 (for the 803cc), the Austin A35 848cc engine used a HS2 and the 'weak needle' is a GG. And since the larger a-series engines seem to like progressively 'richer' needles (the 948cc Minor HS2 uses the 'M' needle as standard, which is stated as the 'rich needle' for the 848cc), I figured that GG does sound about right for the 803cc engine/HS2 pair, even though it's not the H1 it's going in.

Again, I might be way off in my thinking, but thought it would be a good place to start!

[myoldjalopy]

But you say the GG needle doesn't work and the AN "is fine". So I doubt its a problem with the jet. Either the GG needle is bent (although its not apparent, you say), or its incompatable with the H1 carb. I would be tempted to adjust the mixture as best you can with the AN needle and see how the car performs and what petrol consumption is like.........

[nelly]

Thanks. A GG needle should fit a HS2 SU, as they have the same size jet - the needles are the same for both the H1 and HS2 carbs, and the GG is listed by SU for applications using both HS2 and H1 carbs. The AN fits but is very unlikely to give a good mix all the way through the range of the engine, as this needle was specified as being used for larger engines (and the HS2 only has one adjustment for mix at idle - the needle determines things after that). The application determines which needle to use. As the 803cc was never originally used with the HS2 carb then there is no needle specified for this application, but the GG looks like it would suit quite well.

We have ordered a new GG to fix or eliminate the needle being faulty. After that we will look at replacing the jet if necessary. Just sticking with the AN is not really solving the problem - something is wrong if the GG doesn't fit.

[myoldjalopy]

OK, well let us know how this pans out - it would be interesting to know the answer to your conundrum.

[nelly]

OK, well let us know how this pans out - it would be interesting to know the answer to your conundrum.

Thank you, I appreciate your input! Will report back.