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well, I double checked my info on needle sizes last night. The most popular size used in the Morris Marina 1798cc single HS6 carbureted engine was indeed ZH, and it used a "yellow" spring in the dash pot. The alternative "rich" needle was a SA. The second most popular needle used in this same application (again, according to Haynes) was TW with a yellow dahpot spring. The TW rich alternative needles was the SW needle.

I compared the documented profiles, and came up with the ZH being richer than the TW in mid-range engine speed, but the TW was richer in the top end.

I also compared the profiles of the "rich" needles. The top 1/3 of the SA needle's profile was identical to the TW, but the SA's lower 2/3rds was the richest of the 4 needles. The SW needle's profile was "middle of the road" in the mid-range/lower 2/3rd of profile, but the richest of the needles in top end.

anyways... I think I've narrowed down my list of parts to choose from quite a bit... sticking with the ZH needle for now... need to change the dashpot spring to "yellow"...

Are float bowl covers interchangeable? If I can get one with ventilation hook-up for a charcoal canister, buying one will probably be easier than potentially butchering the one I currently have.
 
Should be interchangeable. The one on the other carb had a "T" supply, so's it'd supply the second carb, but no take-off for an evap-loss tube. No overflow either. That'd be ~perfect~ for what you need.
 
maybe I'll be able to find one somewhere...

I did notice that the current float bowl cover has a pin hole for ventilation though.
 
Look to the model aircraft stuff... mebbe find a small DIA. metal tubing and enlarge that weep hole *just enough* to swedge the tubing inna hole?
 
hmmm... sounds like an idea... could solder it into place if it works well enough, too...

Concerning rebuild kits... do you go off the model of the carb for the application to obtain the kit (e.g. AUD 580, etc.)?
 
I don't think soldering is a good idea: Pot metal! Plastics, babee, plastics. Epoxy.

You should be able to get a rebuild "kit" by simply specifying "HS-6, pre-'68". AUCS490 body.

I'm VERY encouraged to find that the Marina used the ZH needles. It was for all practical purposes an MGB engine in 'em. Should work pretty well without a bunch of "faffin' about."
 
yeah, me too!

Epoxy.... really? regular 'ole solder would get too hot? or just not bind well with the host metal?
 
You'll never get solder to "take" on potmetal.
 
ah... very well then. any preferred types of epoxy to be used in this binding process?
 
Hey Doc,

What model shed did this come from? I'm figuring that since the needle ought to be useable, I ought to get the SU carb rebuild kit for the model & year of the shed this came from (to keep things "easy").

I think the only thing I'll have to do that will make this carb different from the stock 'shed' unit is change the dashpot piston spring to a 8oz. (yellow) component.

So far, it's proving somewhat challening to find a rebuild kit for a single HS6... I guess it was deployed in pairs for the majority of applications. I may end up with one of those twin carb rebuild kits, as spares are a good thing to have...
 
Couldn't hurt! It was (I ~think~!) a '67, "B" somesuch engine. Kinda certain it was 1800CC tho. Too much water passed thru me earholes since I saw it. Well over 15 yearn ago... sorry.
 
ah ok... thanks! Even that small bit-o-info (with a bit more cross referencin') will help narrow down which kit should be the right kit. /ubbthreads/images/graemlins/thumbsup.gif
 
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