[Healeys] HD6 jet adjustment

[Bob Spidell]

Good point, Gary.

Also, a good first step would be to remove the vacuum 'dashpots' and 
inspect the jets for out-of-round; if the jets are off-centered for long 
they will get oblonged and the needles might have a flat spot, making 
fine-tuning difficult. I only have HD8s but, IIRC, the jet-centering 
collars can only be reached, for all practical purposes, from underneath 
(not an easy task). Not as cheap as they used to be, but this little kit 
has come in handy, and it has a plug used for centering the jet collar 
that works well and they can get 2-3 carbs reasonably well-synchronized.

https://mossmotors.com/386-300-carburetor-tool-kit-su?gad_source=1&gclid=Cj0KCQjwtsy1BhD7ARIsAHOi4xYxV1_gx0C6U51f4fS5rS9FuYhAwbsD9dnKWxoYGi_BtM3jJp2oQ3IaArpvEALw_wcB

bs

On 8/7/2024 7:39 AM, warthodson--- via Healeys wrote:
> The fall rate test is for the piston fit in the chamber not the 
> centering of the jet(s) on HD6's.
> The air cleaners need to be removed, not easy on a tri-carb setup, to 
> gain access to the jet centering fittings. It is difficult for me to 
> think all 3 needles are not centered.
> If all three carbs have failed the piston fall rate test, my first 
> thought is that the pistons have become mis-matched with their mating 
> bell housings.
> Gary Hodson
>
> On Tuesday, August 6, 2024 at 02:51:47 PM CDT, JSARCH via Healeys 
> <healeys at autox.team.net> wrote:
>
>
> I would say most likely based on the attached instructions the SU 
> Service Manual. There is a specification for the fall rate of the 
> piston, at least for the HS4 carbs. You might find it on the SU Berlin 
> website. https://sucarb.co.uk/technical/category/hd-type-carburetters
>
> John
>
> *From:* Healeys <healeys-bounces at autox.team.net> *On Behalf Of *Simon 
> Lachlan via Healeys
> *Sent:* Monday, August 5, 2024 7:09 AM
> *To:* Healeys <healeys at autox.team.net>
> *Subject:* [Healeys] HD6 jet adjustment
>
> I’m told that the jets on my HD6s are not quite correctly centred. The 
> pistons do not fall fast enough nor with a satisfactory“click”. I have 
> three of them in my MkII BT7. Do I have totake the carbs out or can it 
> be done in situ? Not a lot of room……..
>
> Simon
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/healeys/attachments/20240807/cdc4a73e/attachment.htm>