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HD6 jet diaphragm only lasted 8 months

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britndablood

britndablood

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Jan. Purchesed from moss
Feb. Intsalled and got the car running
Sept. Car is on the road and running great
Yesterday rear carb leaking badly from bottom
Has anyone seen this?
could it be ethonal?
Is there anything else?
I plan on calling moss tech today but want your insights.
 
Assuming correct installation, I have not had any fail in anywhere near that short of time.

In most of the instances I've seen, the diaphragms dried out from lack of use, not exposure to gasoline.

I've not personally experienced any ethanol related deterioration, so I have no insight there.
 
Ditto Randy's reply. I put new jets in my BJ8's HD8s probably 12-15 years ago and have had no problems (and I live in California--we've had ethanol, MTBE, you name it in our gas for years). My guess is an installation problem, or a burr or deformation on the carb bodies. Possibly, more recent production of the diaphragms have an issue (although I'd expect the SU people to know/do better).
 
There are cheaper diaphragms out there and higher quality diaphragms. For whatever reason, the ones Moss gets are spotty in their quality.

As always, either order these parts from a specialist like British Car Specialists or SU Burlen in the UK, or a perfectionist like Joe Curto. They will know what's good and what isn't.

Alan
 
Usually if they fail it's because one of the retaining screws has caught the diaphragm material as it goes in and torn it a little. It may not leak straight away, but it will soon enough.

In our experience they wrinkle up a bit and get stiff, but otherwise they are quite durable.

Ash
 
howdy all,
i too have had problems with MOSS supplied SU jet glands.
earlier this yr, & living close to MM in SB CA, I rejected several HD8 jets before i was satisfied.
problems found were,irregular neoprene castings,abraisions to the gland surface,day light through the membrane[cut-tear??]
the salseman did not agree,said they would be"returned to stock"
also said they were sourced from J CUTO.....
with respect 59er
 
So here is an update. Due to the timing of purchase I had a set that were made with a rubber that becomes brittle when ethanol is used. I called Joe Curto and he said that the new and improved version has a V stampped on the bottom of the brass. These are supposed to be resistant to the new fuels. On top of that Joe Curto is sending me replacments for free and paying shipping both ways. Thanks Joe
 
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