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How to swell OS7H o-ring's?

VTMTNS

Heliman

Vermont

Hi, my OS7H (1980's vintage) midrange/idle "needle" o-rings are leaking. After two tanks of fuel hovering yesterday, I am getting foamy fuel from the seals, and engine quitting at mid-range.

Is there a way to swell the old o-rings? Automotive Brake Fluid?

Any suggestions appreciated. Thanks!

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06-26-2005 Over year old.
nivlek

rrProfessor

Norfolk England

Acetone will do it , or so I am told by my clubs resident industrial chemist . You could just add a couple of percent to your fuel , I have been advised that even diluted to this extent it will still cause the seals to swell . I found out because I had asked with the intension of trying a small percentage of acetone because of certain benefits that it is supposed to have , but as it is likely to swell the "O" rings I decided against it .

Or you could get really radical and fit new rings .

At the end of the day , it gets dark .

06-26-2005 Over year old.
VTMTNS

Heliman

Vermont

Automotive Paint thinner worked

I had some nasty automotive paint thinner, a few minutes of soaking and the rings swelled nicely to form a great seal again. Thanks!

06-26-2005 Over year old.
crowfly

Veteran

Pleasant View, TN U.S.A.

Are new O-rings still available for your engine. Many "swelling tricks" are short lived.

If God had meant for man to fly, he would have given him more money

06-27-2005 Over year old.
cforcht

Key Veteran

Chelsea in BFE Iowa

yes it wont last long. they usually go back once the thinner is evaporated. I cant imagine you cant get new O rings for it.



[b]heli flyer by day, custom making cnc heli parts by night[/b]

06-27-2005 Over year old.
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TMoore

rrMaster

Cookeville, TN

The only thing that I can think of for that carb is to jack it up and slide a good carb like a Supertigre underneath it.

They sucked back then and if the o-rings aren't copacetic now it will really suck.

TM

06-27-2005 Over year old.
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How to swell OS7H o-ring's?

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