[TR] SU Fuel Problem

[John Macartney]

Scott

Irv gave you a good pointer about the floats themselves, but here's another. The Delrin needle valve 
in the float chamber itself is notorious for sticking - either open or closed. I first encountered 
this in 1962 - and nearly every year since then, so it's not a new phenomenon.
The valve itself is likely made of hard, white nylon, is spring loaded and has small fins. Glues and 
muck in the fuel creates a build-up and this means the valve sticks and even fuel delivery pressure 
won't shift it. Take it out and with some fine sandpaper or glass paper, carefully and gently 'sand' 
the fins and just enough to grind off the glues. Then, wrap the sandpaper round a cotton bud - 
abrasive side to the outside and work it up and down its housing in the float bowl lid. A good blast 
of air on both should dislodge any dust. Put it back together and it should then work again as it 
should. When I had cars with SU carbs, this task was a routine one to be done once a year in the 
days of leaded fuel. Then unleaded came along and I had to do it every three months!

Jonmac

----- Original Message ----- 
From: "Irv Korey" <emanteno at gmail.com>
To: "Scott Suhring" <suhringtr36 at comcast.net>
Cc: "Triumph Mail List" <triumphs at autox.team.net>
Sent: Monday, April 27, 2009 7:32 PM
Subject: Re: [TR] SU Fuel Problem


> On Sun, Apr 26, 2009 at 9:15 PM, Scott Suhring <suhringtr36 at comcast.net>wrote:
>
>> A friend of mine is having problems with his SUs that we just can't figure
>> out.  Here is what he is experiencing:
>>
>> My 1970 TR6 is seeping fuel out of the rear SU float bowl overflow tube.
>
>
>
> What kind of floats are in your friend's SU carbs? There have been some
> problems with today's gas and the brass floats found in the H series SU's.
> The solder on the float fails, the float gets heavy, and gas comes out of
> the overflow. I think the HS floats are plastic, and I haven't heard of that
> happening with those, but it is worth a look.
>
> Irv Korey
> 74 TR6 CF22767U
> Highland Park, IL
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