Subject: [TR] SU H6 float question

From: [email-masked]
Date: Wed, 1 Aug 2012 05:37:39 -0400 (EDT)

Hi all;
 
My TR3A has had a running problem for a long time that I have not had time  
to address. Finally, I am getting around to spending a few minutes here and 
 there on it.
 
After I drive it for 10/15 minutes, there is a very sudden loss of engine  
power and hesitation in the engine. I can usually maintain momentum for a 
couple  of minutes and then the engine dies. Five minutes later, it starts 
fine. I've  replaced everything ignition related, as well as fuel filter.
 
I drove the car a couple of weeks ago. As soon as the engine lost power, I  
pulled over and removed the top of the float bowls. The float in the front 
carb  was floating. The float in the rear carb  was not, and there was no 
fuel in  the bowl. There do not appear to be any external leaks in the carbs.
 
Am I safe to assume this is a float valve problem?
 
Tim

** [email-masked] **

Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
Unsubscribe/Manage: http://autox.team.net/mailman/options/triumphs/[email-masked]

---

From: "G.D. Huggins" <[email-masked]>
Date: Wed, 1 Aug 2012 07:25:21 -0500

Sounds like the rear valve sticking closed could be an issue, but also the
fuel line between the carbs could be blocked somehow.
Simple tests on each should reveal the issue.

Are you running the original-styled needle valves or the ball-styled "grose'
valves?

On Aug 1, 2012, at 4:37 AM, [email-masked] wrote:

> Unsubscribe/Manage:
http://autox.team.net/mailman/options/triumphs/[email-masked]

---

From: Bob Labuz <[email-masked]>
Date: Wed, 01 Aug 2012 07:56:15 -0400

Tim,

Same problem here a few years ago but on the front carb. I was using the 
Gross (SP), jets and could not figure out why they were sticking closed. 
So I replaced them both with the original ones from Moss and problem solved.

I have heard others mention that they are not fans of the Gross jets.

If you have the stock jets, just replace them with new ones. Problem may 
be related to the alcohol in the gas but not sure. Could also be varnish 
or some other junk in the jet.

Bob

---

From: "Randall" <[email-masked]>
Date: Wed, 1 Aug 2012 12:42:11 -0700

> Am I safe to assume this is a float valve problem?

I would not assume that, especially since you say the engine dies completely
later on.  Incoming fuel is routed to the front carb first, so if there
isn't enough to feed both carbs, the rear carb is the one that starves.  And
the engine will run (although not well, dies at idle, etc) on just the front
carb.

I would be looking for a fuel delivery problem first.  Most "vacuum test
gauges" will also measure fuel pressure.  Tee it into the fuel line and prop
the gauge under a wiper arm so you can see it when the engine starts to act
up.
http://goo.gl/HnvRG

As I think someone already mentioned, you can try leaving the fuel cap open
to be sure it is not a tank venting problem.

-- Randall