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Triumph TR6 - too lean can't adjust

'76 tr6, newly rebuilt engine & carbs. Runs horrible since rebuild by a triumph-only shop in CT. Oil in dashpots is fine. Won't stay running and idles horrible unless choke is fully pulled. Turns over well but starts hard. Once fully warmed up it has to run with choke 3/4 out. Behaves better under load above 2000rpm. When engine temp gauge gets just over halfway, it sometimes dies and then impossible to start until it cools. Embarrassing at stoplights. Mixture adjustment screws all the way in, being the only way it will run. Sprayed ether and also gumout around intake and the likely vacuum leak areas with no change. Disconnected and plugged vacuum ports with no change. If I take off the aircleaner and plug the rectangular ports in the carb intake horn, it finally runs better and can run a little rich. Definately too lean somehow. Gonna part car out and junk the remainder if it keeps causing so much frustratration!
t bear

I'm mo expert but is the timing, gap/dwell, valves adjusted properly.
JT White

I would say there is something fubar in the carb rebuild.

How's the fuel pressure and supply?

Sounds like timing and headspace to me!!
Doug Baker

I'd agree with Doug...gotta make sure timing is correct or you'll never be able to adjust carbs /
Other points to there a vacuum line from the carbs to the dist ? if so does it change idle when you remove it from the dist ? you should feel suction at the dist end.

Good'll get it right
Charlie B.

They probably adjusted the float setting so that the fuel level is too low. You need to change the setting in 2mm increments so that the fuel level is higher. It's supposed to be 16-17 mm from the bottom of the float (it will be upside down) to the flange. Decrease that setting to increase fuel level.
Brent B

Are the valves timed (and adjusted) correctly?

What does the "triumph-only shop in CT" say or better still what are they going to do about it?

In the carbs...are the diaphrams in good shape (no holes)?? Have you ballanced the carbs? This will make an engine run rough if not ballanced.

Rick Crawford

I've been following your post. What's the update? Did you check your timing?

the triumph shop did all the work, all the timing, all the rebuilding, machining, etc. A lot of money was spent and it's too much trouble to haul the car back there (6 hours each trip). They claim it was running fine when they finished job, but I noticed they had to keep it choked to load onto trailer. Figured it was just cold-blooded and would straighten out when warmed up and broken in.
t bear

If you haven't figured it out yet... go to go to technical then go to carburetors and print the 3 steps. OH... and check that the big fat gaskets on the carbs line up with the notch / step on the top of the carb... this choke required for running sure sounds like a vacuum issue / or timing... and is that fuel pump installed properly for proper line pressure... disconnect the line going into the carbs and get someone to turn it over for you ... gas should shoot out pretty good and with your thumb on it gently gas should squirt all over your shirt. The rest of the ideas up there fit in also... but it runs with the choke out which sounds like carburetors in some form or ilrepute.
good luck. Garry
Garry Burgess

This thread was discussed between 26/04/2010 and 28/05/2010

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