[6pack] tr6 high idle continued

[Ed McGuirk]

The lifted piston in the rear carb strongly suggests that all the extra 
air is passing under that piston. You probably do not have a leak ( a 
leak would not raise a carb piston), you probably have an out of sync 
throttle plate or linkage. I think your next step should be to look 
closely at the rearmost throttle plate. How it sits at idle and how it 
moves with the other throttle plates and gas pedal. You probably will 
not be able to lift the piston and see the throttle plate with the 
engine running. You may need a flashlight and a mirror to see down the 
carb throat.

ed

On 2/4/2013 2:00 PM, 6pack-request at autox.team.net wrote:
> Date: Sun, 3 Feb 2013 14:08:07 -0600
> From: "Dave" <dave at ranteer.com>
> To: "Triumph 6 Pack" <6pack at autox.team.net>
> Subject: [6pack] tr6 high idle continued
> Message-ID: <CA9F99F9AB1541E9A07E1E2D00EBBE34 at Datsun>
> Content-Type: text/plain; charset="us-ascii"
>
> update on tr6 idling high.   triple carb, mild cam, etc
>
> Here's what we did this morning:
>
> 1.  found what looked like a vacuum port in the bottom of the middle carb and
> blocked it off.  it is likely once upon a time connected to the dizzy, which
> no longer has a vacuum connection.
> 2.  blocked off all three vacuum ports on the top right of all three carbs.
> these were connected to the valve cover, brake booster, and vapor recovery
> canister.
> 3.  the car started, and idled very nicely at around 1200.  but then as it
> warmed up, the idle increased back up to around 2500
> 4.  checked the position of the pistons in the 3 carbs.  the front and center
> carb were more or less sitting at bottom, but the rear carb (by the scuttle)
> the piston was noticeably raised.  blocking off that carb completely killed
> the engine.  slowly blocking it off lowered the rpms, the more we blocked it.
>
> what next?