triumphs
[Top] [All Lists]

RE: SU Needle Jets

To: "'Glen Murdoch'" <glen.murdoch@gat.com>
Subject: RE: SU Needle Jets
From: Randall Young <randallyoung@earthlink.net>
Date: Wed, 3 Mar 1999 09:30:23 -0800
Cc: "Triumphs (E-mail)" <triumphs@autox.team.net>
Organization: Navcom Technology, Inc
Glen :

Before switching to different needles, replace the jets (the part the 
needle goes into) and standard needles.  What you describe is a classic 
symptom of worn jets.  Fixing the symptom (ie rich at idle) leads to lean 
operation at speed, leading to another classic TR problem : overheating <g> 
 Unfortunately, I don't know of any way to check the jets, except to 
replace them.

If your carbs are SU's, check the side play of the pistons.  If they rub 
hard on the housings with moderate finger pressure, then you probably need 
new housings and/or pistons, too.

Randall

On Wednesday, March 03, 1999 8:12 AM, Glen Murdoch 
[SMTP:glen.murdoch@gat.com] wrote:
>
> After about 5 years I have finally started up a '62 TR4.  After doing the
> initial tuning I find the engine to be running rich (as determined by the
> smell of unburned hydrocarbons, spark plug condition, and exhast rhythm.
>
> The mixing nut has been fully adjusted up.  So I'm thinking the next step
> is to change to a leaner needle.
>
> Which brings me to my question do I want to go with (SL)s or (RH)s (moss
> catalog designation).  Currently I have (SM)s installed.  My first 
thought
> was to use the (SL)s but they appear to be shorter than the (SM)s which
> would allow more fuel into the mixture.
>
> The carbs are in good shape grose jets have been installed and the float
> bowl level checks out. Timing has been set at 4%BTDC per the manual, a
> compression test indicates 150 on all cylinders.
>
> Any thoughts or comments.
>
> Thanks in advance
>
> Glen
>
>
> 

<Prev in Thread] Current Thread [Next in Thread>