Rich,
There are three things that come to mind, the third one, being, I think the
most likely.
1.) You have checked, and the piston in the middle carb moves freely?
2.) The carb insulators / gaskets are intact with no gaps?
3.) In order for the throttle linkage to turn the throttle shaft and throttle
plate (butterfly) in the carb, the tiny forked lock washer on the carb's
throttle shaft have to be intact. This keeps the nut between the throttle
shaft and the throttle linkage from loosening. If this loosens, the linkage
will rotate but the throttle shaft in the carb will not, and the carb throat
will stay closed. -Also if the throttle disk was installed wrong-way-round on
the carb's throttle shaft, the bevel in the disk can cause the throttle to jam
closed.
Also, there is a "lost motion" lever on the throttle shafts for the front and
rear carbs. It is pinned to the shaft with a tapered metal pin. You will want
to check that the pin is not missing or broken, allowing the lost motion lever
to rotate without rotating the throttle shaft in the carb.
If these descriptions are unclear, contact me off list. I can e-mail you the
appropriate pages from the Factory parts list if you do not have them, and
would want them.
David W. Jones
'62 Mk II BT7 tricarb
Cumberland, RI USA
----- Original Message -----
From: Rich C
To: Healeys
Sent: Sunday, June 19, 2005 11:09 PM
Subject: Tricarb Mystery
Here's a situation that has a number of the experts really stumped:
Totally rebuilt tricarb Mk 2 engine with fully rebuilt carbs.
Problem:
- number 2 carb is not working, as in... will not pull fuel into cylinders
3
and 4.
- therefore engine is running virtually on carbs 1 and 3 feeding and
running
cylinders 1and 2, 5 and 6 respectively
- #2 carb soon becomes cold to the touch while 1 and 3 warm up normally
Upon further investigation:
- all carbs completely rebuilt using genuine S.U. parts.
- fuel supply getting to all 3 carbs
- good comression on all cylinders
- good spark at all plug electrodes
- even tried substituting plugs, no difference.
- with engine idling there is absolutely no draw into #2 carb throat and
the
fuel just sits there in the throat of the carb.
- temporarily plugged and eliminated balance pipe at inlet ports to try to
further isolate symptoms.
- with all carbs removed, there is good srtong suction pulling into all
inlet
ports equally.
How's that one for a puzzler? We're stumped, any ideas?
Rich Chrysler
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