OK so it seems that the fuel level is fine. If it is running rich (as it
seems to be) then the needle and jet may be wrong.
You need a AAN needle in a .090 jet that has a RED plastic head, and, if
present, blk/grey and blk/brn bands on the hose
To check the needle number, you need to remove it from the piston and then
remove it from its collar. THe number is inscribed
lightly on the shank on the needle.
One possibility or running rich is that the needle is not positioned
properly. IF it is retracted too deep into the piston, then the jet can
not be set high enough. I had this happen one to me on a biased-type of
needle when I failed to place the spring properly on top of the needle in
the piston.
The proper sequence is spring on top of needle, and needle inside of
collar. This this whole thing stuck into the piston and set there with the
little arrow on the collar facing the (front or rear of the carb (check the
arrow orientation before removing). The collar should be set flush with
the bottom of the piston. The needle should be angled slightly off center
and FREELY mobile with light pressure.
Does this help?
___________________________________________________________________________
____________________________-
Message text written by INTERNET:owner-triumphs-digest@autox.team.net
>Date: Mon, 24 Mar 2003 17:10:32 +1200
From: david@robertson.org.nz
Subject: More on Spitfire running rich
Hi,
First, thanks for all the replies - you guys are great!
I decided to start from scratch. I've replaced points and plugs. Gap set
correctly for both, dwell is within spec, timing is correct. So I'm
confident the ignition system is OK.
I then took the piston chamber & piston off both carbs . Needles look
fine. They're spring-loaded ones & I can't see any ridges or flat spots on
them. The tubing attached to the jets looks much cleaner than the rest of
the carbs - maybe recently replaced by previous owner?
Both jets were very high. I adjusted them down to flush with the bridge,
then another two complete turns. I turned the engine on the start for a
few seconds with the coil lead out. I can see petrol a little down in each
jet - not overflowing and there's no sign of petrol leaking from the carbs
or float bowls.
I put everything back together & started it. It's VERY rich. Black smoke
out the exhaust, won't idle at all. I adjusted them both up two complete
turns and it idles but it's rough. Drives rough as well. I tried some more
adjustments on the carbs individually - adjusting the rear one as far up
as it will go seems to help, but even there it's too rich. If I lift the
piston with the pin, the engine speeds up.
Adjusting the front carb doesn't seem to do anything - it doesn't get
better or worse. Lifting the piston doesn't change the engine but it
almost stalls when I drop it back.
I took plugs 1 & 4 out & they're both really sooty.
I'm suspecting that jets, needles or both are very wrong. Any comments?
How do I tell what I've got? I guess I can just order the correct new ones
& see if that helps but I won't be very happy if it's something else.
Regards,
David Robertson<
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