Tim,
I run H6 carbs on my TR3 with RB or RF needles (I don't remember!)
I've rebuilt them a couple of times and haven't had any starting
problems, except the usual - stick your open hand over one of the
carbs to simulate a choke- trick. I set the jet a little differently,
I turn the adjuster bolt until the jet is level, then turn it down 12
flats, safety wire it, and go two more flats. 14 flats from level.
No troubles whatsoever. I assume all the choke gear has been removed
from your carbs?
~Steve
On May 28, 2010, at 12:04 PM, Tim Murphy wrote:
I need some suggestions on a hard starting problem. The car is a TR4
with
SU H6 carbs. I have the Kastner G3 cam and the RB needles in the
carbs as
recommended by Kas. The car used to start and idle pretty good. Then
I had
the very worn throttle shafts replaced in winter 2008-2009. Last
summer at
Blackhawk we experienced hard starting due to flooding when starting.
It
starts right up but idles at about 1000 -1500 RPM and the engine wont
rev
up until the extra fuel gets run out. This takes about 30 seconds
with the
fuel pump off. During this time the EGTs are at about 600 indicating
very
rich. Once it gets cleaned out it idles good at 1500 2000 with the
EGTs
at 900 to 1000. I discovered I had the stock SM needles in the carbs,
pushed all the way up in the pistons to give richer running. I
replaced the
SM needles with the correct RB needles and the car started pretty good
in
Sept. at Elkhart Lake. This year in May at Gingerman we started to
have the
hard starting problem again. Discovered another sinking float and
replaced
with a good one. We still had the starting problems where it starts but
wont rev up until it gets cleaned out. We also had a bit of a stumble
coming out of some of the faster corners.
I replaced the needles and seats thinking it was loading up on some
of the
corners. The old needles and seats were all brass and showed some
wear; the
new ones from Moss have the viton tips. I still have the starting
problem
where it wont rev up until it gets cleaned out. I tried checking the
fuel
level in the jet with the pistons and needles out and it seems to be
about =
down from the top of the jet. With the needle in displacing some of the
fuel Im guessing the level would be about at the top of the jet. Im
not
really sure what the best way is to check the fuel level in the jets.
The
floats were set with the SU tool, the oval shaped tube, and I have the
7/16
inch clearance specified, probably within a 32nd of an inch.
Any suggestions of what to check or take a look at and try would be
appreciated. The problem seems to have started when I had the throttle
shafts redone, closing off the extra air getting into the carbs. The
jets
are both set to about 10 flats down from full up and the EGTs run
around
1200 at WOT in 4th down the straights.
I did notice after putting in the new needles and seats and turning on
the
fuel pump with the pistons and needles out that I got a pretty good
slug of
fuel shot up out of the jets until the floats came up to seal off the
flow.
Thanks,
Tim & Ryan
1961 TR4 #317
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