Hi everyone. Thanks for all the responses about altitude. Summary so far
is as follows:
1. Yes, lots of folks have had trouble tuning the later "emissions" carbs
(mostly late TR6 and early TR7) for high altitude. These carbs (and
needles) do NOT really allow a very wide range of mixture adjustment.
Seems like I have the makings of another article for TVT here!
2. Several have heard of high altitude kits (new needles) retrofitted to
these "troublesome" emissions carbs. One person actually reported having
it done and commented that the new needle had the same number (I guess)
with an "H" suffix. Interesting.
3. Burlen seems to be THE place to get replacement/alternative needles.
I'm going to FAX them someday soon and tell them of my problem and see what
they recommend. I'll let you all know.
However, a few of you have also mentioned Option 4 (not listed above) --
resetting the float levels to yield a leaner mix. Here's my question.
Have any of you systematically played around (or know someone who has) with
the float levels on your carbs to see what effect a small change (couple of
mm) really has on the mixture? I could do this myself if necessary but
thought I'd ask the netizens of these two lists first. I figure a few
minutes on the web might be worth an entire day of playing around :-) I
think it *must* effect things somewhat but the questions are (1) how much
and (2) what do you screw up by not having them set the way the
factory/carb manufacturer intended??
Thanks, you've all been a big help!
Jim TenCate
'80 FI TR8 (NO altitude problems :-)
'74 TR6
|