Update on Header and Jetting

John Soliday johnsoliday at msn.com
Mon Apr 19 08:58:57 PDT 2010

So I have to make a phone call to dynojet today because the jet kit didn't
work at all with the Jarding 4:1 Header.  Now recall I live at ~ 5400' above
sea level so all jetting that works for sea level is off the table up here.


So I installed the header and as a good engineer decided to "baseline" it
with the stock jetting.  It ran fairly well which was to be expected if the
bike's stock jetting was "lean" from the factory, then it's a bit "rich" up
here due to the lack of O2.  Therefore, one would expect the "rich" jetting
to work fairly well with a pipe which it did.  The only thing I noticed was
a slight hesitation when rolling on the throttle a bit of surging at steady
speeds so I figure it's a bit lean from those symptoms.  So I decided to put
leaner of the two dynojet options into the bike, noting that this is not a
high altitude kit.


So as is to be expected getting the carbs out is always a pain, actually
it's harder to get them back in than out, but I had all of Sunday to do it,
and had finished my coffee for the day and had a cold one handy.  While I
was at it, I took all the evaporative emissions crap off as it was in the
way.  Maybe I'll block off the air injection system next time.


Once the bike was back together sans bodywork, it started right up and idled
just fine, the rest of it's running is horrible!  If you yank the throttle
while in neutral, the engine will die.  I could ride it by slipping the
clutch and feathering the throttle to get the revs up but it wouldn't pull
at all off of 1st gear!  I rode it around a loop and was truly a hazard to
myself and other's as I wanted to warm it up to make sure of it's operation.
So the question is, rich or lean???  I'm betting I'm way to rich now, given
the stock jetting is supposed to be leaner than a dynojet kit.  If that is
the case, the jets supplied by dynojet probably are worthless, but I hope
the needles and replacement springs are OK.  Dynojet had told me to get some
100 main jets (vs. the 104 and 108 in the kit, and 110 stock) and drop the
needle to the first clip (thus no more adjustment range if I need to lean it
further!  I suspect when I call them, that's what they are going to tell me
to do, seems pretty small in the main and it seems to me if it won't rev in
neutral, that one clip adjustment isn't going to cut it but I'm older and
wiser and not in a hurry as I have the KLR to ride in the mean time.


More updates soon, and maybe I'll change that shifter shaft seal while I'm
at it.





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