I too had my triple carbs running to lean, my engine is a 1969 HE (now with
9.5:1 compression), with a Piper 270 cam, stock exhaust manifold. The stock
carbs were the nonadjustable ones, which were converted to B1AF needles. The
extra carb was from a 68 TR250, the '69 and '68 TR250 are the only carbs that
are the same. All other years are different.
I was hard for me to hear the engine speeding up since the dashpot cover has
to be off for adjustment and you have to push down on the allen wrench to
adjust the needles. My tool of choice is a Color Tune. With the adjustable
needles I was unable to get the mixture to richen up enough. So I chose
another method of "adjusting" the needles.
First measure the depth of all three of the jets. The Depth from the
aluminum carb body to the inner edge of the jet. When I did this I noticed all
three were different.
I obtained either a 1/4 or 5/16" bolt whacked off PART to the threaded
section so the threaded end would be flat. Then jammed two nuts together and
slipped a flat washer on the end of the bolt. Then adjusted the nuts plus the
washer to give me the same measurement as the lowest jet in one of the three
carbs. Then placed the washer in the carb body to protect the aluminum, then
offered the bolt (threaded end of course) up to the jet, then tapped it down
with a hammer. Do this to the other carb to. Remeasured the jet recession,
reassembled the carbs, and checked the mixture. I had to do this about three
times to get the mixture rich enough. proceed in small incremented as you
don't want to push the jet down to far. If you do, the float bowl will have to
come off to push the jet back up.
Here are the measurements of jet ressesion for my carbs.
1969 Front Stock 0.081"
1969 Rear Stock 0.100"
1968 Carb #1 0.065"
1968 Carb #2 0.058"
First the other two carbs used were adjusted to 0.100" and the mixture
was still to lean.
Finally all carbs were adjusted to 0.153" and it seems to be running
rich enough, but no road test has been done yet as I was going for just a
rough tune.
I hope this helps.
Richard Seaton
RSH17@msn.com<mailto:RSH17@msn.com>
View My restoration @
(http://groups.msn.com/Richards69TR6Restoration<http://groups.msn.com/Richard
s69TR6Restoration>)
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