Gary,
IMHO ........
Those are probably "Factory" needles .. they are very steep ... and I
assume Mikuni 157 mains. What you have described indicates that your
pilot circuit is entirely too lean. You have the right needle setting
at the second clip position ... twisting the crank at lower - mid RPMs
.. is OK ... this is a needle job function, (the cruise and deaccel is
a pilot job so lets forget about that for a minuet). When you move the
needle out one more click you are too rich when you crank on the
throttle because they are letting too much fuel in and you bog ... So
you have proven that the second clip position is as rich as you can go
without a bog .. and the needles are a done deal. If you change your
main jet you will have to find the correct needle position "again" ..
so unless it is falling on it's face at 7500 RPM .. (you said it
wasn't ), leave that alone for now. If you want to fine tune a half
click with a washer .. do it after the pilots are in the ball park ...
OK .. now the pilots ....... or course they run the idle with a fine
adjustment via the screw .. and they run everything else on light
throttle cruising .. unless you crack the throttle enough to make the
slides move. Things were better down there when you moved the needles
to a richer position .. but that was cheating ... that is called
"false idle" where you move the needles out far enough to let an
excessive amount of fuel sneak past when the slides are closed ... it
helps the pilots out but you pay big time because now you have made
the needles too rich when they try to do their thing ... .
You are getting away at idle because you have opened the screws enough
to compensate .. but when you try to cruise or decelerate .. you are
too lean ... So you have completely isolated your problem.
If these guys have really been blown out good ... then you can do a
couple of things to richen your pilot mixture, (and when you do you
will have to turn those mixture screws back in a little so you won't
be too rich at idle). One thing you can do is put a larger pilot fuel
jet in .. like one of those 42.5s that have been being discussed
lately. The other thing you can do .. is replace the primary or
secondary pilot air jet with a smaller jet, (less air will make it
richer). The easiest to change is the PAJ2 .. which is behind the
slide rubber at the 1 o'clock position ... and it probably has the
stock MK170 in it ... see what you have laying around .. if you have a
DJ160 or DJ150 still in the box from an old Stage 1 installation ..
put one of them in ... both are smaller than the MK170 .. The Mikuni
jets have their emblem on them ... and a MK 170 is a whole lot bigger
than a DJ 170 so make sure what you have, (if you have your old stock
main jets .. the MK 152.5s put them in .. they are almost a match to a
DJ 160 ... but if you really have an old DJ150 set .. put them in for
sure). I assure you this will improve your problem properly .. and I
suspect you might want to bump up the size of the pilot fuel jet
anyhow to a 40 or a 42.5 .. but they are not easy to get .. and you
have to wait for a piece of brass to give birth before they show up in
the mail ... Where as the regular MK or DJ jets are easy to get
quickly and will probably get you very close to where you want to be.
Once .. you get the pilot circuits exactly where you want them .. you
may have to move your needles in a 1/2 clip position, (since the bike
at cruise will be running on what ever the pilots are contributing
plus what is sneaking around the needle ... If you don't start bogging
again then you are OK ... If you do .. the put the washer in and do a
1 1/2 on the needle instead of a 2 .......
This isn't hard stuff to do .. but you just have to make sure you
don't cheat to make one thing OK .. cause it will get you on the other
end and make you crazy. Honest !!
Good luck ...
campbell
----- Original Message -----
From: "Gary Rathbun" <[EMAIL PROTECTED]>
Subject: TourMaster Carburetor Questions
>
> Calling all carburetor gurus! I'm having problems
> snip <
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