Hunting for a Miss

[Egaeus]

Were the needles adjusted as well when the carb was rejetted?

Have you checked the float height?

Took the needles out, cleaned and inspected them.  That whole assembly seems fine, the rubber bellows at the top of the slides as well.  And yes, the little rubber o-rings under the plastic top hats were replaced with new and are installed.

Float height seems good and the carbs do not belch fuel when the Pingel is left on for days between runnings.

I saw nothing about adjusting the needle height.  That's probably your problem.  I can send you appropriate #4 washers.  Just PM me your address and total height you want to raise the needles.  I think 1-1.5 mm would be appropriate for your setup, but I'm not sure.

[pres589]

I saw nothing about adjusting the needle height.  That's probably your problem.  I can send you appropriate #4 washers.  Just PM me your address and total height you want to raise the needles.  I think 1-1.5 mm would be appropriate for your setup, but I'm not sure.

You're correct, I haven't changed height of the needles.  This always seemed like hack at best.  And I worried about the OD on the washers in play. 

Can you explain exactly why I want to lift the needles?  If there's some real science behind this one I'm all ears.  If this is just another "Throw in more fuel, Suzuki was being overly protective of the petrol when they set these things up" bit then I think I'd rather throw jets at it.  Also, a *good* diagram of how to install the washers would be great, I worry about putting them in the wrong place and botching thigns up.  I *hate* pulling the carbs on this bike.  Hate with a side of dispise.

[Egaeus]

The only reason that it's a "hack" is because Suzuki didn't supply adjustable needles in US bikes.  European bikes have always had them.

As I understand it (and I'm an Electrical Engineer, not Mechanical) the needle-raising "hack" is necessary because you only have 2 jets.  The pilot provides fuel for the lower end of the RPM range, main for the upper.  The problem is that there is a spot about halfway through the RPM range where the pilot can't supply enough fuel, and the venturi effect isn't strong enough to pull sufficient fuel through the main when you crack the throttle open until the airflow catches up.  This causes the bike to hesitate.  This effect is exacerbated by the increased fuel requirements of your setup.

Raising the needle increases the venturi effect at a given throttle position as it provides relatively more surface area for the air to act on the main jet since the tapered needle is raised.  This can not be compensated for by throwing jets at it.  You need to raise the needle.

More knowledgeable people feel free to correct any mistakes.

[pres589]

The only reason that it's a "hack" is because Suzuki didn't supply adjustable needles in US bikes.  European bikes have always had them.

Makes sense, at least at this hour of the evening.  Let me dwell on this and see what other people toss out on the subject.

[Wrecent_Wryder]

dd4

[Egaeus]

Personally, I suggest 3mm /M3 washers as opposed to #4. I know a number of people have had no trouble with #4 washers, but a number have, and the M3 is an exact match (ID + OD) for the stock spacers on my '02.

I have #4 washers that are an appropriate OD.  However, the package I got had washers that won't work as well (2 ODs, WTF?).  I know that the washers I offered will absolutely work in his bike, since it's the same setup as mine.  Money back guarantee.