The accel pump adjustment is to compensate for slight differences/wear in the accelerator pump itself and linkage slop .... If I remember from my rebuild kit and Bently manual, the spec on the pump is a certain number of CC's of fuel for a given number of "squirts" with the pump activated thru the throttle linkage. If you get too much total fuel, you adjust it back and vice versa.
The stock main jet on the carb is a little on the lean side; this was part of the first attempts at exhaust emissions reduction on the engine. The stock main is a 127.5 and I replaced it with a 130....much better. Like Mark suggested, another possible cause for the stumbles is a blocked manifold heat riser or one with insufficient flow. If you have a stock muffler (or an aftermarket with the heat riser pigtail) make sure the end of the pigtail is centered in the exhaust outlet (remove the left tip, look into the muffler and you should see the outlet end of the pigtail centered in the opening....if it is cocked slightly, use a big screwdriver to center it... muffler exhaust flow around the end of the pigtail helps draw the heat riser exhaust flow. Check to make sure your center manifold to cylinder head riser rubber couplings are not leaking. Check to make sure your throttle plate bushings are not leaking air (unhook the return spring from the throttle arm and try to move it up and down/fore and aft....anything but the slightest hint of movement means you have worn bushings). mike 73T1 ----- Original Message ----- From: "Eric Larson" <[EMAIL PROTECTED]> To: "vintagevwlist" <[email protected]> Sent: Saturday, May 05, 2007 11:37 Subject: [vintagvw] Carberator Problem? > What does the adjustment on the accel arm of a 34 Pict -3 carb supposed to > do? I assume it makes the accel pump squirt faster when you hit the > throttle? (I have the non-alternator carb that I modified to work.) > Problem is - hesitation. it hesitates after it's warmed up. The hesitation > isn't there when you rev it in neutral. Can you adjust that out with the > accel arm adjustments? Do I need bigger jets? > > I'm also running 33" mud tires, which I'm sure doesn't help things. They > really kill the power. No power off the start, and it hesitates when the > choke turns off. Anything below 2000 rpm is slow. Descent power till about > 3500 rpms, then slow again. Should I try different tires and see if the > flat spot disappears? Or should I adjust the carb some more? I have a set > of Kadrons. Would they help with the tire/power problem? Any ideas are > appreciated. > > Eric > _______________________________________________ > vintagvw site list > [email protected] > http://lists.sjsu.edu/mailman/listinfo/vintagvw > _______________________________________________ vintagvw site list [email protected] http://lists.sjsu.edu/mailman/listinfo/vintagvw
