On the carbs, loosen the little doors above the primary metering rods and slide them over enough so you can see the metering rod piston top and tighten the door down to hold them in place(they will come out of the primary jets and may not be suck back into the jets when you start the motor if you don't do this) start the motor up and watch all four pistons, metering rods, if they stay down in nuetral idling then have someone put the trans. in gear, if they stay down idling in gear your good. If they DON"T stay down idling in gear you need to trim the springs under the pistons a little at a time until they do stay down idling in gear Please let us know what you find out I don't think that cam is big enough to cause this type of problem, but it may, depending on what lobe seperation angle the cam is installed at If the pistosn and springs are okay the next thing to do after changing the timing is to try the next size leaner rod on the economy step