Hi Peter, You can play with the revs by turning the vacuum pickup on the cowl while the mower is running full throttle. Leave the vacuum line connected and push the black plastic part inwards and twist at the same time. This will adjust the pickup relative to the flywheel and ultimately alter the vacuum and hence the RPMs.Try this first as i'm almost certain this will alter your revs BUT if it doesnt help try another carby off a mower that you know doesnt rev its head off. You might find that the different governor spring plays a big part in the way it revs. Victa make different colored springs for different rev ranges, but, with time the color wears off and they all look the same, so swapping a few around sometimes help, although this is mainly on the power torques as they have no adjustment on the vacuum pickup.
Let us know how you go.
