When turning the water on at the kitchen sink, sometimes it comes out fine, other times very slow. The faucet is about 3 years old and brand unknown (just receontly moved in) I can however get full pressure from the sprayer. To fix the problem, I have to turn the water off and on several times. The aerator is clean and I have taken the single handle apart for inspection - no change.

Any thoughts?

When the flow from the spout is low, try hitting the spray off and on a few times and see if flow is better at spout. If so, it sounds like you have a diverter problem. We would need to know brand and model of unit to help fix this, or you could simply get a new fuacet (good excuse to update, right?)