Engine Hesitation from O-320, Warrior 1976. A&P advises, annual done, solution provided.

Q When throttling back in Warrior PA-18-151 from full or cruise at 2450 rpm to 2300 I get a very brief (less than a second) engine hesitation. It’s like a little bubble. Then all resumes to normal. And it is not an every-flight occurrence. It kind of gets your attention.

All looks good under the cowl so any ideas or knowledge of why would be great. Annual in 2 weeks but I would like any input on what to look for. I run Fine Wire Plugs and Mags are newly rebuilt. 1404 TT on AF and Engine.

Wes Yockey