hesitation at 3000 rpms

[Christbiker]

One of my valks just started hesitating or coughing? when cold and only at 3000rpms.  running 6 into 6 pipes but have been for 3 years no other changes other than installed new plugs gapped properly.  Ran a tank with techron and use seafoam on a scheduled basis.  Hesitation is less than a second and usually only once per gear.   Carb synch tested by reliable tech 2500 miles ago with all fine there.  Any advise or suggestions are of course, much appreciated.

Blessings,

Woody

[Michvalk]

First thing I would think of is a vacuum leak. Check the clamps on the carbs, (there are 3 on each carb) and the bolts on the intake. There are also several rubber hoses and some rubber plugs on the intakes. 3000 RPM is pretty close to the overlap on the low speed/high speed jet switch, so could still be crud in the carbs. Wouldn't hurt to run a heaver dose of carb cleaner through. I use a 1/2 can of seafoam to a full tank about every couple of months.