Vibration Shutter on Take Off

[Green Hornet]

The last few flights the aircraft has been exhibiting a vibration from either the engine or prop on take off.
I have tried different TO techniques but it is somewhat intermittent. Some times slight to moderate vibration type shutter and sometimes no shutter at all.
I was thinking it was something I was doing wrong like TO to early so I extended my TO on the ground but it continues to happen to some degree.
I have an annual coming up so is there anything I should be looking for like bolts or do you think it is poor TO's. Something is wrong my gut says it is the airplane but I always question my flying technique?????

[maules.com]

First things that I would check.
Out of round, or balance, tyres shakeing the landing gear.
Loose engine mount to fuselage bolts which need regular torque setting as they go through multiple layers of different substances,
Prop not cycleing to flat pitch properly, caused by governer, poor crankshaft oil port alignment.
Loose or improperly mounted cowlings.

[Green Hornet]

Hey Jeremy,
Now that you mention it upon reflection it might just be the tires? that never occured to me ! the engine and the prop have been excellent. I'll try the brakes after I am airborne.
Thanks

[Wayne]

Most likely a flat spot on a tire as Jeremy said. we just had a new airplane owner the other day saying somethimg must be wrong with his right main gear LOL. It was just a big old flat spot.

[Green Hornet]

I am some what reticent to admit this but Jeremy et/al were correct. I checked the tires this morning and they were in dire need of air (FLATSPOT?). I got them correctly inflated and taxied around a while. Then the first TO with absolutely no vibration shutter.
Problem solved!
Thanks everyone!
Bill