Fuel probs?

[MikeL]

My 650(26k) freshly serviced has just developed a stutter around the 3500/4000 rpm mark just as i accelerate in 1st /2nd gear which makes it feel like it needs to go onto reserve but the tank is full. Any suggestions as to the prob?
thx

 

[wedgie]

mine did a simlar thing (94 funduro)
would run ok up to 90 mph 2s up
and then start to cut out like running out of go juice
fuel stavation?
blew through the tank breather pipe after a poping sound
of the breather clearing had no problems since