Hesitation / intermittent power loss

[f@-pots]

Hi guys.
I've thought for some time that the grin factor wasn't as much as it used to be, but put it down to 'getting used to it'however lately I've noticed a hesitancy when accelerating and during a hoon with a wee tin top it was hard work keeping up.Last night after a thirty mile stint down the A1 I turned off onto quiet roads and gave it some beans this time holding it in third. Pretty uninspiring and hesitant up to about 5000 rpm then all of a sudden 'whump' in came the power I'd been missing for all this time ! Unfortunately it disappeared all to quickly when I changed up and could not always be replicated. My gut feeling is advance and retard sticking / leaking / f****d !
Any ideas would be gratefully accepted.
Nick...........

[Jonny_b]

Intermitent faults are the worst. That said, My Chim had a similar problem turned out be a knackered fuel pump. Did it smell of petrol when it hesitated?

[Barreti]

I've seen a Chim do something similar. Try changing the rotor arm, his was FUBAR'd although it didn't look like it at first glance.

[HRG]

Have you refuelled recently? Seems to be a lot of duff fuel about.

[f@-pots]

I'm going to investigate all that lot , one thing I forgot to mention was cutting out when going round bends quickish'. Usually on a low fuel load but the other day it did it on over a quarter tank so maybe I've got a fuel pick up problem?