So bought this assured low mileage ex-hire earlier this year and finding the motor is somewhat uneven and whirrs quite bit on the steep hills around here. Also overheated once or twice on severe pulls- to the point of power light flashing so I have to pause for a few minutes.

Mainly the motor assistance sometimes seems to 'catch' i.e. just pause momentarily [i'm not changing gear at this point] and has rotation related whirr which is absent when peddling with power off so when I thought it might be the chain rubbing/rattling; seems not - also have checked chain for stretch- absent.

 

I am somewhat at a loss, this quite good climber may be sub-par performing. Any comments please?

Well thankee all, I seem to have the forum stumped...BUT i think I have fixed the problem and i.e. can now answer my own query. Brilliant!.

Some '3-in-One High Performance lubricant with PTFE' [what a range of lubricants they nowadays do at Halfords] applied to chain, cogs and left to seep into main crank has improved the smoothness of the drive no end, a result so far as I'm concerned.

Moral of the story; do not assume the guy who had the bike before and reported they'd had it serviced regularly .. [b.s etc] ...