Originally Posted by c14aff

Hi all.

I have a 53 plate st170 that has now covered 78k.

All has been well but of late noticed it's abit lumpy on idle, but clears if i raise the rpm slighty.

I also notice at 2500 rpm it feels if it's slighty holding back underway, but again if you put your foot down it clears.

Any idea's?????

Thanks

Dan