tinker with

tinker with

Try to repair, work aimlessly or unskillfully with, as in He tinkered with the engine all day but it still wouldn't start. This idiom, first recorded in 1658, alludes to working as a tinker, that is, mending metal utensils.
See also: tinker

tinker with

v.
To make unskilled or experimental efforts at repairing or improving something: I tinkered with the engine, hoping to discover the trouble.
See also: tinker
References in classic literature ?
He was too low to do anything but land, and that immediately, while he had the more open country accessible, for directly east of him was a vast forest into which a stalled engine could only have plunged him to certain injury and probable death; and so he came down in the meadowland near the winding river and there started to tinker with his motor.
When the ECHO presented Mr Tinker with a copy of the document, he said "that has got nothing to do with me".
I'm not afraid to get under the hood or under the car and tinker with it.
I would tinker with my toys and try to make them go faster; I guess that just built up to cars.
I think eventually it will get to something where they don't have to tinker with it anymore and, to me, that's a playoff system and that's not going to happen.