Where did you find a bore gauge that small? I have some calipers that may work but I can't find a bore gauge that small.
What is the allowable tolerance between the rod and crank pin?
Originally Posted by
22Racer
The reason the rod needs to be replaced is because the bushing wears. If you have the backplate off check for slop of the rod on the crank pin. I run longer before changing rods than most, but I use a bore guage to see how much it's worn. The bore guage measures down to .0001 inch.
Most people just change the rods often for piece of mind and Go has reasonable priced rods.
The scratches on the rod and backplate are normal and are not an indicator of rod needing to be replaced. Your motor will be fine for another weekend.
Taking the wrist pin clips off can be a pain at times, It is a good idea to change the clips when you change the rod. Especially on the exhaust side, for some reason if a clip comes out it's usually the exhast side. (I am guessing heat has something to do with it)
Rex