615cc Big Bore Kit

Ok, I have heard a couple of things. I'm just wanting to know what all is involved in doing the 615cc big bore kit? Will I need to have the cylinders bored at a machine shop or will the pistons fit in or what? Because I noticed the kit does not include cylinders.

Sorry, 1982 GPZ550

Your cylinders will have to be machined for the bigger bore of the pistons.

I sent my cylinders to APE. Bought the 615 kit from them, and am very satisfied with the finished products. Installation is taking a bit longer, because now I'm thinking about rebuilding the bottom end, and sending them the rods and cranks to machine and balance. All done at once, and this engine will last another 45000 miles.

I suppose that someone who was familiar with the 550 would know the manufacturer of a 615cc kit based on the displacement sized the kit gave you... I will take a stab...

You will need to remove your cylinder head and cylinder block and have the block bored. The size of the bore will be the smallest bore possible to achieve the bore to piston clearance proscribed by your factory service manual. This service will cost a couple hundred dollars generally.

You will get pistons, piston rings, piston pins and a means for securing the piston pins inside the connecting rods such as circlips or buttons, etc.

Is is likely that the stock cylinder liners in your 550's block have enough material for boring to this width but I don't know that for sure. Ask the seller of the kit.