That depends on whether the cylinder block is the same as on the 550. I tend to think the holes in the aluminum are smaller so the sleeves are not so thick as they would have to be to put 400cc sleeves into a cylinder block for a 550. However, I could well be wrong.

Remove the head and measure the outside diameter of the sleeves in the block, and I should be able to tell you if it will be a simple matter of boring out the stock cylinder liners for the 615cc kit or if the block would have to have the sleeves pulled, new ones pressed in, and then cutting the cylinders to a proper bore size. I would think it would be cheaper to just get a used cylinder block from the USA if it comes to that.

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| 1990 Kawasaki Zephyr 615 (Daphne) -=- 1986 Kawa Ninja 250 (stolen) |
| The Motorcycle Fuel Injection Handbook -=- http://tinyurl.com/297abo |

Thanks for all the input. I had found the same specs as far as bore and stroke for the 400 vs the 550. I happened across a big bore kit here in Japan that increased the bore to exactly the same as that in the 615cc kit. (Obviously displacement is still down due to the shorter stroke) Unfortunately, that kit required resleeving the 400 block. I'm pretty sure I'm going to go hunting for a 550 setup from the states so I can avoid a lot of undue machining costs and have the longer stroke as well. I'm pretty sure I'll go ahead and get the machine work done in the states as well. It's been a while since I've had any cylinder work done, but I seem to remember it being less than 17000 yen (about 200 bucks) a hole.