First off, I am not a mechanic, but I know a guy that builds some pretty extreme stuff for pro hill climbers (bike and sled). He's great with engines and building what people want. He just finished stuffing a turbocharged YZF1000 motor into a Polaris Razor. So, I will not be doing this work, but will be providing all the parts for the build to a very competent builder. What I want to know is if anyone has done this or knows someone who has done this. Here is the plan..... My 96 XR400 is in dire need of a complete motor rebuild. I have also been wanting to do an e-start to the machine using the trx400ex parts. I love my XR, it has become a part of me over the years, but I am almost 47 with 3 knee surgeries to the kickstarter knee and would love the option of the magic button. Thanks to e-bay I have all the e-start parts except the actual starter motor and the 400ex crank . I have a stage 2 hotcam in it already and a BSR-42 carb. I want to redo the head with oversize Kibblewhite valves, and punch the cylinder out to a 440 since I will have to split the cases for the 400ex crank anyway. I have recently found out that HotRods makes a stroker crank for the 400ex, which, for about $240 more, would take the motor up to 460cc (insert Tim the Toolman grunt here). Has anyone done this? Is it going to seriously compromise the motor to do this to it? I don't ride in a hot area, and I ride at elevation most of the time in technical terrain where luggability (if that is even a word) is key to my riding style. There are times however when things really open up in some of the high mountain prairies, and you want to have the power to open it up and go . I'm just looking for a little feedback before I start this project. It will probably be strung out between now and next spring, but I want to get started getting parts together now as I can afford it, and have the work done over the winter months. Thanks for any feedback guys. My main decision at this point is to stay with a 440cc big bore, or stroke it out to 460cc. Any other opinions about upgraded CDI boxes, starter motors, wanting to come ride it when it's done, are always welcome.