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Ok, I have a Crankshaft upgrade query. Im in the process of installing a an ARIAS 856 big bore kit into my '96 YZF750R. I have all the piston side of things sorted now but Im a little worried about the extra power being put through the crank and rods. When I pulled the engine down it was already about to spin a big end and that was with stock ponies. I have sourced another engine to install the upgraded pistons/cylinders which has good bearing surfaces but still Im wondering if I should send the crank away to be cleaned up in some way. Nitrided again? polished? balanced? lightened? Rods also, should I get these polished and balanced and nitrided and all that or what? What do you think? Im pretty hard on engines. lotsa revs and plenty of wheelies which may have been the reason for nearly spinning the big end through lack of oil pick up. Should I mod the pick up somehow too???

History I bought the bike in approx 2000 as my first big bike after only eve having a 1981 gsx250. It was a big step up and a big learning curve. It took a few hits too in the process, mostly low speed slides. Had one front end hit after I ran up the back of a stationary vehicle which gave me an excuse to buy some brand spanking new forks for it as the original ones had started leaking pretty badly anyway. I had spent a year in Japan earlier on so had contacts there that were able to send me a set cheaper than I could have rebuilt the originals. After a few years I started to become quite proficient on it at fast cornering and wheelies but all the thrashing around left it starting to drop out of gears and then eventually changing gears by itself as I would be on the power around a corner at speed. Very nerve racking!!!! I decided that it was time for the big rebuild and what was going to be a 6 month job has stretched out to 3 years. It now has a 2001 R6 tail grafted on to it after much fabrication and welding work. It helps being a welder by trade!! The R6 tail now bolts on as it does on an R6. The subframe assembly was shortened approx 50mm to make everything fit correctly but I think it looks pretty sweet. The Engine is taking a little longer to sort out. I bought all new bearings, seals and everything from the US for it after coming across a second bike while living in Canada. My engine upon dis assembly was a bit of mess and was very close to spinning a big end and spitting me off and the gearbox is going to need all new syncros and probably forks. I have pulled the crank from the newly found engine and it seems to be fine and so now I have all new bearings that suit this crank and case. The head was completely rebuilt with new valves as the originals were warn down to a knife edge and were no longer sealing making it a complete mongrel to start. At 65,000km Im not surprised really though! It had a hard life! I spent hours upon hours cleaning ports after lots of research into the job and will have it all sent off to check my work before closing the engine. Arias 856 Pistons have arrived and the cylinders all prepped for the upgraded capacity. This was quite a process as the Kit does not specify what sleeves to use. After quite a bit of research into different options Ive found the Thunderace 1000cc (75mm I think) cylinders were the best for the job. Only the latter years though from memory. There was a few mm different over the course of production. So sleeves removed from a set of 1000cc cylinders and fitted to my 750 cylinders with the little cup cut outs and all. Machined to 77mm to suit the new pistons and all ready to go. Next thing to sort out is the Crank, Rods and gearbox and I can look at putting it back together!!! Maybe someone can let me know how I can upload pics and I will...