Money, lots of money and patience, lots of patience and time, lots of time. You can't use stock parts and gain serious hp. Having been a hotrodder since the mid 60s you have to spend serious $$ to get serious hp. Anything that could be done for performance gains was done to this motor. I blew up a couple in the process but found my mistakes and started over. This time, I used 92 cases and crank. The crank was sent to Falicon for their supercrank treatment. It's been lightened, polished, oil holes chamfered, shotpeened, nitrited, etc. After all the piston work was completed, the rotating mass weights of the pistons, rods, rings, bearings were sent to Falicon so it could be balanced correctly. I use Carrillo rods and Total Seal gapless rings. The head was one of the more expensive pieces. We took out the valve guides and seats, matched the combustion chambers with the new bore (79mm) and then relocated the guides and seats for oversized valves. The head was filled and re-ported for optimum flow. Since the valve spacing changed, so did the cam spacing and the rocker arm spacing. Had to have custom ground cams to match the new valve spacing and machine new stuff for the rocker arms. Had to make a new shaft for the carbs to match the new intake spacing. Finally, had to machine the piston crowns to match the combustion chambers/valve setup. From what I can remember a good Yosh 750 superbike motor made about145hp but this decreased as the oil heated up, the motor got hotter, etc. The head flowed about 230-240 or so. My head flows 330+. The shop who did the head work and piston work was Franx Machine Worx. Unfortunately, Frank is no longer in this business. He sold out in the late 90s and went to work for GM Performance Parts. This engine took about 6 months to get done. There are no bolts in the cases, only studs/nuts. I can service the valve train with the engine still in the frame. I don't spin the motor much past 12000, although it's good to 14000. Just no need anymore. I did the 750 motor since it's smaller than the 1100. On the Mag IVs that run 1100 or bigger motors, the motor must be lowered to get the valve cover out while the 750's size lets the valve cover slide right out. Having said all of that, I'm going to build a Bandit 1200 motor later this year for the bucket of S**t. I'm going with a 1340 setup, serious crank and head work and fuel injection. Gotta make a new tank
to fit the fuel pump, injectors from a Yamaha YZF or GSXR1000 on Kinsler manifolds,etc. Have to make stuff for the crank sensor, cam sensor, trigger wheel, etc but that should be relatively easy to do (maybe). The hard part will be the electronics/programs but think I have that figured out. It's stupid to do as I could just go buy a Gixxer 1000 but then I'd be like everyone else and have a Gixxer 1000. I like being different. It keeps me totally occupied and thinking out of the box but most importantly, keeps me out of the Mrs hair.:cheers