This is being cross-posted for as much feedback as I can get.
My '12 Honda CBR600RR is nearing the end of it’s life at 82,000 miles; there’s minor visible scoring in the nikasil plating in the cylinders, and that’s only going to get worse.
I can get the cylinders replated–assuming that the scoring is no worse than I think it is–for about $800 + the cost of shipping the block, but that would require being able to entirely rebuild the engine on my own. I’d probably want to also regrind the valve seats, replace the valves, piston heads, and def. piston rings if I did that. I’ve already got the cylinder head off because the valves weren’t holding pressure.
I can get a replacement engine for around $1500-2500. I can replace an engine on my own, although it’s a pain in the ass.
Or, I can get a new bike. But I’m not sure what makes and models for my riding style will have any better longevity than my CBR600RR has had.
My current short-list is a crashed '07- '12 CBR600RR (because I can easily swap necessary parts/bodywork, etc.), or a Yamaha YZF R6, Suzuki GSX R750, or Triumph Speed Triple 1050 (which is prone to electrical issues, and also needs some creative headlight adjustment to work with clip-on bars). Does anyone have experience with the YZF R6, GSX R750, or Speed Triple? Any issues to watch out for that might prevent any of them from making it to 100k miles without major mechanical work?
A guy that claimed to be very familiar with that engine indicated that the problem is the design of the piston heads. He said that they have very short skirts, and as the rings wear, the piston head twists and pushes the skirt into the wall, causing the wear lines I’m seeing. The solution–once/if I can get the cylinders re-plated–is to replace the pistons with something like Wiseco. Or if I need to replace the entire engine (because you can’t just replace the top of the crankcase, it has to be replaced as a complete unit), then do the same to prevent it from happening.
If your engine is substantially identical to mine, then you might see the same wear pattern in the cylinders with a borescope.
Also, FWIW, I called a place near me that was suggested for machining services (they actually send crankcases out for replating), and when he heard the mileage, he was surprised that I’d put that many miles on it. I guess most people just don’t put that kind of mileage on motorcycles. :\