No worries about a lengthy reply. It's all good info.

TPS = Throttle position sensor.

As for your crank position sensor error code. I'm sure guys here have had the same fault code with a running bike. I maybe wrong but the fault code for the crank sensor may well be a number, 12. If the garage have cleared the fault code, it really needs to be seen if it is back. Clearing codes doesn't clear a fault. If it is back then it's a simple wiring checking process. The crank position sensor acts like the big drum in a marching band, everything else gets its timing from it, when and how often to inject fuel for example.

You mention your fuel delivery system was dirty. Have you cleaned and checked the integrity of the injector? Sorry if I've missed that.

As for valves. Mmmm? I think only you can answer that question. I know it's a pain but I'd do it myself. It's a simple bike to work on just a pain sometimes.

The XT Yamaha manual used to be downloadable from this site if you subscribed. It has all the tech spec and how-to's.

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