Chalk Two!!! Thank you for your reply. I really appreciate it. I love my bike and don't like to feel it so unhappy.

The gearbox was repaired by a Yamaha agent. After I got it back, I took it to a mechanic who I trust more than the local Yamaha agents and asked him to set the valve clearance for me as I had never done this since I started servicing the bike myself. After that, it was the first time I could properly test the bike again and I took a 1000km ride out for a weekend. This is when I noticed the top speed and fuel consumption was way off. I phoned him up when I returned and told him about the problem, and he suggested we look at the fuel pump filters as 86000km is a lot of time to collect dirt. When the bike is in neutral, and being reved, it sounds like it starts struggling from 6000rpm. Almost like the rev limiter is slowly kicking in earlier. I helped him to take the tank off and the pump out, and the filter was beyond dirty. He suggested that I just replace the pump and filter to make sure everything was new and clean. Yamaha wanted to charge me a ridiculous amount, so I googled a bit and found a company with aftermarket pumps.

I got this product -
http://www.fuelperformance.co.za/ind...product_id=653

We made sure the tank is clean on the inside. After he assembled everything, he started the bike and reved it up again, with the same problem from 6000rpm. He then took it to Yamaha to connect it up to the diagnostics system to see if it picked up anything. The throttle was a little bit out (think he said 3% or 3 degrees), they fixed that. Then the system also said the crank sensor was out, but the bike is not supposed to start in that case, so they reset the error. They also did a pressure test on the fuel pump and it was measuring 3.8bars which was apparently above the required pressure.

Now, I'm clearly no mechanic. I know the basic oil change and minor service, and fixed a loose crank nut once. That's it. But from what this mechanic explained to me about the valves and high revs, this problem also sounded to me like a valve problem, but I trusted him as that was the main reason I took the bike there (he only had to do the valves and fresh fork oil). Maybe he didn't set it correctly?

I don't know what TPS is I can ask him at what angle he had it set (if he touched it).

Do you think I should get someone to look and give a second opinion on the valves? Or maybe get in there myself and learn something new. I'm not scared of getting my hands dirty, just sometimes scared I do more damage than good. But I just bought a bigger bike now for the longer trips as I don't think this thumper is going to last me much longer if I carry on putting it through all this stress. So now I will have time to dig in there and explore new areas of the motor and learn new things.

hahaha sorry for this looong detailed reply. But I guess you can give better advice if you have more information Thanks again....