Have gradually been increasing the ride distances on the Moto Guzzi, which has resulted in the odd comment about being a "motorcycle widow" from her indoors, a rather dark description if you ask me. Last big ride was a touch over 270km, ostensibly a "poker run" but there was no poker. Quite a few stops. The Guzzi has been very reliable so far but slowly developing a wide flat spot around 4000rpm, made much worse on some of the climbing on that long ride. Once back home, I steeled myself to try to dismantle it a bit to get to the carburettors. I have been rather reluctant to get too far into the Guzzi, it wasn't obvious how the seat or tank are removed. Turns out the seat is just held on by a couple of nuts at the back and snugs under the frame at the front on a couple of tabs. The tank is held on by...an elasticated tie. Something I had been putting off took all of 5 minutes to do. If it was a car I would have guessed the fuel filters were blocked. The previous owners mechanic had unfortunately thrown them both away. The Dellorto carbs are a much simpler thing than a Mikuni - the slide is operated directly by the throttle cable, no fancy throttle plates or vacuum here! It was all a bit mysterious from there. I popped the float bowls off and found no problems, jets were not blocked. The floats themselves didn't match (so somebody rebuilt one carb), the float levels looked a bit ropy on the RH carb so I bent it back to spec. Blew through the jets again, looked at the needle/seats. Didn't find anything else. Pulled the fuel taps off the tank, saw where the fuel filters should be, sighed a bit and blew everything out and re-assembled the tank again. When setting the tank back on I re-routed the throttle cable a bit, it's a split arrangement that looks a bit susceptible to binding if it isn't kept away from the tank down the spine of the frame. Put it together with little confidence I had found the problem but wow, it's a completely different bike. Fatter acceleration than ever and proper throttle response. I'm not 100% sure the problem hasn't been there the whole time, as when I started riding it I barely used the throttle at all. Anyway, the old girl now leaps down the road with that friendly grumble, is no longer popping on the overrun and climbing hills with nary a twist on the throttle. Still not sure what fixed it. Don't care.