Power loss in the wet

The mystery deepens. Thanks to wet-weekend Bertha, there's been plenty of near side puddle action to play with today. I've noticed that I may not be losing power at all, and what seems to be happening is the tone of the engine is changing.

Almost immediately on splashing through a near side puddle, the 'high' tones of the engine get a lot louder, making it sound a lot 'puffier'....

I'm going for a clamber round the underneath tomorrow to look for a hole in the exhaust or something.

Sounds like a result! Funny how you can get a bit paranoid about noises - and there are lots of them on these old girls. I've convinced myself that I need a new gearbox after hearing a thrumming sound when cruising at 50 on long trips. It's probably just wind in the bodywork

Ahhh the thrumming, yes I think I have about 3 of those, all with separate conditions to cause the thrum.