When are you planning on going?
What year is your m3w?
Contact info for m3wservices.com in France just in case....
As soon as the weather forecast predicts one week of sunshine or at least mostly dry weather.
My M3W is from 2016.
Apparently I chose the right timing: I left on Saturday 15.07., returned on Friday 21.07. and had altogether
just 15 minutes of light drizzle.

On my way I had to replace one fuse (instrument light) but needed no other spare parts.

But now my Threewheeler definitely makes some noises that weren't there when I started.
