Fading Fazer 400

My son has a 400 Fazer and on saturday he returned to london via m40 and he
said it kept fading (loosing power) from 80 to 60. Conditions were high
humidity are they prone to carburetta icing? Each time it regained power
after a short time.

any ideas

 

Maybe.. Is it an import? Imports don't always have carb heaters, so ice
up during the winter. Mind you, carb heaters aren't a total cure, as my
CG125 has the odd moment when it's very cold out.

 

Yes. Cold and damp.

Sounds like icing to me.

 

Very true. Although my most quirky bike these days, has to be the FZR.
Getting less quirky all the time through molishing the right bits.