Runs on three after sitting for a while

[s7paul]

Hi all,

My bike doesn't get used very often, and I'm finding that when I start it after it's been sat in the garage for a few weeks that one cylinder (no. 2) doesn't fire regularly until the bike's been running for a while.  Once it's all warmed up everything seems fine.  And ideas what might be causing it?

Cheers,

Paul

[matthewmosse]

Check plug leads and dose the fuel with redex carb cleaner as a start.