Belt tension

[mickj]

Thanks for all your replies, I changed the belts last month and only took the bike out yesterday for the first time but after only 3 miles I noticed a "tappety noise" hard to explain so I went back home and stripped the belt covers off and I couldn't see anything wrong although the belts seemed to be at different tensions and I did check them twice before putting everything back together. So today I will re-tension them and try again.
Gasa, I don't ever want to see that in my engine.
Dukedesmo, I did strech them to 6 years before changing them but I'm not sure I would go to 10.