Yamaha Vity Top speed decreasing gradually year by year.

Hi. Does anybody have any ideas why the top speed is getting lower year by year. I have had the bike from new and when I first got it and for a while the top speed was 62 mph, last year was about 60mph and now I am down to a top speed of 58 mph!!! At this rate in 10 years I won't be able stay at the speed limit. The bike averages about 7,000 miles per year and is currently at 12k miles.

Thanks

 

Re: Yamaha Vity Top speed decreasing gradually year by yea

General wear and tear, decrease of compression due to rings being worn, belt slipping, worn rolelrs etc etc.
Simplest option, give it a over haul. If you think the amount of usage warrants a bit of money spent on it then why not eh