Yamaha Xmax 125cc 2006-2009 (58plate) trouble

[Chriscam90]

Hey! So I have a 58 plate xmax that is losing its top speed. It used to go almost 80+mph and then last year it was maxing out at just over 70mph, fast forward to this season and it was maxing at 65, now its not even making that. I have changed the coil/lead, plug, oil filter, oil, and air filter. I’ve checked the air intake and hose and there is no blockage. Could it possibly be a fuel pump/filter issue on that side of things? Really stumped here so any help is appreciated.

[lukeyman]

Have you become less aerodynamic over the same period of time?

[Toma500]

Could be time for a compression test if its lost that much performance ,possible cam wear ? In need of a decoke ? Try some redex through it might help .

[Benni]

Toma500 said:

Could be time for a compression test if its lost that much performance ,possible cam wear ? In need of a decoke ? Try some redex through it might help .

In the same direction : How many miles has the engine run ? Are the valves adjusted manually or hydraulic ? How does the spark plug look like ?

[750turbo]

lukeyman said:

Have you become less aerodynamic over the same period of time?

Sorry but....

[916]

This could be your rollers on your variator, probably worn to create a flat spot, which in turn is not letting the belt open fully.
Have they been replaced recently?

[DanGibsonRacing]

[redacted]

[HairyMaclary]

As above belts and rollers are worn. 80mph lol.