the nephews both have Beta Evo 125's 2015 models one of them seems to be lacking in power compared to the other one and also sounding a little tinny i'm thinking new piston rings and top end bearing would help any advice would be much appreciated

A couple of days ago I  found a video on YouTube covering the same thing. (The things you have to do on lockdown!) Search for "This Old Tony"  its title is Top End Rebuild (2 Stroke) Its quite informative and certainly humorous.

If it is sounding tinny, maybe it is running a leaner setting in the carb? It might be worth checking what’s in each carb before opening up the motor?

Possibly in need of a silencer repack. Tinny sound and deterioration in response can result from original packing being clogged/burnt away.

Ive repacked the silencer end and it's slightly better but i'm guessing there is packing in the mid section which isn't so easy to do as it needs cut open re packed and re welded.

Also tonight i looked at the cab settings online and noted that the air screw setting is 1 +1/2 out from closed I'm sure when i cleaned it out the other week there for the nephew it was 3 turns out ! Guessing he's been possible fiddling around with it although he would deny it ?? will check tomorrow hopefully it's that simple don't want to get into packing the mid box if i can help it

Edited April 29, 20206 yr by austin6728