Thread: i have a 2004 yamaha yz 125 and recently i have noticed power loss?

i have a 2004 yamaha yz 125 and have noticed i start to loose power after about the first 10 minutes of the bike running great. not to sure what i need to get to fix, but if you have any ideas please let me know. Thanks

It sounds like it is overheating. Did you buy it used? I had a Suzuki RM 125 that was bored .080 oversize. That left not much metal in the cylinder to dicipate the heat. You may need to replace the jug along with stock size piston and rings.

You may have to replace the piston and rings. It sounds scary and expensive but it is not. Do it yourself for under $100.