25 hp yamaha 2 stroke performance problems

[loganlejeune]

I have a 2009 yamaha 25 hp 2 stroke engine. the motor starts and idles fine, but when you get to about half throttle it bogs down and wont take off. It sounds to me like its getting to much gas, but while the throttle is maxed out and the engine is bogging if you pinch off the fuel line it suddenly takes off and runs fine for a few seconds and then boggs again. Ive cleaned the carberator and changed the fuel pump diagram, and adjusted the air intake valves. Anybody have any ideas of what could be wrong?

 

[steelespike]

Re: 25 hp yamaha 2 stroke performance problems

I think you'll get more and better help here in the Yamaha forum.
Sometimes a 2 stroke will rev as the fuel supply runs out.
You might see how it responds to a little choke or squeezing the primer bulb.