Lower RPM in the RH rotation engine

[Manuel Martinez]

I have (2) 2004 Yamaha 225 HP Four Stroke engines. They use to go 6000RPM at full open throttle,but now the right engine will get 200-300RPM less than the left one. Both engines start and idle perfectly. There is no misfire or vibration. Can someone please tell me how should I diagnose the problem? Is it possible to do some test without having to plug-in a computer like the Yamaha dealer use to diagnose the engine. THANK YOU!

[boats.net]

Check condition of prop, check throttle cables and linkage for wear.

[Manuel Martinez]

Thanks,i will inepect the prop and check the cable/linkage this weekend. Will let you know the results.

[TownsendsFJR1300]

engine

+1 on the above..

I would also check the throttle linkage on the engine (turned off) and compare it to the other engine and make sure the throttle plates are opening fully (the same amount).