99 Yamaha 200hp looses power during throttle up / oscillates

[birdbrain]

When I apply throttle I notice the engine is slightly weaker than normal. Once I get to about half throttle, the engine looses all power (like someone turned off the motor)... then immediately comes back up to speed, then again looses power. It will continue to oscillate like this. No problems at lower idol speeds. Help before someone chips a tooth

 

[rodbolt]

Re: 99 Yamaha 200hp looses power during throttle up / oscillates

about now a model number would help.

 

[birdbrain]

Re: 99 Yamaha 200hp looses power during throttle up / oscillates

Thanks for the reply. The model number is SX200TXRX
6g6 x 001535
U

 

[Ray Neudecker]

Re: 99 Yamaha 200hp looses power during throttle up / oscillates

Oxy engine. Fuel injected with what sounds like a fuel restriction problem. What service has been done lately on filters, pumps ect?

 

[birdbrain]

Re: 99 Yamaha 200hp looses power during throttle up / oscillates

I install a new water separating filter at the beginning of every season which starts in May here in the NE. I check the fuel filter element in the fuel bulb which is attached to the engine. I also change the spark plugs every year. I have never replaced a fuel pump. This problem happened all of a sudden after I had removed it from the water for some maintenance. I repaird a blown fuse for the cig lighter (I plug a search light into it), and fixed a broken wire to my auto bilge switch. I added about sixty gal of new fuel and a bottle of ring free, which I use about every other fill up. I appreciate your help.