Need Help? Yamaha 25 HP 2 Stroke

I am having an issue with my Motor where it Sounds great, and Barrel Test great but, only acts like it runs on One cylinder when under a load or wet tested.

I have had the motor tested for Compression- Both Cylinders are equally around 130

I have had a full service done, Carb, Spark Plugs, Timing issues, water Pump etc.

After eliminating above issues I proceeded to change my fuel line which I thought might be the problem. Not the Case.

My next option is that I added a Fuel seperator (Keller Brand) which may be starving the fuel intake. I'm out of options and need any advice as to which direction to go. Could this Fuel seperator be starvng my Fuel intake. Or is a 25 HP too small of an engine to have this added to the fuel line?

Re: Need Help? Yamaha 25 HP 2 Stroke

Hi check the spark it could run on a single cylinder just like mine 15 hp it was running nice at low speed and had no power at high speed it had no spark on top cylinder

Re: Need Help? Yamaha 25 HP 2 Stroke

Check the fuel pressure/vacuum to see if pump is functioning properly.
There is a good thread on the frequently asked question section of the forum about fuel system testing.
Test the spark with a spark tester or check the peak voltages going into the coils to make sure both are in spec.
Is this a single carb model?
It would be best to give the motors model # up front for everyone to know what motor you are talking about