2000 225 VMAX OX66

[SkeeterBoy1987]

New member here but i recently purchased a Skeeter boat with the 225 VMAX and lately it acts like it is dropping a cylinder as it reaches peak power. Not sure what it is but when the boat reaches about 67 on the gps i can feel it kinda back off and you can hear a change in sound also and it drops to 63 and sticks there. up until a couple weeks ago i could run 70+...i put new plugs in it a couple days ago and it was back and would run 72ish and today its back to its same thing. I was thinking maybe it could be bad gas but i ran out that gas and put premium in it and its still the same....Thanks in advance guys....

[21XDC]

You need new fuel pump diaphrams and or a new primer bulb. It's starving for gas. Fuel filter possibly.

[SkeeterBoy1987]

i havent even noticed a primer bulb? after reading around it seems like the fuel pumps seem to be a normal problem....i figure if im fixing something i'll do all of it at one time....

[21XDC]

The O2 sensor can sometimes goof up too... Do you run ringfree or seafoam in all of your gas and shock treat it? Cleaning the O2 sensor>>> http://www.boatsetup.com/O2sensor.pdf

[SkeeterBoy1987]

what would a new o2 sensor cost?

[SkeeterBoy1987]

and no i havent ran any ringfree or seafoam...

[21XDC]

You should always run a carbon preventer in your gas. Keeps the 02 sensor clean and the rings from sticking. Adds motor life big time. The yamaha O2 sensor is around $250.00-$300.00 I think... I hear that a GM truck uses the same O2 sensor but you have to clip off the plug ends, solder and wrap them with shrink tube... Not sure if thats a great idea, But I have heard it works just fine for alot cheaper. Take it to an auto parts place and match it up. It's just an oxygen sensor and don't care where it reads.... Just what I have heard...