Idle speed went up 300 RPM why? and pics of my trim tab

[georgevazquez]

I just finished in stalling my lenco 12x18 trim tabs on my 21se with a 225 yamaha 4 stroke. I also changed the impeller, oil, lower unit oil, gas filter (both the one on the engine and the bigger exterior one) My engine always idled at 600 rpm but now it at 900. Not sure why any ideas? could this be because of the new impeller? I also added some pics of the new trim tabs and referb
tilt/trim system