I have 2000 H2X 7.4 MPI and it has the captains call exhaust. I have noticed the last 2 days that the sound is partialy muffled with the exhaust open. When I hit the switch to close the exhaust is gets quieter then when I hit the switch again it is back to normal loud as it ever was. What would cause it to get patialy muffled during use?? Could this cause any water to get in any wrong places (ie. cylinders) ??

Check to make sure both of your solenoids on the diverters are working, i had the same thing before when i first bought my 252. one of the solenoids was bad and would close after a few seconds diverting half the exhaust back underwater. if thats the problem you can order a new solenoid for about $80.00 just look at our old ones to determine if its a three or four wire.

I'm 99% sure you'll have the 4 wire system.

Like Bigred said, watch the solenoid and see what it's doing when you flip the switch. If nothing at all, check power to it. If it switches open, then closes right away it could be a bad solenoid or it could be out of alignment. There is an adjustment screw on the back of it and it can be sensitive.

I had one that was showing 12 volts, but didn't have the "jump" in volts to pull it into the open position. In the 4 wire harness there is a cylinder called a Power Commander that provides the extra juice for switching.

Mine turned out to be a bad ground.

Thanks guys for your help.