Lost 10mph from Top Speed

[meegwell]

242x used to get 48-50. Couldnt pass 39 today one person full tank. Nothing really different. RPMs were 7400 each. I have had some water build up in the engine compartment- bilge issue some of you are familiar with. Could this be related? Searching threads I find that its probably not an oil or air intake issue w/ normal RPMs.

boat otherwise runs fine and engines sound normal.

 

[Beachbummer]

Filthy bottom? restricted/ hanging reverse gate? Debris?(Not likely since it happened all day)

With reaching full RPM the issue must be external to the engine. (Pump, impeller, wear ring, boat bottom, etc)

 

[Dave burke]

Are your ballast tanks empty? I once had my center one full without realizing it and that cost me about 5-7 mph

 

[mark_m]

242x used to get 48-50. Couldnt pass 39 today one person full tank. Nothing really different. RPMs were 7400 each. I have had some water build up in the engine compartment- bilge issue some of you are familiar with. Could this be related? Searching threads I find that its probably not an oil or air intake issue w/ normal RPMs.

boat otherwise runs fine and engines sound normal.

You wet slip so you get the scum. I have same thing with my ‘07. I have lost about 10 on the top end of my boat too. Get some oxalic acid (powder and mix it up) from Amazon for cheap, spray it then wipe off the filth. Give it some wax and you’ll be back up to 50 in no time.

 

[elcue]

I read previous post about your bilge and notice you keep in water. If you do not have bottom paint you will build up a lot of crap if in salt or brackish water. That for sure will slow you down add some water weight in the bilge and that might be your problem.

 

[Babin Farms]

Wetslipping will grow algae and let lime & scale attach to your boat and instead of being a smooth hull going through the water your pushing sandpaper through water.

 

[meegwell]

Are your ballast tanks empty? I once had my center one full without realizing it and that cost me about 5-7 mph

yes i did check that. Gonna do some more inspections today.

 

[meegwell]

I read previous post about your bilge and notice you keep in water. If you do not have bottom paint you will build up a lot of crap if in salt or brackish water. That for sure will slow you down add some water weight in the bilge and that might be your problem.

i am fresh water but I don’t doubt there is build-up. Thanks

 

[jdrison]

Any updates on this? Im wondering if this is my problem. I have a 2006 sr210 and it won't go above 35 WOT (close to 9000 rpm on both motors). The prior owners put bottom paint on and the antifouling paint is in pretty rough shape. Looking to have it repainted this fall. Not using antifoul paint since I trailer it.

 

[Julian]

A dirty hull will take off significant top speed and will force a higher rpm to reach any speed (vs clean hull).

When my boat is filthy....top speed is 35mph!!!!!! This is why I bought an airdock!