2007 SX230 HO only hitting 38mph

[WaywardSun]

Just picked up a 2007 sx230 and took it out today for the first time. I was about 1/2 tank two adults and two kids. Clean bottom, new plugs, new gas. I was hitting 10k rpm. Acceleration was fine but couldn’t get it over 39 based off the GPS. I previously had a 2004 sr230 without HO motors and would easily hit 47 mph. I assumed with this being an HO I’d be right around the same. Is there something I’m missing?

 

[Scottintexas]

Condition of your impellers?

 

[WaywardSun]

Everything looked to be in great shape when i greased the housing

 

[Acard7]

Change your spark plugs, easiest thing to rule out.. Other than that check oil level and air filter.

 

[WaywardSun]

Just did a full service. New plugs, oils, and filters. That’s why I’m stumped

 

[Ronnie]

Are the impellers stock? Repitched?

 

[WaywardSun]

Not 100% sure but when i pulled everything apart they looked to be original. I’m not the original owner. And to be honest it doesn’t have any better low end that what im used to with my old sr230

 

[zipper]

Ok, tell me about the oil change. This is a dry sump motor. Where is the oil level on the dip sticks while the engines are off, right now? If the engine has been off for a while, hours, the oil should just be touching the bottom of the dip stick. With these motors You need to check oil level while the engine is running, yes running at idle, or within a few seconds of shutting the motor down. I always checked mine while the engine was running, no spilling with the dry sump. If not comfortable with this, check it a few seconds after shutdown. The oil in the sump leaks down over time and will give you a false reading. Many people overfill their motors not knowing this. Too much oil could be your problem. Is there any residual on the air filter or dripping onto the engine bay sole (floor)?

I would also check the connections of the coils to the spark plugs. Sometimes correct seating gets overlooked which results in a misfire. What RPM's were you able to get out of her? WOT should be 10,200 rpm's for an 07 with HO's.