2005 Sportster DI - Engine not revving up right

[Broken_Sportster]

I havent had much problem with this boat until i started it up this year. The first time i took it out i felt it idling slightly rougher than it used to. When i would get above about 10mph the vibration would go away so i didnt pay too much attention to it

I have taken it out probably 4 times now this year. The last time i took it out, it wouldnt pull power at higher RPM consistently. It would take longer to respond to throttle inputs and would not hold steady power. After i noticed this, i came home immediately. It still started up just fine and ran fine at low RPM.

Anyone have an idea of what this could be? I changed spark plugs at end of last season. I have never changed an air filter, but never found a mention of one in the maintenance manual for a part number to replace one either. It defintely seems to be an engine problem and not a propulsion pump issue (at least from my limited knowledge)


Anyone who can help would be much appreciated!

Thanks

(also, anyone know a place that will work on jet boats in the Dallas area (preferably south side, Lewisville is the closest i know of)

 

[Bills86e]

Pull the fuel pump, it could be all rusty or the sock/filter all clogged. Have you noticed any water in the separator filter when you do the pre-ride dump out?

 

[Broken_Sportster]

"Have you noticed any water in the separator filter when you do the pre-ride dump out?"

Not sure what you mean by this. Never done this as part of my pre-ride walkaround.

The maintanance i have done on this is just the basic stuff called outin the service manual (lube driveshaft, change plugs, change out bearings/seals/wearing ring in the jet pump).

I have good knowledge of the theory of engines, but not the true mechanics. I am an engineer, not a mechanic unfortunately.

Thanks for the quick reply =)

 

[Broken_Sportster]

Looked through the Owner's Manual and Service Manual and saw no mention of a separator on this model. Going to check spark plugs right now. Anyone know the gap setting for the plugs off hand? I left my service manual at work

 

[pickle8486]

a low idle vibration that seems to clear up as rpm increases but has a loss of power could be a cylinder not firing, these engines will fire and run off of one cylinder. check spark and fuel pressure. if both check out it could be an injector clogged. just a guess though.