Sportster - lots of power but no go

[Sportster Newbie]

We had our 2006 Sportster 150 out this morning and it ran great. This afternoon, tried to head out and it ran fine up to about half throttle. At that point, it revs up to 8000 rpm and acts like it wants to go but can't.

We picked up seaweed in the past and we tried our usual process of running in reverse, stopping the engine and restarting but no help. It doesn't really act like it usually does when plugged up so I fear this is somethign else.

Any ideas where to start troubleshooting this?

 

[thor7000]

is it supercharged?? If so it sounds like it's slipping

 

[Sportster Newbie]

No - not supercharged.

 

[thor7000]

how does it go out of the hole?? Any cavitation?? Only thing to cause your RPM's to jump like that is if your supercharger is slipping (which you don't have) and the wear ring/impeller cavitating.

 

[Sportster Newbie]

oops...duplicate post....see below.

 

[Sportster Newbie]

Sorry to be such a newbie but I don't know what "caviatation" means. When we accelerate, it is fine until about half throttle and then the engine revs up to 8000 rpm but the boat does not speed up and it kinda shudders like something is holding it back.

 

[pvamax]

Only thing to cause your RPM's to jump like that is if your supercharger is slipping

If the sc clutch slips, it would never see 8000 rpms. Which as we see, is irrelevant since its non sc.

Sorry to be such a newbie but I don't know what "caviatation" means. When we accelerate, it is fine until about half throttle and then the engine revs up to 8000 rpm but the boat does not speed up and it kinda shudders like something is holding it back.

Sounds like there is more junk stuck in the pump. Pull the boat out of the water and clean out the pump from both sides. I've had the "full reverse, kill motor, put in forward" method work once or twice while on the water, but usually it wont get all the weeds and crap out and the boat needs to be pulled to get it fully clean.

 

[Freddie1275]

my challenger was doing something similar to where it would only go about 10 then rev rev really high up after half throttle. it was a bad spark plug causing it

 

[Sportster Newbie]

Turned out to be bucket full of weeds sucked up into the pump.

 

[WaTeRMaNiaC407]

Turned out to be bucket full of weeds sucked up into the pump.

As soon I have any cavitation that I can't clear by turning off the motor, I immediately pull the key, jump off and check the grate by hand. There is no guarantee that just turning off the motor is going to clear any weeds or debris that were picked up so you have to be ready to go for a swim.

The Speedster is much better about it than my Waverunner was, That used to get clogged with weeds all the time.