Jet boat won't accelerate

[nobodyfresh]

I have a 95 Sea Rayder F16 with a 120hp Mercury Sport Jet. The boat ran great all summer and now has a problem. I was riding around in it perfectly fine and then idled for about 20 minutes in the water. After that it would not accelerate past 1.8mph. It took me 2 hours to get back to the dock that day!

I pulled the boat out of the water and removed a ton of seaweed stuck in the intake grate. I took a real good look at the impeller and it appeared OK with nothing stuck in or around it.

Then I put the boat back in the water and now it hits about 8mph.

I know this isn't an engine problem because the boat hits 5300rpm easily and sounds fine. The boat usually goes about 38mph when running OK.

Thoughts?

[boatermike]

more sea weed is in there? or possible damage i guess but i would make sure the weeds are all gone

[nobodyfresh]

All the seaweed is definitely out of there. I even power washed off all the slime around the area.

[MRNOITALL]

I don't knoiw much But It sounds like the impeller is slipping on the shaft.JIM

[Darkside's Calling]

Open the impeller bowl, all it takes is one rock, piece of wood, or other disturbance and the pump goes to near 0 flow.

I'd bet dollars to donuts that there's still somthing in there, or as MRNOITALL said, sheared keyway

[Regatta Sportivo]

Mine just did the same thing I sucked up some grass and rocks I hope you did'nt do what I did knocked 4 fins off several small rocks were inside 500 bucks later I have parts in route I bet you have something stuck in there best of luck Randy

[divemaster]

I have a 1982 Sleekcraft boat with a 454 chevy and I'm looking for a place diverter for my Berkley 12jc. I will need all the cables and shifter since My boat has never had one on it.

Call me 860-559-9817

Thanks

Bill

[01 ofew]

^^^^hijacked^^^^^^^

[Danger731]

^ omg x2 , worst I've ever seen !

[Danger731]

Any ways I saw a guy last week, seeweed, same problem. Never figured it out in the water. Did you pull the grate and REALLY look around ?

[rockdamage]

You have seaweed blocking the stator. It's what straitens the water before it leaves the snout. I have some parts!

[donmac]

check the gear oil for metal.

[Choppme]

I have a 76 kurtis w/ a panther jet, just idled in some mud...now the boat doesn't accelerate OR suck water for the engine. Overheated quick. I dropped the lower unit, no rocks, no mud, looked fine. I hooked up the hose and flushed the water system, no problems there. I THINK THE BLADE IS SLIPPING ON THE SHAFT. But, when I turn the engine by hand, the blades turn.....now I'm gonna try and turn the engine while holding the blades? See if it slips.

OK, removed the lower unit, pulled the impeller, checked the expanded view housing diagrams at pantherjet.com and the key was in tact, no problems. I'm not sure what happened or what's wrong, but I'm thinking that for some reason the water flow wasn't right?

The shaft from the impeller/key area is the same shaft that goes into the u-joint at the engine...and it's all in tact. That means the impeller WAS SPINNING, but not producing the flow it should have.

I'm taking this beast out and will report on what happens...

OK, the bitch ran like a beast!! I can only say this...IF your shear key from spindle to impeller isn't sheared, then the prop is turning. If the impeller is turning, then the water is sucking IF 1. you have a clear path of water flow and 2. your prop isn't bent up (mine was) or blocked by anything.

Jets work like a pump. The "suction" of the water depends on the path and the impeller. If the grate or impeller are blocked, game over. The inside of the housing can also be "pitted" from rock damage and when you have too much OPEN area around the blades (notice how close they are to the housing) you get NO ACCELERATION!!!

Long story short, clean it out and check your shear key and blade tips. Later!