New boat help needed. Pump slipping on take off!

[fishbum]

Hi guy's I'm new here, not new to jets but have one I can't get to work right!
I just had a new boat built by James River Jets
And bought a older merc v6 from him.
The boat is heavy it's an 1866 heavy aluminum rod boxes, decks ect.
Has a tunnel now the issue. When I take off I get a good bit of slip with the impeller.
Then it will grab an be ok. I have moved the motor up, down, out and up just about everything and not much change. Boat feels front heavy to me but floats level and only about 5-6" draft.
Console is up front, Was just told this happens sometimes with heavy boat and high hp motor. Motor has the power to break the impeller loose before the boat moves good.
My motor is a older 200 i think it should have the larger pump sp200
But it is the standard v6 any help would maybe save a life!!
Looking for the razor blades now. Thanks

 

[Buddychrist]

Could you get a bigger intake grate allowing more water to flow into the impeller? I had a racing intake grate on my jet ski and it made a world of difference

 

[Lil' Blue Rude]

Might not have the right size impeller. Or the impeller could have enough of the blade removed from repeated sharpenings. How many rpms are you turning?

 

[fishbum]

Might not have the right size impeller. Or the impeller could have enough of the blade removed from repeated sharpenings. How many rpms are you turning?

Hello, the impeller is correct for the pump and is like new as is the liner
Don't have a tach yet. Impeller is 7 3/8 v6
The larger pump they sell for the 200 is 7 5/8 with a larger volute and intake
Not sure of that thing with the big hp with the heavy boat but sounds interesting

 

[Buddychrist]

I was turning 5500 max before I traded my jet ski for the jon boat

I actually have two 750cc jet ski engines I'm trying to sell, they need full rebuilds but maybe someone would be interested in them for a jet drive Jon boat conversion

 

[Lil' Blue Rude]

Don't you just have to switch the shoe and liner then you can run the 7 5/8impeller? Not real well versed in the bigger motors. But if it's pullin past 6000rpm on top I'd say it needs the bigger impeller.

 

[fishbum]

Don't you just have to switch the shoe and liner then you can run the 7 5/8impeller? Not real well versed in the bigger motors. But if it's pullin past 6000rpm on top I'd say it needs the bigger impeller.

No everything except the driveshaft is different
The volute, intake, liner, and impeller
Might try to sell the v6 unit then buy the larger one or sell the motor and row the darn thing

 

[Buddychrist]

Put a jet ski engine in it, cheap, easy to maintain, and has plenty of power

 

[fishbum]

Put a jet ski engine in it, cheap, easy to maintain, and has plenty of power

Have seen a few of those seams like the motors don't last
And the pumps aren't anything like sport jet or other inboards
I have seen some that they leave the bottom shell
On the motor and glass it into the hull
The way you said that I'm guessing that is what you have?

 

[Buddychrist]

I have a 25hp outboard. I traded my jet ski for the Jon boat, I have too much of a spinal injury to worry about going fast, I just like to fish

 

[fishbum]

Got it! The impeller needed 4 shims to make it right. What a difference!
I had just looked not checked with gage
Thanks for help!