Jet drive choices

Rabbitdawghunter

Petty Officer 2nd Class
Joined
Jun 20, 2003
Messages
147
I was considering purchasing a jet drive boat to use on the Cape Fear River here in NC. The river is quite rocky when low. It would also be used in the tidal marshes to get to the good flounder fishing and duck hunting. What do you think is the better choice, an inboard jet drive or the outboard or merc sportjet style. The particular boat I was considering is the Wooldridge manufactured in Seattle WA.<br /><br /> http://www.wooldridgeboats.com/default.htm
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: Jet drive choices

None of the above. Jets are way overrated for shalllow water operation. What blows out must suck in. In 3' of water, a V-6 Merc jet can suck a rock the size of a softball off the bottom. The other problem is weeds. Shallow water is almost always choked with weeds. It's a whole lot easier to tilt an outboard or sterndrive to remove the weeds than to clear the intake on a jet. Stick with a prop. :)
 

Reel Poor

Vice Admiral
Joined
Jan 29, 2005
Messages
5,522
Re: Jet drive choices

We have a boat down here thats built in Lousiana called a Go Devil, and man will they go, anywhere.<br /><br />Click here to check em out.
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: Jet drive choices

rdh, to me the biggest benifit would be that there is no prop hanging down to be smashed by a rock whilest navigateing the river. as for weeds and suckin stuff off the bottom. i got a waverunner and i avoid weeds like a plage. i don't want to go swimmin in the weeds to get the weeds that would be all rapped around my impeller. with no way to even touch it. and wbw has a good thought on the low pressure in front of the pump. just think about how much low pressure there is when ya get on it and ya aint moving. man, it's trying to suck up the lake and more. i sucked me up a rock last summer on my ski, is costin me bouts $500 for impeller repair and impeller sleeve replacement from a cavitation burn, i'm thinking was caused by the impeller ding.... it wasn't no softball size rock either....rocks and jetpumps don't mix... <br />one other hazard for jets i think is debris floating on a river. sticks that can be sucked up. i've sucked up a few. so far when they get sucked up i just cavitate real bad as the impeller chews up the debris (hopefully) and finally spits it out. but i always wonder,(fear) what if i suck up a stick that don't want to get chewed up. i'm thinking it wouldn't be any fun to extract.....
 

akriverrat

Chief Petty Officer
Joined
Oct 31, 2002
Messages
588
Re: Jet drive choices

Rabbit,weeds are the bane of jets. rocks big enough to do a hamilton, kodiak, or similar design jet are kept out by the intake grate... unlike jetskis. they were designed for rocks and gravel. if you are buying a wooldridge.. contact them directly for advice. they are very knowledgable and helpful.
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: Jet drive choices

ak, i'm interested in the difference. i know what my waverunner has for keeping rocks out. the grate has 4 bars that will let something in that is just over 3/4". if it gets thru, it will go thru the impeller which has a impeller clearance limit of .024". <br />what does a hamilton or kodiak jet drive have for an intake grate that makes it designed for sucking up rocks and gravel? rocks and gravel in a jet ski usually damage the impeller, leading to cavitation and wearing out the impeller liner. as that happens there is a slow decrease in performance to the point of catistrophic failer, the way i understand it anyways. would that not be true for a big jet too? i'm curious....
 

akriverrat

Chief Petty Officer
Joined
Oct 31, 2002
Messages
588
Re: Jet drive choices

ziggy, this should really be its own thread. 1/2 inch spacing on the grate, stainless impellors, stainless wear ring. the way the water moves through the pump, impellor tip wear doesn't seem to be a big issue. there is a slow decrease in performance but not leading to "catastrophic" failure. take it apart and file mushrooming off leading edges of blades is about it.
 

Ken Cohoe

Recruit
Joined
Feb 6, 2006
Messages
2
Re: Jet drive choices

First off I am a wooldridge fan. I have a 21ft fashioned after a wooldridge alaskan by a local builder. Mine has a Red Line 302 with a hamilton jet. On step in shallow water I may pick up the odd pebble. Nothing to worry about. At slower speeds its a little different. I idle over weed beds all the time, (idle) and have no problems. Touch the throttle and its plugged. The boat is equiped with an eze clean grate to drop the rocks. Jets steer like a drunk at lower rpms. You can get a kicker to get you around your fishing hole once you are there. If you go with an ob buy a tunnel boat, as is Wooldridge. Running a river boat is completely different but fun. email
 

kenimpzoom

Rear Admiral
Joined
Jul 13, 2002
Messages
4,807
Re: Jet drive choices

I run my 90 hp Merc sport jet boat all the time in shallow mud full of oyster shells. If it gets clogged, I just shut off the motor and then start it back up. It clears up pretty fast.<br /><br />I have looked there is no damage that wasnt there before.<br /><br />Ken
 
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