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Building a dredge using a jet ski motor n pump - ?????

Jd		Posted : Thursday, 12 September 2013 12:53:49 AM(UTC)
Rank: Gold Nugget Medals: Groups: Registered Joined: 5/07/2012(UTC) Posts: 99 Location: Blenhim Thanks: 114 times Was thanked: 19 time(s) in 13 post(s)		Has anyone on here ever tried a jet ski motor and pump on a dredge would it work and what size dredge would it run???? I have an older jet ski from my teen age boy but he has never used it so what do you think ?????
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gogold		Posted : Thursday, 12 September 2013 9:35:05 AM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 5/01/2012(UTC) Posts: 217 Location: gore Thanks: 4 times Was thanked: 56 time(s) in 45 post(s)		would probably be fairly thirsty and cost too much to run? would probably make 1 hell of a dredge tho maybe run an 8 inch?

Jd		Posted : Thursday, 12 September 2013 11:08:51 AM(UTC)
Rank: Gold Nugget Medals: Groups: Registered Joined: 5/07/2012(UTC) Posts: 99 Location: Blenhim Thanks: 114 times Was thanked: 19 time(s) in 13 post(s)		Originally Posted by: gogold would probably be fairly thirsty and cost too much to run? would probably make 1 hell of a dredge tho maybe run an 8 inch? That's what I was quietly thinking
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Jd		Posted : Thursday, 12 September 2013 11:10:48 AM(UTC)
Rank: Gold Nugget Medals: Groups: Registered Joined: 5/07/2012(UTC) Posts: 99 Location: Blenhim Thanks: 114 times Was thanked: 19 time(s) in 13 post(s)		maybe change the motor to a small diesel 30 plus hp should do it what do you think
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gogold		Posted : Thursday, 12 September 2013 12:13:54 PM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 5/01/2012(UTC) Posts: 217 Location: gore Thanks: 4 times Was thanked: 56 time(s) in 45 post(s)		could possibly work 30hp may be underpowered considering most jetski engines are 60-120hp. if they were good to use on dredges then you would see them on a lot of dredges I think you would be better to go with a centrifugal pump one that's designed for dredging keene, proline etc your dredge will run better as it will have the right pressure-volume ratio. how big of a dredge you planning on building? if you want to go as big as 8inch theres at least 1 member on here that's built 1 that can offer you some advice.

nafcd		Posted : Thursday, 12 September 2013 1:42:12 PM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 28/12/2012(UTC) Posts: 276 Location: ashburton Thanks: 8 times Was thanked: 46 time(s) in 34 post(s)		I would think a jet would have way to much flow unless you took the nozzle off. then you might as well use a centrifugal pump and smaller motor.

Jd		Posted : Thursday, 12 September 2013 3:00:17 PM(UTC)
Rank: Gold Nugget Medals: Groups: Registered Joined: 5/07/2012(UTC) Posts: 99 Location: Blenhim Thanks: 114 times Was thanked: 19 time(s) in 13 post(s)		I already own the ski sitting on a trailer and its like new although it has been sitting for a number of years I was thinking an 8 inch dredge would need two larger motors that would chew threw the fuel I was thinking the ski motor and pump would also chew threw the fuel so It wouldn't save much by changing the motor I was thinking 6 to 8 inch dredge I have been researching the Keene set up the larger Keene pump is about $1500 plus so as I already have the ski I was going to try that 1st I was hopping some one may have already been down this track
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andy		Posted : Thursday, 12 September 2013 5:53:31 PM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 13/12/2012(UTC) Posts: 471 Location: ngongotaha rotorua Thanks: 70 times Was thanked: 88 time(s) in 72 post(s)		cant hurt trying mate!
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trigger		Posted : Friday, 13 September 2013 3:06:14 PM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 13/02/2011(UTC) Posts: 142 Location: marlborough Thanks: 12 times Was thanked: 25 time(s) in 21 post(s)		hi jd I see how you've got the idea . One thing I would look at is the design of the dredge the best way for set up as its going to need a drive shaft . And also aid the jet unit is capable of holding high pressure but would be an awesome dredge

Jd		Posted : Friday, 13 September 2013 3:50:13 PM(UTC)
Rank: Gold Nugget Medals: Groups: Registered Joined: 5/07/2012(UTC) Posts: 99 Location: Blenhim Thanks: 114 times Was thanked: 19 time(s) in 13 post(s)		Thanks mate yes I have had some great feed back on this I now have to decided do I reck the ski for a dredge.... its all looking like a go at this stage although I have also had another option too I was thinking of using the motor and pump in a jet boat dingy as a toy would be great finding gold in the upper reaches of the river 1500 pump and motor may be a plan and continue with the 8 inch
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NUGGY		Posted : Saturday, 14 September 2013 2:06:19 AM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 20/07/2012(UTC) Posts: 267 Location: greymouth Thanks: 85 times Was thanked: 76 time(s) in 58 post(s)		Yep, go with the jet dingy idea. The jetski motor/pump unit would produce way too much water for anything but a huge dredge at anything much over idling, and 2 strokes don't like to idle, they tend to carbon up if not revved. 60 hp would in theory, run two 8 inch dredges! There was a guy building 10 foot hulls just for this purpose, selling on Trade Me about 4k - good value really. The jet dingy would get me into all kinds of adventures/troubles - would love one lol. NUGGY

FossickFester		Posted : Tuesday, 24 September 2013 10:58:26 AM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 14/09/2013(UTC) Posts: 174 Location: Tasman Thanks: 63 times Was thanked: 35 time(s) in 31 post(s)		Why not just sell the jet ski and put the money towards a dredge? It may not get ya all the money needed but surely but a dent the amount...

FossickFester		Posted : Tuesday, 24 September 2013 10:59:27 AM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 14/09/2013(UTC) Posts: 174 Location: Tasman Thanks: 63 times Was thanked: 35 time(s) in 31 post(s)		sorry about the bad spelling, "put" a dent in the amount..

Jd		Posted : Tuesday, 24 September 2013 11:37:59 AM(UTC)
Rank: Gold Nugget Medals: Groups: Registered Joined: 5/07/2012(UTC) Posts: 99 Location: Blenhim Thanks: 114 times Was thanked: 19 time(s) in 13 post(s)		I don't know who would want it I have advertised it in the past but its more of a young persons toy as it is and I don't think they are worth a lot but yer I could advertise it again and see what happens I would have more fun with the jet dingy though jd
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element111		Posted : Saturday, 19 October 2013 12:40:10 PM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 2/12/2011(UTC) Posts: 114 Location: blenheim Thanks: 49 times Was thanked: 34 time(s) in 21 post(s)		hay jd what sort of jet ski is it and how much you want for it ?I some one who could be interested

Jd		Posted : Saturday, 19 October 2013 7:05:50 PM(UTC)
Rank: Gold Nugget Medals: Groups: Registered Joined: 5/07/2012(UTC) Posts: 99 Location: Blenhim Thanks: 114 times Was thanked: 19 time(s) in 13 post(s)		Hay bud I ended up with it after a guy owed me $1500 so I was thinking my teen age boy would have some fun with it that was about 8 years ago it was serviced buy the guy in chch when I got it he checked it out and fitted a new battery and it has been in my shed ever since. its still in chch its a sit down one it has like a banana seat look I don't no what motor I am sure about 750 plus cc 2 stroke mix hope that helps jd
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