SoCal Jet Boats
Tech Talk => Jet Pumps => Topic started by: projectdaytona on January 15, 2008, 02:13:26 PM
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im building a 19 daytona with about 750hp. Im wondering if installing a jet away is a must? i heard that if i loose a motor at 80mph+ im doomed.. true or false? this is my 1st jet boat.
what is the complete purpose of them and what do they do how do they work?
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they serve 2 purposes....
First...they allow you to disconnect the drive line from the pump so you can run it on the trailer without worrying about burning up your pump....
second, they have a ratchet system on them to allow the pump to continue to spin and allow water to pass through in the event of an unplanned shutdown. in a tunnel/cat like your daytona....i dont think you have much to worry about. but in a v bottom or gullwing style boat, you will see violent bow steering. I got a small taste of it when my rogers blew.
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delete delete delete, Ya, like he said ;D
(hate that when someone posts while your posting, lol)
-Rebel
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they serve 2 purposes....
First...they allow you to disconnect the drive line from the pump so you can run it on the trailer without worrying about burning up your pump....
second, they have a ratchet system on them to allow the pump to continue to spin and allow water to pass through in the event of an unplanned shutdown. in a tunnel/cat like your daytona....i dont think you have much to worry about. but in a v bottom or gullwing style boat, you will see violent bow steering. I got a small taste of it when my rogers blew.
so basically its not a must have for my tunnel that will run low-mid 80s im thinking? how much do they run?
Would i need a short drive shaft?
i have a buddy with a cp that says its a must for his boat and i should look into one.
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oh...how long can i run a boat out on the trailer without burning my pump. I was thinking 1 or 2 minutes
water to the motor of course
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they run about $1300 and you very rarely see them for sale used. Yes, its a wise item for our buddy's CP, but being your boat has 2 sponsoons to distribute the weight across, i don't think a daytona would bow steer badly. I might be wrong, I don't know much about the handling of a daytona.
any amount of time dry running your pump isn't safe....its a debate that will never come to an end. Some people say they do it all the time without any problems...others have done it once or twice and have seen dramatic consequences.
Tom has them here: http://www.jetboatperformance.com/index.php?p=jetaway
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thanks for the info brad!
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unfortunatly i have had my daytona die on me at speed and it tracks very nice ;D
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oh...how long can i run a boat out on the trailer without burning my pump. I was thinking 1 or 2 minutes
water to the motor of course
I'd never run without water, however, can run all you want if running water in it; why would you run water thru the motor but not the pump:
If you run water thru the pump, there is NO PROBLEM running it out of water.
I used flytime's idea: put a hose splitter on the hose; one hose from splitter has male connector, the other has female; disconnect interior hoses then connect to splitter hoses; turn pump water on before turning engine; turn engine water on after engine starts.
I read much on this; many say never do it, BUT, flytime told me he checked with Berkeley directly, then I emailed Berkeley and got a quick reply that it is NO PROBLEM if running water in the pump.
In fact, the Berkeley guy said run a hose up the nozzle; but it's better to disconnect the inside hose and run it directly into the pump (connecting another hose to run thru the engine to cool).
http://www.socaljetboats.com/index.php?topic=556.msg16667#msg16667 (http://www.socaljetboats.com/index.php?topic=556.msg16667#msg16667)
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im building a 19 daytona with about 750hp. Im wondering if installing a jet away is a must? i heard that if i loose a motor at 80mph+ im doomed.. true or false? this is my 1st jet boat.
what is the complete purpose of them and what do they do how do they work?
u can also run a pop off valve on the clean out part of the pump it works similar but still wont be able to run it out of water u can find them on drag boat links about half the price of a jetaway
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I had my pump rebuilt by MPD , Jack does not recommend running your boat out of the water, ( front seal doesn,t get water or at least not much) but he said you can if you have to , do it like Wanabe said and run water in your pick line and run a hose through the back of the pump.
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With a fresh jet no ,prolly' not a good plan ,but truly if you ponder it with good bearings and bushing the impeller wear skirt is technically "centered/suspended" in the wear ring with clearance and wont touch ,rub or abrade (or "Grow" less you buzz the motor) . If its absolutly neccesary ,its unlikely a problem will occur (sans grit, dirt etc) When its neccesary and unavoidable run a second seperate water source to the jet (in the intake or in the cleanout) just my 02
re jetaways ,my hats off to Duane etc ,Best thing since Beer in cans and The socal "what a piece of a$$ thread" ;) ;) ;)