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Newbe to jet boats have some questions

3K views 19 replies 8 participants last post by  Kona73 
#1 ·
We just got a 73 Kona jet boat all their but a mess. jet drive was disconnected from motor 454 know for the questions.
1) is there a way to tell if jet drive is good other then looking for waer signs or broken ? as it spins freely and all looks good
2) previous owner ran hoses from jet pump for water intake up to drivers seat to control water flow witch other tehn changing the hoses to high pressure looks good, but the question is can you run the motor if drive is not engaged or will it not get water flow? if this is the case do you need to run a seperate pump to push water ?
Thanks for the help as have been looking around here and like it just not sure how may are in my area Phila, pa
 
#2 ·
Well i will give you some info from what i have learned over the years of jet boating.

? 1) inspect the impeller thru the hand hole cover and intake on bottom of boat. Thru the hand hole cover grab the impeller shaft and try to move it up and down if you can you will need to pull the bowl and install new bowl bushings and repair the impeller shaft if it's worn. at that point you will want to make sure the impeller wear wring is OK by pulling the impeller and inspecting.

? 2) you can run your engine out of water by hoking up your garden hose to the line coming off your pump that go's to the engine. You want the pump disconnected so you don't case premature wear. so drive line disconnected is a good thing for running out of water. If you tried to run the boat in the water with the drive line disconnected it would not supply water and you would over heat your engine.

GOOD LUCK and post some pic's!!!
 
#3 ·
Hook everything up and put it in the water. Good starting point unless you have a whole in the hull or something.
Can always start it up on the trailer at the launch if you just want to be checkin' stuff.:)bulb

Me and a friend are well into a 73 Kona project right now, and we would love to see pics of yours.:)devil
 
#5 ·
Thanks for all you help. next question is when the jet is hooked up and boat is in water, if you are not moving will water ( jet not engaged) still flow through the engine if not is their some kind of setup to pump water through engine when not moving. ( how long can you idle the motor if not moving and still get water flow through engine). Thanks
 
#9 · (Edited)
Thanks for all you help. next question is when the jet is hooked up and boat is in water, if you are not moving will water ( jet not engaged) still flow through the engine if not is their some kind of setup to pump water through engine when not moving. ( how long can you idle the motor if not moving and still get water flow through engine). Thanks
Hey Ive looked at your pics . I hope I got your questions right. Ill try and list them then answer them.

1. does the motor get water when you are idling when the boat is in water ? Yes it does. Your motor is hooked up directly to the Pump with that the short Drivelive ( which is that piece with the U joints ) . If the motor is turning , and that jet is sitting in water it is always turning and pumping water no matter if your idling or running full throttle.

2. How long can you idle ? As long as the boats in the water. indefinatley unless your pump stops working :(



Hope that helped
 
#8 ·
interior

here is pic of interior and if look close next to driver seat and diverter control are the valves previous owner installed to control water flow and to build up temp to engine, one cotrols flow into motor another controls flow out and then there is a bypase valve.
 
#10 ·
DK_ Hallet, yes that was what we were looking for was abit nervious to put in water and not have any water flow as have couple friends with V-Drives and they have water pumps. put alot of work into her already as motor had a miss to it and a tapping and some milky oil when bought it but under water flow oil stay same so took shot that problems were from sitting for 8 years, so after a tune up oil change and replacing some of the hoses and flushing out both gas tanks and a valve adjustment shes running fine just getting ready to put her in the water and didn't want to screw any thing up . thanks
 
#14 ·
Plugs



There are two 1/8th NPT plugs on the bowl, at about 10 and 2 o'clock . Pull BOTH plugs to allow air to escape while filling the other side. 90wt is OK, light grease is also OK. There are also pumps that use just water to lube the rear bushing, and if that is your case, be careful running out of water for any length of time........Also.......If you highway tow to the water, there is a good chance of debris getting in the pump from the road. Back the boat into the water enough to clean that out before firing dry on the ramp.......I always bark the engine on the ramp before launching, just to be sure it's going to start......5 seconds or so......Ray
 
#16 ·
1/4 ??



OK, yours may be out to 1/4 NPT, but the drill is the same. Open them both, fill one, allowing air to escape through the other one......When it reaches the top, stop and plug them up......You may get a little seepage into the bowl, that is somewhat normal...........Ray
 
#17 ·
push oil through till it comes out clean (in one out the other) oil coming out the bowl is normal if you push to hard no you did not blow out the seal it faces towards the water to keep the water out of the oil not he other way around
 
#18 ·
Ok so fixed wiring that was a mess pulled clean out and cleaned out bunch of debris checked shaft no play in it replaced some bolts everywhere and started to replace the 2 bolts for the gland bushings how tight are these bolts soppose to be as when lossening the old rusted ones noticed play in shaft increase so I don't want to over tighten new ones and cause bushing to wear out prematurely
 
#19 ·
Ok so fixed wiring that was a mess pulled clean out and cleaned out bunch of debris checked shaft no play in it replaced some bolts everywhere and started to replace the 2 bolts for the gland bushings how tight are these bolts soppose to be as when lossening the old rusted ones noticed play in shaft increase so I don't want to over tighten new ones and cause bushing to wear out prematurely
Choke up on a small 9/16 wrench with thumb and forefinger and put them barley snug , overtightening will cause the packings to "burnish" and leak more not to mention shaft wear etc Tom

btw concerned about the comment highlited above? what "play" increased" ?
 
#20 ·
when loosen the old bolts the shaft felt like it had more play in it then when they were tightened. So when went to put in new blots was not sure how much to tightened as had looked at then diagrahms to see what was there and figured that if I tighten them to much would affect the gland seal on the shaft. the shaft spun with some tension on it after taking out the bolts that tension was gone. Hope that explains it better.
 
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