SoCal Jet Boats

Tech Talk => Jet Pumps => Topic started by: spectramitch on July 03, 2020, 01:54:45 PM

Title: Suddenly a Vibration
Post by: spectramitch on July 03, 2020, 01:54:45 PM

I was out yesterday on my Spectra 20 BBF Berk 12jc w dominator bowl and sport loader. Ran good all day. Going back in, driving 20 min all of a sudden while on plain I felt the hull was vibrating. Almost felt like driving on a gravel road.  I went through a no wake zone and at idle it sounds and felt normal. Tried to put back on plain and it was vibrating enough to make me want to just idle it back to the ramp. Looked at loader, impeller, and exit veins and saw nothing abnormal. I know its possible something i sucked up fell out. I moved pump shaft up down left and right and was tight, no play. But when I rotate it there is play in the U joint. What do you guys think?

Title: Re: Suddenly a Vibration
Post by: angermgmt on July 03, 2020, 01:57:57 PM

Anything wrapped around the shaft.


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Title: Re: Suddenly a Vibration
Post by: spectramitch on July 03, 2020, 02:00:40 PM

Nope nothing around shaft when I pulled boat out


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Title: Re: Suddenly a Vibration
Post by: angermgmt on July 03, 2020, 02:29:14 PM

Maybe you vaporized a fish


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Title: Re: Suddenly a Vibration
Post by: Flusher on July 03, 2020, 05:26:28 PM

Is the play in the u-joints?  Replace them!  Don't let it fail.

Is the play in the splines of the shaft?  A tiny amount is normal.  It is bad when the splines bind.

Title: Suddenly a Vibration
Post by: spectramitch on July 03, 2020, 08:16:19 PM

There is play in the u-joints. When on the trailer running its always made a clattering rattling sound. But in the water idling and driving, it was quiet and normal until now. How much play is too much in the U-Joints?


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Title: Re: Suddenly a Vibration
Post by: 76Mantra455 on July 03, 2020, 08:49:58 PM

I would replace the u joints start there..have you greased them lately?

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Title: Suddenly a Vibration
Post by: zonahawk on July 05, 2020, 02:33:26 PM

I’m having almost the same symptoms... I was fearing bearings as I KNOW I should have grease them more often... I have an insert pump, just noticed a little water bleed on the top of the housing as well... hmmm. When I try to get on it it feels like something is wrapped around the shaft. But it idles fine and has nothing visible wrapped around the shaft.  When I run out of water it makes a loud hollow sound, like metal on metal


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Title: Re: Suddenly a Vibration
Post by: spectramitch on July 06, 2020, 06:11:53 AM

I water tested it again and the vibration is gone. It runs good and pulls hard again. It must have been something stuck either in jet or on loader and then came out when put on trailer. My U-joints are definitely going out. When I run out of water it clatters so bad. In the water I can only hear the U-joint slop if you blip the throttle and pull back quickly. I'm going to pull the motor and install the new U-joints. My question is; Is it possible with a 3 point Hardin bell housing to Remove PTO and run motor? It looks tough to do but has anyone done it?

Title: Re: Suddenly a Vibration
Post by: zonahawk on July 06, 2020, 09:19:25 AM

I water tested again and it starts and idles great.  When I try giving it more than a thousand RPM it put a serious load on the motor and if I don’t back it off just right it stops it... I’m guessing I fried a bearing??  If anyone has advice I’m all ears, this is a built in pump.


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Title: Re: Suddenly a Vibration
Post by: angermgmt on July 06, 2020, 09:50:23 AM

What do your u joints look like?


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Title: Re: Suddenly a Vibration
Post by: zonahawk on July 06, 2020, 12:55:07 PM

Tight!


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Title: Re: Suddenly a Vibration
Post by: zonahawk on July 06, 2020, 12:59:31 PM

Ok I found it!! 


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Title: Re: Suddenly a Vibration
Post by: angermgmt on July 06, 2020, 02:02:40 PM

Ouch


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Title: Re: Suddenly a Vibration
Post by: TrollerDave on July 06, 2020, 06:35:43 PM

Quote from: zonahawk on July 06, 2020, 12:59:31 PM

Ok I found it!! 


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Dude! Good find. At least now you can justify going through everything and rebuild your pump.


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Title: Re: Suddenly a Vibration
Post by: angermgmt on July 06, 2020, 06:44:42 PM

From the picture it appears in my opinion you sucked up a bog rock and it slid till it stuck at rpm and smack.


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Title: Re: Suddenly a Vibration
Post by: zonahawk on July 07, 2020, 06:40:19 AM

Yes the pump was the last old piece... bound to fail!  Anyone know for sure how this pump is serviced?   Motor must come out if I’m not mistaken...


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Title: Re: Suddenly a Vibration
Post by: zonahawk on July 07, 2020, 10:47:08 AM

Not able to get the bowl to slide off aft... how hard can/should I pry?  It slides back about 1/2 inch then stops.  The wear ring looks melted


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Title: Re: Suddenly a Vibration
Post by: zonahawk on July 07, 2020, 12:22:28 PM

99% sure I spun the wear ring and really chewed up the housing...


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Title: Re: Suddenly a Vibration
Post by: angermgmt on July 07, 2020, 12:41:37 PM

🤯


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Title: Re: Suddenly a Vibration
Post by: Flusher on July 08, 2020, 06:55:08 AM

Quote from: zonahawk on July 07, 2020, 10:47:08 AM

Not able to get the bowl to slide off aft... how hard can/should I pry?  It slides back about 1/2 inch then stops.  The wear ring looks melted


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DO NOT PRY!!!

Partially thread in two bolts (6 turns min.) at approximately 3 and 9 o'clock positions and give the bolt heads a few sharp blows with a hammer.  Don't whale on them, it just takes a little motivation to move the bowl.  There should be an interference fit between the suction housing and the bowl to properly register them together.  Just make sure that you have good thread engagement so you don't damage the threads.  Lastly, the bolts prevent the bowl from falling off unexpectedly.

It is best to service insert pumps in the boat.  Don't try to remove the suction housing, they are a huge drama to R&R.

Hopefully the housing is still usable, they are crazy expensive to replace.  Usually what happens is, when the thrust bearing fails, the impeller saws through the housing, into the hand hole cover bore.

You should also check your engine oil for metal particles.

Title: Re: Suddenly a Vibration
Post by: zonahawk on July 08, 2020, 08:05:07 AM

I don’t see how I could give much of a whack to the bolts in the bowl with how much space I have between the transom....  I will try.  I guess the good news it that I definitely didn’t get to the hand hole cover!


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Title: Re: Suddenly a Vibration
Post by: Flusher on July 08, 2020, 08:49:21 AM

Quote from: zonahawk on July 08, 2020, 08:05:07 AM

I don’t see how I could give much of a whack to the bolts in the bowl with how much space I have between the transom.... 

EXACTLY!!!  Choke up.  No back swing.

Quote from: zonahawk on July 08, 2020, 08:05:07 AM

I guess the good news it that I definitely didn’t get to the hand hole cover!

Not yet, you need to take it apart and see how bad it really is.

Title: Re: Suddenly a Vibration
Post by: Flusher on July 08, 2020, 11:52:16 AM

Quote from: zonahawk on July 07, 2020, 12:22:28 PM

99% sure I spun the wear ring and really chewed up the housing...


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Hopefully this wear ring bore isn't damaged, because it will never be able to support a wear ring properly again.  The face in front of the impeller can tolerate a certain amount of damage.  When the fresh clearances are set, the impeller can be moved forward by turning the shaft an appropriate amount.

Please don't be tempted to face the front of the impeller hub, to move the impeller forward.  That absolutely destroys the impeller and every RPM range will suffer a huge performance hit.