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Undersoul02

  • Karma: +16/-0
Berkeley Jet Setup questions???
« on: September 01, 2016, 02:43:32 PM »
So here it goes. I bought this 81 bubble deck Bahner last summer. I don’t know much, yet, about jets and how they should be set up as this is my first jet boat. What I’m trying to figure out is where to head from here with my Berkeley set up?

Here is what I was told by the previous owner about the motor. It is a Hardin marine 454, with a 405 Kit? Does that make sense? with somewhere between 420 and 450 hp.  At WOT I’m spinning around 5100 rpm (according to my tach) and I have no reason to believe that is inaccurate. The previous owner added tunnel ram with duel 650 Holley Carbs and a Marine MSD 6M 2L. I’m unaware of any other motor work done. He provided me with maintenance records from himself and the original owner dating back to 1982. I’m the 3rd owner of this boat. I wish I could provide more info regarding the motor package.

As far as the pump. It has a Berkely JG that is as far as I know is stock with a SE sport edition loader scoop. I’m assuming it’s an SE by looks only.  The only thing I’ve done to the pump is add a place diverter. Before I added the diverter I ran 64 mph via gps. After adding the diverter, I had no performance gain and speed remains at 64 mph. I don’t know what impeller is in the pump at this point. By the way it does have a delta pad bottom.

So my question is what should be my next step in regards to pump set up? I’m looking for more speed/performance at this point. From what I’ve read about these hulls I should be getting better speed/performance out of it even with my low HP motor set up. I just want to take the right steps first and not just start throwing things at it without getting feedback from you guys who know first.  So where should I head next as far as set up? Or what do you guys think?

Here are some photos of the set up. If I need to take more that’s not a problem. Thanks in advance.
« Last Edit: September 01, 2016, 02:50:17 PM by Undersoul02 »
  • Boat #1: 1981 Bahner
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roost

  • Karma: +10/-0
Re: Berkeley Jet Setup questions???
« Reply #1 on: September 01, 2016, 03:04:13 PM »
A couple things jump out at me. It could be an optical illusion, but the ramps on that loader look too low, but should be (roughly) even with the keel. 2nd, I'd be looking to make a ride plate for it to help get it on it's tail.
Be careful though. Speed costs money.... how fa$t do you want to go?
  • Boat #1: 1986 Commander Sunstreaker 21 open bow
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Undersoul02

  • Karma: +16/-0
Re: Berkeley Jet Setup questions???
« Reply #2 on: September 01, 2016, 03:12:15 PM »
The ramps do hang below the keel... here is another picture from the rear of the boat. As far as mph I'm looking for the best I can out of this motor at this point. The plan is to rebuild the motor in the next year or two. When I do I'll be looking for around 600 hp on the rebuild. I know I'll have to change impeller and other things when that happens.
  • Boat #1: 1981 Bahner
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FordLover

  • Karma: +72/-0
Re: Berkeley Jet Setup questions???
« Reply #3 on: September 01, 2016, 03:23:36 PM »
You want to go faster? Put a Ford in it. Lol, sorry, couldnt help it.

My 82 bahner bubble deck loves the ride plate. That bitch rides pretty far back without the diverter up. So I agree with Boost. Would be a good decently cheap start.
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Undersoul02

  • Karma: +16/-0
Re: Berkeley Jet Setup questions???
« Reply #4 on: September 01, 2016, 03:28:58 PM »
You want to go faster? Put a Ford in it. Lol, sorry, couldnt help it.

My 82 bahner bubble deck loves the ride plate. That bitch rides pretty far back without the diverter up. So I agree with Boost. Would be a good decently cheap start.

haha...I had a feeling a Ford comment was going to be coming my way.

As far as ride plates does the intake have to be modified to add a ride plate? or what are my options? What about a droop or straight snoot?
  • Boat #1: 1981 Bahner
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Blue2184

  • Karma: +4/-0
Berkeley Jet Setup questions???
« Reply #5 on: September 01, 2016, 03:40:58 PM »
Those loader ramps are WAY low... That's like a break on the bottom of the boat... I bet when you get off of the loud pedal it slows down FAST! I know not all boats are not the same! And you almost need to buy another loader identical to that one so you can start cutting on it... Take off a 1/4 of an inch at a time and go test it... How will you know enough is enough? You will start breaking the pump loose, and you can't really put it back after you cut it off, hints the second identical loader... Mine is about 3/8 of an inch above keel...


Sent from my shop setting in my boat making motor noises
« Last Edit: September 01, 2016, 03:45:46 PM by Blue2184 »
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Undersoul02

  • Karma: +16/-0
Re: Berkeley Jet Setup questions???
« Reply #6 on: September 01, 2016, 03:55:16 PM »
Those loader ramps are WAY low... That's like a break on the bottom of the boat... I bet when you get off of the loud pedal it slows down FAST! I know not all boats are not the same! And you almost need to buy another loader identical to that one so you can start cutting on it... Take off a 1/4 of an inch at a time and go test it... How will you know enough is enough? You will start breaking the pump loose, and you can't really put it back after you cut it off, hints the second identical loader... Mine is about 3/8 of an inch above keel...


Sent from my shop setting in my boat making motor noises

What do you mean by "breaking the pump loose"? Losing thrust? Would that be on take off or WOT? Is it possible this is the wrong Loader for this boat or it just needs to be cut?
  • Boat #1: 1981 Bahner
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Blue2184

  • Karma: +4/-0
Re: Berkeley Jet Setup questions???
« Reply #7 on: September 01, 2016, 04:03:14 PM »
Yeah you would be breaking suction with the pump cause the loader would not be feeding it enough water to keep the pump loaded, then you would be bouncing off of the rev limiter every time you hit any little wave on the water... You could prob trim that puppy flush with the bottom of the boat and be ok with what you have now... Once you step up the ponies later down the road then you will be (or should be) upgrading your loader anyway...


Sent from my shop setting in my boat making motor noises
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Blue2184

  • Karma: +4/-0
Re: Berkeley Jet Setup questions???
« Reply #8 on: September 01, 2016, 04:04:32 PM »
The loader doesn't do much for you on take off... Not until the boat is moving pretty good does it kinda start force feeding the pump...


Sent from my shop setting in my boat making motor noises
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Undersoul02

  • Karma: +16/-0
Re: Berkeley Jet Setup questions???
« Reply #9 on: September 01, 2016, 04:11:46 PM »
The loader doesn't do much for you on take off... Not until the boat is moving pretty good does it kinda start force feeding the pump...


Sent from my shop setting in my boat making motor noises

I'll be trimming it back and see what happens. Would the loader hanging that low cause the boat to ride wet as well? Even after I added the diverter it didn't feel like the boat road in more free at wot then it did before. Even trimmed out.
  • Boat #1: 1981 Bahner
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Blue2184

  • Karma: +4/-0
Re: Berkeley Jet Setup questions???
« Reply #10 on: September 01, 2016, 04:19:28 PM »
I guess to some extent it could be keeping the ass of the boat stuck to the water? I'm not real sure about the delta pad bottoms? When I first got my little bubble deck and started talking to gt about it my ramps were WAY low like yours... When I trimmed them down and went and test run it for the first time, when I went to shut it down after a wide open pass I was used to it almost acting like it had breaks when you got off the gas? That puppy just glided across the top of the water like it was on ice... So make sure you have plenty shut down room when you start testing... Cause I bet it's gonna free it up...


Sent from my shop setting in my boat making motor noises
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roost

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Re: Berkeley Jet Setup questions???
« Reply #11 on: September 01, 2016, 06:49:47 PM »
The loader ramps too low will at some point over-pressurize the intake. When that happens, a few different things will happen. The transom will rise and possibly blow out the pump. It can also rise and drop the bow. This creates bow steer and you don't want this. Every boat has a different fine line between loading the pump and over pressurizing the intake (or cavitating). When you make one change it will affect other parts of your setup. So, when you build 600 horses over the winter after getting the setup dialed in.... guess what? Yup, you get the start over.
  • Boat #1: 1986 Commander Sunstreaker 21 open bow
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