Jet Rebuild info needed

I have never done it before, but I want to try to rebuild it.

It is a berkley Jet

1. How hard is it going to be for me to remove for the boat itself? Is there anything need to be aware of and are there any tricks to make this removal easier?

2. Are there any uncommon tools that I will need for the removal or the rebuild? I have pretty much everytool you could want to wrench on a car or motor, but the jet is not famaliar ground for me.

3. Lastly i have access to a machine shop and some pretty talented machinest. I was speaking with a guy who used to race jet boats and he was trying to explain to me how easy to blue print a jet. Does anyone suggest me doing it myself or should i use a shop? Secondly are there any specs or drawings on how to blueprint a jet?

Thanks for all the help.

Joe

if you are mechanically inclined, you can do it.
download the instructions from Berkley or American turbine websites.

there's a tag on the pump above the bearing that contains a serial and model #. post this info and some pics and we can walk you thru it.

you will need a couple of special tools to complete it. I made mine.
no big deal.

I like the instructions from American turbine.com
click on support then instructions and service manual at the bottom of the page. its a 13 page PDF.

River Runner said:

I have never done it before, but I want to try to rebuild it.

It is a berkley Jet

1. How hard is it going to be for me to remove for the boat itself? Is there anything need to be aware of and are there any tricks to make this removal easier?

2. Are there any uncommon tools that I will need for the removal or the rebuild? I have pretty much everytool you could want to wrench on a car or motor, but the jet is not famaliar ground for me.

3. Lastly i have access to a machine shop and some pretty talented machinest. I was speaking with a guy who used to race jet boats and he was trying to explain to me how easy to blue print a jet. Does anyone suggest me doing it myself or should i use a shop? Secondly are there any specs or drawings on how to blueprint a jet?

Thanks for all the help.

Joe

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sorry joe, these questions are land mines. it may be easy if you succeed and near impossible if you fail. good mechanical skills and great reasoning will help. the pump may come out easily it may take hrs. it may come apart easily it may take hrs. have most every tool known to man and several cncs did a pump last month that took me over 6 hrs to get the front bearing out without breaking the suction housing. did a pump last week and this was a first had to use a plasma cutter to cut the impellor off the shaft. custom made and factory socket 1 13/16 needed would not even move it. looked perfectly clean but salt erosion had welded it to the shaft and it would not move. have on the lucky side took pumps apart and hand pulled the impellor off, doesnt happen often. great info from a t and berkeley in the repair manuals, dont mean to rant, go slow and easy and dont break anything if you need help get on here and ask questions, great bunch of guys with a lot of info.

Joe , although Jets can be a little tough to disassemble and as said "some special tools" help but lots of folks with basic mechanical skills and some basic tools do these regularly , theres real no "vooddoo" to them and they are actually relativley primitive in design and quite simple to work on Theres no springs , check balls and odd little pieces also not alot of pit falls (unless someones made internal changes prior) . Both Berkeley and American turbine have adequate online instructionals to help. Regardless of where you buy parts , Josh or I give live personal phone tech assistance daily from 10 to 6 pst at our regular number to help you with this if you decide you wish to tackle it. I also take tech calls evenings and weekends (pm for my cell) Let us know if we can help Tom @ JBP

jetboatperformance said:

Joe , although Jets can be a little tough to disassemble and as said "some special tools" help but lots of folks with basic mechanical skills and some basic tools do these regularly , theres real no "vooddoo" to them and they are actually relativley primitive in design and quite simple to work on Theres no springs , check balls and odd little pieces also not alot of pit falls (unless someones made internal changes prior) . Both Berkeley and American turbine have adequate online instructionals to help. Regardless of where you buy parts , Josh or I give live personal phone tech assistance daily from 10 to 6 pst at our regular number to help you with this if you decide you wish to tackle it. I also take tech calls evenings and weekends (pm for my cell) Let us know if we can help Tom @ JBP

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He isn't kidding. And don't be surprised when you get the random call after your done to make sure your still all good or have any other questions:thumbsup. You don't find that kind of customer service very often.

On a lighter note Tom it looks like we'll be getting the boat wet in a couple weeks. I'll let you let you know how it turns out.

Dont get any better than Tom @ Jet Boat Performance

:thumbsup to tom good guy

lv4jetboats said:

Dont get any better than Tom @ Jet Boat Performance

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What is the general costs with taking a jet to a shop for repair??
Here's my question I have a 91 Ultra jet with berkley jet(JG with a B impeller I believe)and last summer I experienced loss off power with a full cargo (6 full adults) the boat barely got on plane after someone when to the bow....so I think it's time for a rebuilt myself any thoughts...sorry for the highjack and would I might be better off with a C impeller? for more top end?

chevy 454 -330 hp if that helps

j-rod said:

What is the general costs with taking a jet to a shop for repair??
Here's my question I have a 91 Ultra jet with berkley jet(JG with a B impeller I believe)and last summer I experienced loss off power with a full cargo (6 full adults) the boat barely got on plane after someone when to the bow....so I think it's time for a rebuilt myself any thoughts...sorry for the highjack and would I might be better off with a C impeller? for more top end?

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can be different variables to consider.1 pump might be getting tired 2.might be motor issues and not the pump and so on and so on.did you do anything different before this started to happen

i did hydro lock motor 2 years ago but pulled motor apart and everything looked fine and no performance issuses after re-install.

have you run your boat before with that many people and if yes i take it ran like a champ.might be the tolerances in the pump are not as tight as they used to be. tom at jbp can give ya the insight you need

Today I went out to the river and removed the pump and it took about 1-1/2 hours, but it was pretty seamless. Next step is taking it home rebuild, Blueprint, powdercoat and install. I will start to start to post pics once i clean this beast up.

- On a side note, no problem on the highjack. J-rod My boat is also a 21' 91 Ultra with a 454, pretty funny how we have the exact same boat and similar issues. My boat is a 12JC with a type A Impeller. Like year I went through the motor and fixed any issues. This year in the winter I started to loose power, I ran it 1 more weekend and it felt like something would slip, my diagnosis was the pump was starting to go and there was water slipping past the the bowl. I could be way off base on the problem, but i will let you know how it turns out.

ok here my deal had the boat serviced ,guy said pump looked good some tolance issuses but I should be able to use it this summer without any rebuilt, I still need some plugs and wires and still had some issuses with perfomance, but after driving for bout an hour blew the carb out and got performance back!!!!!!

River Runner said:

Today I went out to the river and removed the pump and it took about 1-1/2 hours, but it was pretty seamless. Next step is taking it home rebuild, Blueprint, powdercoat and install. I will start to start to post pics once i clean this beast up.

- On a side note, no problem on the highjack. J-rod My boat is also a 21' 91 Ultra with a 454, pretty funny how we have the exact same boat and similar issues. My boat is a 12JC with a type A Impeller. Like year I went through the motor and fixed any issues. This year in the winter I started to loose power, I ran it 1 more weekend and it felt like something would slip, my diagnosis was the pump was starting to go and there was water slipping past the the bowl. I could be way off base on the problem, but i will let you know how it turns out.

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RR let us know as you tear into it post up some pics and progress info Your diaog is likely correct High rpms vs speed and performance usulaly equates to internal jet wear and issues Tom

The job isn't hard, but to do it right requires time and attention to detail. When I diagnosed my failed pump and built a new one last year, I noticed a handful of problems with even the new parts that I feel were unacceptable and needed to be addressed.

You don't have a whole hell of a lot of clearance to deal with between the wear ring and the impeller pilot. Most like to see the diameter difference at 0.025", which leaves you only 0.0125" of clearance. I don't think the actual clearance number is too critical to a point...I think what really matters is that the clearance does not fluctuate due to runout in the assembly. I've seen pictures of shops machining impeller pilots on a lathe using a simple 3 jaw chuck....I've never seen a 3 jaw chuck that's accurate to more than about .003". I set mine up in a 4 jaw and spent a lot of time on setup, screwing it up a few times due to making assumptions that I shouldn't have made, but at the end of the day I ended up with less than .0008" of runout at any point on the shaft/impeller assembly. Runout when I started was over 0.004". Contributors were: The center hole of the impeller was not in the true center in relation to the pilot, the center hole in the impeller was almost .0015" larger than the shaft, and a little bit of runout in the shaft itself. I ended up knurling the shaft slightly to make the impeller fit snuggly, straightened the shaft as best I could, then machined the impeller pilot undersize and true to my now straight pump shaft. With virtually zero runout on the entire rotating assembly, the pump performs considerably better...my wear ring clearance is a bit closer to 0.015 than 0.0125, but it's constant and I think that's the most important part.

Attn to detail is key.