How to Assemble a Berkeley 12JG Jet Boat Pump

[@eliminator1978]

Love the jet boat content. Wish there was more on KZbin

[@AutoTechNick]

🙏 Thank you!

[@jaredstafford5565]

Nice!! Thanks for the informative video. 👍

[@AutoTechNick]

Absolutely! I hope that it was helpful for you.

[@DustinMercadoWillis]

Thanks bro. Do you have a video showing the installation of a place diverter?

[@AutoTechNick]

Not yet, but I will shorty. I need to finish off the gelcoat in my bilge, then I can work towards rigging the boat, including the place diverter installation.

[@henryhenry3832]

Great video

[@1977meteor]

Great vid. Will be very useful when I come to rebuild mine. Out of interest have you had any experience with the seal you can buy to replace the rope seal system. It's quite an expensive seal but I prefer the idea of not having drips of water coming through and having to periodically adjust the rope packing.

[@AutoTechNick]

I have only run the rope seals, so my experience is limited to those. I am glad that you enjoyed the video. ~ Nick

[@npalmi88]

I really like the simplicity of this unit. I plan on converting a stern drive houseboat to diesel jet drive with this. Why do they use what are basically nylon rope pieces as seals on the inside shaft though?

[@AutoTechNick]

I agree that the rope seals seem like a pretty primitive means to seal the suction housing shaft, but I think they provide the best function vs cost. Depending on the application the suction housing can see quite a lot of pressure, well over 50psi. That in combination to the fact that you have to seal pressure from a spinning shaft means that the rope seals, although primitive are a very effective solution.

[@AutoTechNick]

That sounds like an interesting project with the jet drive and house boat!!

[@npalmi88]

@@AutoTechNick Would this be able to handle it? It’s a 1978 Holiday Mansion (36 foot), which I think displaces about 12,000lbs. I plan to use a Cummins 6BT. Speed is not important to me, I only need to be able to do about 10mph.

[@AutoTechNick]

My biggest concern would be maneuverability… I am unsure if you have been behind the helm of a jet drive equipped boat before, but the low speed maneuverability is pretty much non existent. With that much weight and that big of a boat, living at such low speeds I fear that you would have very little control of the vessel.

[@npalmi88]

@@AutoTechNick hmm, the whole reason I wanted to do this is I want to go diesel and the sterndrive can’t handle the torque, I’m told. Maybe there is a simple way for me to go straight shaft. I’ll keep researching. Thank you for your knowledge.

[@fieldsken1]

Did you check the clearance on the impeller to wear ring

[@AutoTechNick]

Ken, There was no need to measure those tolerances in this instance. This pump was rebuilt years ago, and then set on a shelf. I then took it apart to re-paint it. All the components that went back into it during this video were the items that came out of the pump. All of the clearances were set during the rebuild, nothing changed. This was basically a dissasembly and re-assembly with a paint job in the middle. ~ Nick

[@jetneptun]

Cool job! I also built a jetboat with berkeley. I have a video on my channel.

[@mikeludwig7286]

What did they set the impeller to wear ring clearance? You did not check it on your video?

[@AutoTechNick]

Mike, the reason that I did not check the clearance in the video is because the pump was rebuilt by the crew at CP Performance a few years ago and the clearances were set by them at that time. After the rebuild it was stored in the shop and not used. I then took the pump back apart to repaint it before it was ever installed or ran. So I there was no need to go back and check them as nothing changed. As for my clearance it was at .025” with my stainless impeller. ~ Nick

[@Tchrome_84]

How do you feel about a stainless bolt to cap the oil off on the bowl? Just curious cause i ordered a stainless bolt.

[@AutoTechNick]

I have no issues with them. The plastic ones are a bit frail, but that only matters during assembly. I'm still running a plastic one, but if it were to brake I would switch to a stainless. ~ Nick

[@joshwillems7287]

Did you check to se if the impeller will spin by hand after installed. I just rebuilt mine and it’s a new wear ring that has a lip inward and if I torque it to 75 ftlbs I can’t spin it by hand

[@AutoTechNick]

Yes. I was easily able to turn the impeller after torquing the nut. From your description it sounds like you have a "shouldered" wear ring, and the fit for the impeller is too far forward, causing the interference. If this is the case, you can buy a shim kit from CP performance that will move the impeller rearwards and correct interference issued with the wear ring. I put a link to the shims that I am referring to. www.cpperformance.com/p-960-shim-kit.aspx

[@austinivan]

What oil do you put in the bowl and how much?

[@AutoTechNick]

I use regular 90w gear oil. I fill it up until it starts to come out of the fill hole on the bowl. ~ Nick

[@bodeine454]

I'm almost through the video but something that seems odd to me is that I don't believe I've seen a washer yet being used on any bolts here, do you know why that is?

[@AutoTechNick]

I assume you are referring to the bolts that secure the bowl to the suction housing. In that case neither my Berkeley or Dominator pump have washers on those locations. Also if I remember correctly the shape of the flange on the suction house has a radius that is very close to the bolt location which could interfere with a washer. I have had no issues with washerless bolts, but keep in mind I also use Blue Loctite on my hardware as well. ~ Nick

[@bodeine454]

@@AutoTechNick Ok, I think I understand for the most part. What about the impeller? I didn't see a washer on that big nut either. I'm not saying it's wrong I'm just not used to seeing that many nuts and bolts without washers. Also, in some cases, not having washers on the fasteners can throw off the torque settings when you torque them down. 🤷‍♂️

[@AutoTechNick]

@@bodeine454 You do have a good point about not achieving the proper torque without having a washer. However for the impeller nut you referenced, it is a nylock nut. The nylon locking feature of the nut will create a high running torque anyways, which will have a effect on the actual final torque. I do agree with you that when dealing with a critical torque that you should be using a washer or the proper lube on the nut to reduce friction & ensuring that the correct torque is achieved. However we must remember that these pumps are fairly crude in design. They were designed, and in most cases built in the early 60's. A lot in technology, design and manufacturing has changed since then. ~ Nick

[@ryandonnelly2818]

What kind of paint did you use?

[@AutoTechNick]

Ryan, I used acrylic enamel paint for automotive use. It was a single stage paint, but I ended up adding clear coat over it. If you haven’t seen the video where I covered the pump re-paint here is the link: kzbin.info/www/bejne/p5W2ioCJZ6p1o9k ~Nick

[@Yorchoice1]

Can that jet will move a 22' cc project boat?

[@AutoTechNick]

Wilfredo, I am not too sure that I know what you mean by 22' cc.. If by 22' foot long boat then yes it will be just fine.

[@Yorchoice1]

Thank you. And how much do they go for

[@AutoTechNick]

That really depends on the components that are installed in them and the condition. I’ve seen them from a few hundred dollars to several thousand. ~ Nick