[Shaun]

I'm starting this post because there seams to be very little info on these pumps, i have 3 of them right now and im gathering as much information as possible on them so that hopfully others who are going to use them and looking for info on them will find this thread. If any of you guys have any info, post it, and lets get as much info on in the thread as possible.

From what i've been told so far these pumps were made for small boats, sounds like they never really took off. Sombody at cp performance told me berk went bankrupt and cp aqquired berks stuff. Cp i guess didnt really get any info on these pumps from berk and so nobody there really knows anything about them, least nobody i have talked to yet. They aquired the stock that was left and i guess they are no longer making these or parts. They have some assembled units left from what i've been told.

 

[Shaun]

Here's a list of part numbers off my pumps

H2446 --> Intake/Suction

L3920 --> Nozzle/Reverse

6JA CW --> On top of intake/suction

L3857 --> On what i would consider the bowl.

6048 --> Impeller, light, aluminum, probably for smaller hp apps
casting isnt as bad as 6084

6084 --> Impeller, very light, crappy looking casting, looks like
it's probably for very small HP applications

xxxxx --> Impeller, Bronze, heavy, probably for higher HP apps
couldnt read the part number off the end.

L4217 --> Ride plate, bolts to the back of the intake/suction.

 

[Shaun]

I found this on the net, it looks like these pumps where used in the first Seadoo's. The 6ja model had a whoping 25.3HP motor butted up to it. Ran 6000RPM.

The 5J5 model had a 18HP motor connected to it and ran 6000 RPM. The 5j5 pump was driven by a timing belt.

 

[Shaun]

Here's some more docs that CAS here on the forums posted in another thread.

 

[Shaun]

Stole this from another site.

Intake Grate Performance Modifications:

If you want to get the most out of your Berkeley 6JA Jet Pump, then you need to improve its efficiency. The intake 5 fin intake grate is very restrictive to waterflow. Not only is it restrictive, but the fins are flat where they face the water. This "un-aerodynamic" edge creates a tremendous amount of water turbulence going into the pump. The more water you can get into and through the pump, the more force it will produce. Of course the horsepower of the engine and bit of the impeller come into play as well, but any improvement....up to the point at which the engine can't power it, or the impeller can't move it....is still an improvement.

• First, cut out 2 of the fins on the intake grate.
• Next, use a die-grinder with a coarse bit designed for aluminum and grind the top and bottom edges of the fins so they are very airfoil shaped...like an airplane wing in cross-section
• Next, put a 3/8" radius on the back curvature of the grate where there is currently a sharp wedge shaped edge.

Note the difference in the "before" and "after" pictures!

This is the unmodified pump intake grate

This is after modifications

​

 

[Shaun]

Stole from the same site..

Jet Pump Lubrication:

The owner's manual suggests using 20w oil in the jet pump. That seems way to thin to me, for bearings that are spinning at close to 7,000rpm. Plus, if you use automotive oils, which contain sulphur, they will make sulphuric acid if water gets in past the shaft seals. This will quickly eat the bearing surfaces and destroy them.

• My suggestion would be to use Marine grade gear oil, especially synthetics. I'm using the 85/90w oil in mine.
• Fill the cavity that's under both of the red screw in caps in the photo below. The cavity nearest the engine is the actual bearing, with a seal on either side. The cavity nearest the stern is just a set of seals to keep water out and protect the bearing.
• Some marine places that service Berkeley Jet Pumps will suggest using marine grade grease. I think that works well too. I decided to use gear oil instead, because I wanted something that would flow and circulate around the bearing. My thinking is that grease is thicks, so there's some drag on the pump that takes horsepower to overcome, and grease doesn't circulate, so your bearing is always running in the same bit of grease. Maybe that's not correct, but that's my thinking for now.
• There is one other lubrication point out where the pump shaft rides in the tail housing of the pump. If you look into the back end of the pump you'll see another screw-in plug there in the center of the Stator. Lift the rear of the Sea Doo 3' higher, so you can pour marine grade gear oil into the tail shaft bushing. Then replace the plug. Alternatively, you could remove the pump nozzle and bowl/stator housing and put marine grade grease inside the bushing, and then slide the stator back on and reassemble.
• It's a good idea to check the oil or grease (which ever you're using) levels every couple of rides depending on how long you go out for. It would be a shame to burn up a bearing or tail shaft bushing do to a lack of oil.

2 lube points for the jet pump bearing and seals

remove the red plugs and fill the cavities


Tail shaft lube point is inside the jet nozzle

Raise the rear of the Sea Doo, remove plug and fill this cavity.

 

[Shaun]

Now for some of my findings..

Removing the Impeller

The impeller is threaded onto the shaft, the threads are standard meaning you need to spin the impeller counter clock wise to remove it. The impeller has holes drilled into the front of it, the holes look to be for some sort of tool that fits into these holes and acts like a wrench to spin the impeller. What i did was put some all thread into the holes and then used a adjustable wrench to turn everything (see pic below). If you look into the intake/suction you will see the shaft, spin the shaft until you see the hole that runs through it. My guess is that this is a way to hold the shaft when removing the impeller.. least thats what i used it for. Stuck a long screw driver through it to keep the shaft from moving. I did three impeller removals in one day, one of them was already loose so that was a easy removal but the other two were not so easy. When trying to remove them the all thread was tweaking sideways and i was affraid i was going to ruin the impeller. What i found that worked great on both impellers was to heat them up first, i hit them with a propane torch for 5 minutes or so and then i let them cool alittle, once i did this the impellers came off pretty easy. I'm going to attempt to make a tool to fit these impellers, if you had a tool that would keep the all thread/pins from tweaking you would have a better chance of not ruining the impeller. Actually the tool to tighten the wheel on my grinder fit perfect! it just wasnt strong enough an i was bending it.

​

 

[Shaun]

more of my findings..

I have 3 pumps, they all say 6JA on the casting but one of them had a metal tag attached to it. The tag said 6JD-18, with 18 deg pitch impeller. I talked to cp performance and they said that last letter is probably the impeller size. That would make sense but whats weird is that out of all three of these pumps, the impellers look exactly the same when looking at the fins length and shape. One of my pumps however had a bronze impeller!

Here is the impeller that came out of the pump with the tag that said 6JD-18. The impeller is the lightest of them all, it also was the crappyist when it came to casting. There are rough edges where the fins attach to the base, the surface feels rough and has deep poors/pits.

reads 14.9oz

One of the other pumps had a aluminum impeller too, this impeller is cleaner looking, feels alittle smoother and isnt as rough. I dont know if this is because sombody cleaned it up or if it's just a better impeller that was made. It also weighed alittle more.

reads 15.7oz

 

[Shaun]

continued....

Last, the first pump i bought had a bronze impeller in it! I didnt really realize this until i disassembled all the pumps. I've been worried alot about how well this pump is going to handle the HP i'm going to through at it but i've mostly been conserned about cavitation. I didnt even think that i might garnade the impeller! The bronze impeller should handle extra HP. It's also quiet abit heavier than the others.

reads 3lbs 4.2oz

Here's a comparison of all three impellers.

 

[Shaun]

Shafts & Bearings:

I have three shafts, two of them have a enclosed bearing. The bearing on these two say Federal both both have a different number on them. One of them has a number that says 1304LL and the other one says 1304FF. Not sure what the difference is. The third shaft is alot different, it looks more like a normal pump bearing and i think this is probably what is suppose to be on these because how would you greese the other two and this pump has greese fittings by the pump so it makes sense. The last bearing has the following info on it. PT Britain MH BKF 8304. The P at the beggining may be wrong, it was hard to read.

Here's the shaft with the enclosed bearing.

Here's the one that i think is the normal bearing.

Also both the enclosed bearings feel like crap when spining them, but the exposed one feels good. Not sure if it has to do with it being open and being able to get new greese constantly or if maybe this bearing just hasnt seen the abuse the others have.

 

[Shaun]

This looks like a non stock modification, maybe sombody else here knows? The intake/suction looks like sombody sleeved it, the other intake/suctions do not look like this, one thing i do like about this is that it's pretty much like a wear ring now. My bronze impeller fits way tighter in this intake/suction than it does in the original one it came out of!

 

[Shaun]

This company makes impellers for this pump from the looks of it, dont have any info on them, am going to check them out on monday

http://www.skat-trak.com/watercraft.html

 

[Shaun]

Called skat-trak today, they do make stainless impellers for them. They offer a bunch of different impellers. Give them specs on the pump and they will give you there recommendation. Guy told me the impellers run about $200 bucks.

 

[trently]

That's good info there. Shaun, I have my pump at the house with no time to tear apart (christmas crap) however looking inside I have an aluminum imp. Pump turns freely and does'nt make any noise also looks as new. As soon as the holidays finally get over I'll take it apart and figure out a plan for this little jet unit Trent

 

[trently]

Are we at the end of the info trail on these little pumps?
Trent

 

[Shaun]

I hope not, the guys over at CP were gone and now were getting close to christmas, i'll start bugging them again here after christmas

 

[trently]

That's good, I know we're all busy just wanted to get this back toward the front of the line

 

[trently]

Hey Shaun Hows it going. Did you ever here back from CP ?

 

[Phillip]

Small Berkeley jet unit
Stainless Skattrack impeller. 14-16 5 inches.

Hope this image works just wondering if this is something similar to your discussions

 

[Shaun]

That is perfect! Are you using this pump with that impeller? How much HP are to putting down to it? in what type of boat/craft? how fast you running? hows the holeshot?