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Regarding oil vs Grease in Berkeley bowls 12/12/09

"Had my berkley 12 jb pump rebuilt and where
you put gear oil in the bowl he put a grease fitting. Is this better
or should i just put oil in it?"

Although somewhat redundant to what been said above ,the true "grease
lube bowls" have little to no "reservoir' as such and they typically
have a grease seal retainer snap ring in front of the shaft/bowl seal.
Some grease lube bowls even have a double snap ring retained seal.
When a true grease lubed bowl is lubed thru the tail shaft  plug zerk,
a small amount  grease is forced into and around the shaft and
bushings . When a Berk type bowl is "retro grease lubed" the process
depends on pumping enough into the old oil bath cavity to finally fill
the Oil void  and hope that the grease will eventually find its way to
the shaft and bushings allowing for air pockets and hoping the front
seal isn't hydraulically "jacked out" in the process . IMO its best to
keep oil in the Berk oil lube bowl to start with and frankly I don't
understand why one would routinely convert from oil to grease as a
matter of course ? :unless for what ever reason the Berk bowl as
"designed" , will for some reason no longer hold oil and one wishes
to make use of it (the bowl despite that existing problem ),this could
result from a multitude of reasons for example if the bowl has
suffered a "spun" tail shaft bushing failure that required line boring
and sleeving, small cracks, casting defects or its a purely "economic"
thing (shaft score in the seal area or etc ...)  . That said once a
Berk bowl is filled with grease (which is quite a bit) as yours is and
then reinstalled you might as well leave it. To extricate all the
grease or even the majority of it if lucky is a arduous task requiring
heating warming , thining and diluting the remaining "sticky" (likley
"hi temp") grease to the point of cleaning and draining same from the
bowl oil cavity (not fun) . If this was to be done the time to do it
was when the bowl was stripped down for repairs or overhaul . Heres
the good news , most pump kits and repair parts/replacement bushings
in use are modern coated self lubricating (ptfe) and will pretty much
run and survive in anything grease water oil etc as far as oil
"carrying of heat" the bowl is constantly bathed in and bombarded with
cool water creating a pretty efficiant heat "sink" ;) just my 02  Tom @Jet boat Performance

Join Date: Mar 2008
Posts: 29
 10/18/09 (answer to a jet boat carburation inquiry)

Don't worry about the carburetors being too big, in a jet boat it won't use what it doesn't need. If your running a pair of 600's i'm gonna guess they're are vacuum secondaries in which case you'll run off the primaries until the engine demands more. and also don't worry about the High RPM's advertized with the TR, it simply means the tunnel ram was designed to make maximum power within that range, Also any torque loss on the bottom end most likley would never be realized in a jet boat unless you are running a large impeller.

A properly tuned pair of caburetors should'nt have much worse fuel economy over a single properly tuned carburetor. I would say they should have the same economy if not for two accelorator pumps pumping in unisinc on a dual set up. Eceptions being the 660cs which have no power valves and are about 8 jet sizes too rich until until you put your foot in it, but these carburetors were designed with WOT in mind, not part throttle cruising .

Typically, when an engine is thought to be over carbureted more often than not the carburetor is impropperly tuned. And most often the lack of economy that follows is due to overly rich idle ciruit, improperly adjusted throttle blades (too far into the transfer slot) or power valve selection. When set up correctly a 600 should flow the same desired ratio of gasoline to air as and 850 with the 850 having a potential to flow significantly more volume if required.

I guess my point/opinion is:
A. More is better, dyno testing(not mine) has shown you can make more power with a bigger carburetor in alot of cases
B. You can achive approximatly the same GPM (Gallon Per Mile) ratio with a smaller carb as you can with a larger PROPPERLY TUNED carburetor/s/engine
C. If i didn't believe what i was saying i wouldn't be installing an 1100+ Dominator on my 408cid engine


2/15/09 This was a forum answer in response to a question regarding choices in impellers and loaders for a Glaston CVX 23'

....................................................................................................................................Most modern oem Impellers are rated to 450 hp, not sure about my competition but ours are good up to 500 (although i have knowledge of folks running aluminum much higher hp I don't condone it) I still would go with a AA in your application , for the lift factor and hole shot gained by a bigger impeller in a bigger boat . regarding loaders lots of boats benifit from them ,heavier boats IMO dont always (my Miller runs 80 with a rock grate& AAA imp) , the single best way to add or subtrcat "hardware" to your jet is the scientific way , this means drilling and tapping the jet (suction hsg ) in two places minimum to derive readings to actually observe and know whats taking place in the jet underway not unlike your engine guages . This is cheap and easy and gives you at minimum ,some kind of reference to make decisions by. To simply bolt on a loader or shoe etc and "call it good" is akin to throwing darts at a dart board ,I wont deny that one can get lucky . I suppose inlieu of that one could borrow an arm load of loaders and go to the lake trying different and experimenting with ones , this is arduous and time consuming and as loaders for example have to be checked/trimmed/tuned to the bottom of the boat ,just doesnt make sense. heres the set up were useing on our Glastron , although these are marshall liquid filled , a pair of inexpensive oil pressure guages can be employed, lines and fittings are hardware store stuff! If  were to make 1 change to an "E" pump boat carte blanche it would be to the "shoe" area which we know is deficiant up front ! knowledge is power ! Tom

note the small lines on the right of the suction near the hull



Regarding Loaders: No one Jet drive intake loader is a "panacea" (end all be all) One boat ,one impeller,one jet and one combination different uses and applications may like one type of loader better than another  No two boats and setups are neccesarily exactly alike. There are only base lines IMO and to some degree "experimentation" will be neccesary to find what works .The most critical thing is that the loader doesnt "impede" performance and that its  "trimmed/tuned" & correctly "secured" to the boat and  , the hull and the "shoe" Not all boats even need a loader just my H/O/P   Wink Tom

regarding   take off "Pulling" issues and complaints ,if its on accel it probably relates to nozzle/steering "dragging hardware" is it an Aggressor diverter ? they tend to do that , pull on hard or sudden decel is an "underwater hardware" concerns ,the first is annoying the second is dangerous ! Bang Head

All that said heres our new loader offering  Wink


12jc Berkeley "splitbowl"


Heres our JBP Berkeley "C" split bowl conversion , professionally modified to "split bowl" , doubled drilled on the exit side , new tail shaft bushings, shaft seal,bowl plug  and shipped with bowl gasket $425.00 plus UPS and tax in CA .Please call or PM for details more pics to follow Thanks Tom

November 15, 2008 - Saturday

Berkeley vs Dominator (from a forum post)  (from a forum post Berkeley vs Dominator)


The two Basic jets (12 jg/c Berk and Dom 12s) are very similar and many parts interchange between them  Some diffences like Omar said are wear ring shoulder size and design and the grease slinger behind the frt bearing . With the exception of the very early Berks (12 A&B) ,all Berk 12j  models including the E&F use virtually them same parts for repair . Dominator has "morphed" periodically over the years ,making changes to wear ring OD sizes and designs . Rebuilding the large number  jets as we do find there are "pitfalls" and its critical ,for example on Dominator to know serial s for parts replacement accuracy. Omar is also correct on the "water lube" brgs on early Dom jets , now they have a snap ring retained double greasable seal vs Berk which uses a 90 wt oil reservoir. Lots of other jets (Aggresor, Legend A/T,Bayjet) and thier parts will also "swap" between each other but sometimes have fit and tolerance issues to be aware of sometimes requiring modifcations, lathe and mill work . Most of these Jets will all bolt to the others suction pieces (even Bayjet with some work ) As far as Pure strength goes ,my weapon of choice among them is always Dominator for its casting design and thickness on the suctions and bowls . Dominator/AT also is a company who is always "moving forward" working on new products and improvement , we use/install alot of the Dominator HP intakes and although the desing is not all that much diffenrent than the original Berk we find it a beautiful piece and "cake to install and set up . A Dominator 12s with a 17-4 shaft and Stainless impeller with hold up to Mega HP with very few other Mods . More info if you need or want it Tom@JBP
authorized Dominator A/T dealer


November 11, 2008 - Tuesday

more about Jet Boat Performance

To those who visit this blog and our my space pages please check out out sales and entertainment web sites at www.jetboatperformance.com  www.jetboattech.com  www.jacuzzijetdriveparts.com www.jetdriveconversion.com  please post comments or questions here or send them to jetboatinfo@sbcglobal.net Thanks JBP



Berkeley Jet bowl info

This is reposted from a forum: regarding Jet drive "split bowls"

 All "split bowls" "A" ,"B" and "G"  are very similar although I prefer the G design when I can get my hands on one. A's and B's are the very early 60 and 70's and work OK (look carefull for cracks) Those will all facilitate "bolt ons" (droops , wedges) ,straight snoots etc Modified "C" bowls (exit hsg tail removed and flange installed) ,will do this as well . Theres also a plethera of really nice after market Split bowls like A/T Dominator and Aggressor 7's 9's and 11's and Legend ,most will be a direct bolt up to your berk , some like late AT and Legend will have some subtle design "sealing" differences , for example Dominator OD is larger and needs a different transom adaptor (if used) Energizer bowls have  different bolt patterns Legend bowls have diffent exit side bolt patterns etc Bowl internal designs vary quite a bit  Tom


October 31, 2008 - Friday

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Jet Boat Performance is a family operated entity located in Atascadero California specializing in Parts and accesories for Jet boat and V-drive boats from the 60's 70's 80's 90's and current . We ship quality parts and accesories world wide daily . We sell every imaginable part piece and accesory you could want for these boats . We also offer quality Engine and jet drive repairs and blueprinting as well as general service and maintenance. We have a large supply of qualiy used parts . We offer polite friendly tech help and advice and information ! We are not just someone on the other end of a phone taking orders , we are boating enthusiast who eat sleep and breath this sport . We can be reached 10 am to 6 pm at 805 466 4719 or visit our web site at www.jetboatperformance.com   email  jetboatinfo@sbcglobal.net

Please Watch this blog for future articles and photos of our "reader rides and event photos.... Best regards boat and play safley Tom


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