New to jetboats - hi all

[Snorider]

Hi, just bought a jetboat and love the forums! Seems like there is a lot of useful info here!
Here is what i bought:
1978 Sleekcraft Kaui (i think thats how you spell it)
460 Ford Packajet, 12JC-A pump w/ jetovator
Currently, it will do 62mph @ 5400 - 5500rpm
Seems like someone did some work to the motor, but not really sure. After reading the forum topics about the oil problems with the 460's, it kinda made me wonder about whether it was healthy for me to beat the boat that hard :p
Got it about 5 days ago, and i have been running it at WOT for about 10minutes nonstop each time i took it out - and so far, there havent been any problems. The guy i bought it from was running 20w50 synth., so thats a good thing.
And the fact that the water temp of the lake is a brisk 45F, that is prolly helping to keep it cool.
The thing has plenty of oil pressure, (80+ lbs @ wot) - so much that it will slowly seep out of the PCV valve - which makes me tend to believe what you guys say about the oil stayin in the heads.
Since it still has the points / condenser distributor on it, i am probably gonna switch it to HEI - any recommendations? I was thinking MSD.
Also, is switching to a 12-JI worth it? will i notice a speed increase? Just like everyone else, i want 70+mph :D
It doesnt have a place diverter (since its a JC model), and i dont know what impeller is in it.
[ May 04, 2003, 09:39 PM: Message edited by: Snorider ]

[HBjet]

Snorider:
Currently, it will do 62mph @ 5400 - 5500rpmWelcome to the boards!
First thing I would check is either your pump, or your RPM gauge. If you have an A impeller, I would say your in need of a pump rebuild because that RPM is really high. And did you GPS the boat, or do you have an MPH gauge too? I only ask because that MPH might not be right if you didn't use a GPS.
I would have your pump checked out before you decide on replacing it. A basic rebuild may be all you need.
HBjet

[HammerDown]

Welcome to the Maddness...I agree with HB said...I would look to see what size Impeller you have, with those rpm's you should be going faster...GPS is the best way to tell that, if its a smaller cut (B)or (C) and the pumps tight I'd up to a larger size. However if the pumps loose and there's a full (A) in there, just do a rebuid. The Impeller is usually stamped with the Impeller cut. HOWEVER that may not mean it wasent already trimed down.
Where at in Pa. you from? I'm in the Plilly area, or just south of the city.
PS. there's a great Book by Seloc Publications titled "Marine Jet Drives". It's all in there.
[ May 05, 2003, 06:33 AM: Message edited by: HammerDown ]

[Snorider]

The guy i bought it from just rebuilt the drive (or at least he said he did), and gave me about 6 gaskets for the drive as well. I used the in-boat speedo to get 62mph, but I would guess that the boat is doing anywhere betwen 58-62 on GPS judging by how it runs against other boats.
Is there any way to see what the impeller is without taking the bowl out?
Again, thanks for all the great info!
The guy i bought it from told me it has cobrajet heads on it, i was planning on looking for a casting number today, just to verify. From what ive heard, they are decent heads to have though.

[Snorider]

HammerDown:
Where at in Pa. you from? I'm in the Plilly area, or just south of the city.
Northeast - up near Stroudsburg and such. If you look at a map, im on lake wallenpaupack; I think its the largest manmade lake in PA???

[Ranz1]

Welcome Snorider, This board is GREAT for info and parts. I have only owned my CVX20 for about year and a half and i have leard soooo much about jets ,engines, carbs, hulls, ect. People help if you if you need a parts that they got. I plan on hitting Lake Wallenpaupack this year. Will hook up. I boat in Swinging Bridge Resevere, in Monticello. You should come out ther some time. Also that book that Hammerdown talked about is great... Anthony

[HammerDown]

Snorider:
The guy i bought it from just rebuilt the drive (or at least he said he did),
Is there any way to see what the impeller is without taking the bowl out?
Impellers are stamped on the back side(bowl must come off)...how about contacting the seller and asking him...If he rebuilt the pump, he should know.

[Snorider]

I tried that already - i asked the previous owner and he didnt know. He was able to tell me that it was the stock impeller, so whatever came with a 460pacakjet is what i got, most likely a B or C.
I should probably upgrade to a stainless impeller, considering right now its turning 5400rpm and the previous owner estimated the motor at 425hp.

[Hotcrusader76]

Welcome aboard! This is the next best adventure to joining the military.
~Ty

[Bense468]

Something is not right there. I would definatly look into it. You should be getting more speed out of that kind of rpm. The numbers are just not working out. My guess would be that you are running a "b" or a "bc" if the pump was just re-built. If it is an A the guy is stroking you and it needs re-built.

[zigspi 1]

hey snorider , you really should be running 68mph
with those rpms . you might need a rebiuld or something just doesnt seem normal to be running those rpms . I run the paupack , Iam in the scranton area. :cool:

[sidewound]

Welcome to the mayhem,
When I bought my boat I was assured by the owner that the pump had been recently rebuilt with lotsa cool shit. I'm in the middle of a MAJOR rebuild right now. So much for the sales pitch. Guess I'll always be a dumbass.
Your doin better than me. Yours is up.
Peace Man
CESAR

[NeoBurn]

Just wondering how big is the boat? 19' 21' ??
Welcome to the boards!!!
[ May 06, 2003, 01:08 AM: Message edited by: NeoBurn ]

[Rexone]

Welcome Snorider,
From what you've stated I like others suspect you may need a pump rebuild (excessive RPM / speed ratio). You don't need a stainless impeller in your power range, just the proper size aluminum impeller and proper clearances. Large clearances are typically what produce excessive RPM without corresponding speed or you might have a small impeller or a combination of both.
Also "most" cheaper pressure type speedos are inaccurate on the "fast" side.
Have fun here, there's a lot of good pump guys on the forum (who know way more than myself on the detail end of things). :)

[76 Sleekcraft]

Hey Man, welcome!
I too, have a Sleekcraft Kauai. 460 ford, berkeley etc.
Just had the pump done, and the engine is going back together as we speak. You should enjoy the boat, Mine rides good and is a blast.
Just remember, no matter how much you spend on speed, there is always someone faster!
Good luck,
lets see some pictures!

[058]

[QUOTE]Originally posted by Snorider:
[QB] Hi, just bought a jetboat and love the forums! Seems like there is a lot of useful info here!
Here is what i bought:
1978 Sleekcraft Kaui (i think thats how you spell it)
460 Ford Packajet, 12JC-A pump w/ jetovator
Currently, it will do 62mph @ 5400 - 5500rpm
Seems like someone did some work to the motor, but not really sure. After reading the forum topics about the oil problems with the 460's, it kinda made me wonder about whether it was healthy for me to beat the boat that hard :p
What oiling problems would that be with a 460? All thats needed to be done to the oiling system for jetboat use is a 10qt. pan spec. for jetboat and the proper pick up. I run 2 different 385 series engines in boats and spin them 7-7500 rpms with minimal oil mods, H.V. pump, 10qt. pan with the proper pick up, extra bearing clearance and thats about it. I don't think 5500rpms would be any problem for your engine.

[Snorider]

Did someone ask for pictures?
Click on a picture for a bigger version! :D
http://www.1stklas.com/boats/jet/jetboat_0.jpg (http://www.1stklas.com/boats/jet/P1000853.jpg) http://www.1stklas.com/boats/jet/jetboat_1.jpg (http://www.1stklas.com/boats/jet/P1000845.jpg) http://www.1stklas.com/boats/jet/jetboat_2.jpg (http://www.1stklas.com/boats/jet/P1000846.jpg) http://www.1stklas.com/boats/jet/jetboat_3.jpg (http://www.1stklas.com/boats/jet/P1000847.jpg)
[ May 06, 2003, 10:18 AM: Message edited by: Snorider ]

[Snorider]

And the final four:
(Click to zoom again)
http://www.1stklas.com/boats/jet/jetboat_4.jpg (http://www.1stklas.com/boats/jet/P1000848.jpg) http://www.1stklas.com/boats/jet/jetboat_5.jpg (http://www.1stklas.com/boats/jet/P1000849.jpg) http://www.1stklas.com/boats/jet/jetboat_6.jpg (http://www.1stklas.com/boats/jet/P1000850.jpg) http://www.1stklas.com/boats/jet/jetboat_7.jpg (http://www.1stklas.com/boats/jet/P1000851.jpg)
[ May 06, 2003, 10:21 AM: Message edited by: Snorider ]

[OMEGA_BUBBLE_JET]

welcome... As far as oiling problems with 460. they are non-existing. You might be thinking of the 455 olds motor. If you have true cobrajet heads the casting number will be d0oe-r. They are good heads but maybe a little overkill for a mild build. they are really for radical engines. they could work well. my guess is you don't have them seeing how rare they are. you probably have d3ve-a2a heads or dove-c's. neither are bad heads. quick test on the pump. pull the hand hole cover and grab the shaft firmly and try to shake it or move it. if it has any play whatsoever in it you need a rebuild. You definitely are spinning too high for the mph. Don't feel bad though I bought a boat with a FRESH pump and had to go through it first season. Important thing is you got a jet boat and a huge pit to throw money into. enjoy it and feel free to ask any questions. these guys are great. As far as your distributor. an HEI distributor is a GM thing. You need a unilite (made by mallory). if you ask around the boards i'm sure someone has one for you. Good luck chief

[Jim Hall]

I to had a problem with rpm's being too high for size of impellor. I rebuilt pump used Aggressor B
Ultimate wear ring and installed Weiand Stealth manifold on mild 460 and still my rpms too high for speed. After pulling hair out and reading through all the boards I decided to purchase a new tach and see if maybe problem existed elsewhere. Bingo!! that was it. Now tach reads 4400 @ 58mph... my original tach was pegged @ 6000,1600 rpm's off.Changing the tach out or getting it recalibrated would be the easiest and most cost effective. Just my 2 cents worth

[Brknrun]

Hey welcome to the forums..I see you said you were from Stroudsburg Pa..Were did you go to high school..I myself went Pocono Mt..and grew up in Bartonsville....

[Snorider]

Brknrun:
Hey welcome to the forums..I see you said you were from Stroudsburg Pa..Were did you go to high school..I myself went Pocono Mt..and grew up in Bartonsville.... I went to pocono mt schools for 10 years, then went to wallenpaupack area for my final 2 years.
Why would you want to move to Calif from PA? Its just downright hot out there :confused:

[Brknrun]

I came out to Calif through the Marine Corps..
I love Calif,but after a while the fast lane starts catchin up to ya and you have to move over..that is if you can even get there with all the traffic out here..From the pictures it looks like you live on a lake?Is that Walanpaupac?I'm also curious what year you graduated?
[ May 07, 2003, 07:06 PM: Message edited by: Brknrun ]

[Snorider]

Brknrun:
From the pictures it looks like you live on a lake?Is that Walanpaupac?I'm also curious what year you graduated? Yea, its lake wallenpaupack; and i graduated in 2000. Im still in my 3rd year of college though.