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.
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
Just wondering how big is the boat? 19' 21' ??
Welcome to the boards!!!
[ May 06, 2003, 01:08 AM: Message edited by: NeoBurn ]
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).
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!
[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
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.
Did someone ask for pictures?
Click on a picture for a bigger version!
[ May 06, 2003, 10:18 AM: Message edited by: Snorider ]
And the final four:
(Click to zoom again)
[ May 06, 2003, 10:21 AM: Message edited by: Snorider ]
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
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
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