I need more holeshot! I have a 1991 19' Caribbean with a Berkely pump, place diverter, A impeller, and stock 333 HP 454, and thru transom exhaust. The carb is a 650 Holley with vacuum secondaries (and I have experimented with the spring kit--not much difference). I have a low profile, single plane, spread bore pattern intake manifold matched to a standard pattern carb with an adapter. The timing is advanced slightly to improve throttle response. The jet pump has never been blue-printed; it has no leaks and no slippage. I presently top out at around 55-60 mph (not GPS) at around 4700 rpm. I do not mind losing some top speed for an improvement in holeshot. My mechanic says I should be able to pull up two single-ski skiers with not too much problem--but the boat has a tough time popping out one skier. I don't want to spend very much money--I want to stay away from a cam change etc. Would a dual plane spread bore intake manifold matched up to a 650-700 Holley double pumper (with matching spread bore pattern) do the trick? Or do I need a different impeller? Or both? Help!
I would do the following 3 things to your pump.
1) Blueprint your pump
2) For hloie shot got to bigger impeller AA
3) Install DPS impeller loader
If you do the above things to your pump you will have a hole shot.
Call Jim Brock @ (818) 890-1687 he will steer you in right direction.
SpectraBrent
Thanks SpetraBrent--I'll give him a call.
I think I'd check your setup over carefully first. You should be able to pop 3 skiers out of the water with your current setup. Check you carb and make sure that when you hit the throttle you're getting a good healthy shot of gas in the primary bores. You don't even have to start the boat for this one. If you're primary squirters aren't working check the accelerator pump diaphragm and make sure it isn't ripped. Check to make sure the squirters themselves aren't plugged. You may want to consider changing them for a larger size but the stock size is usually fine for a stock motor such as yours. I've got an 18.5 footer with a stock 460 Ford and it'll rip your arms off on a ski take off (if you've a mind to). I wouldn't change a thing without checking everything you currently have to make sure it's working properly!
You didnt say in your boat description if you have any kind of intake grate the boat. Well worth the 65 or so bucks and will help your holeshot for sure. Good luck.
Carribean
You didn't say what your motor is doing when you punch it. Is it missing? Is it dogging out? Running smooth and just no power? With all due respect, I wouldn't start rebuilding pumps that don't need it, and I quote you "it has no leaks and no slippage". I'd hate to see you throw your money away on shotgun repairs. Hell when I first got my boat the pump was shot and it still pulled a 225 lb skiier (me) up with no problems. If you want and excuse to modify just do what everyone else does (cause they wanna) If you just wanna be able to get a skier out of the hole, check your current setup. Nobody is going say that my stock Ford BB has more power than a stock Chevy BB are they?
I'm with ya Squirtcha?. Rule out the lowbuck stuff first. Process of elimination. Do you have a healthy accelerator pump squirt? Hook up your timing light and make sure the mechanical advance weights are working and haven't rusted themselves in place. It happened to me on a HEI Chevy. Maybe get a fuel pressure gauge too.
Originally posted by MoJetBoPar:
I'm with ya Squirtcha?. Rule out the lowbuck stuff first. Process of elimination. Do you have a healthy accelerator pump squirt? Hook up your timing light and make sure the mechanical advance weights are working and haven't rusted themselves in place. It happened to me on a HEI Chevy. Maybe get a fuel pressure gauge too.
I don't care for single-planes much on a heavy boat. They require more pump shot to fill the hole. Too easy to create a big sag at low-end
Squirtcha,
Thanks for the help. I'd love to pull two or three skiers up! I'll check into what you suggested--it makes sense. When I punch the motor it goes--but with hesitation under a load like it is hungry for air.
Thanks,
Caribbean 19'
[This message has been edited by Caribbean19' (edited February 01, 2001).]
ChetC-I just have the stock grate--nothing special. I will look into something better. Thanks!
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