Please Help... i need advise!

[NescherMonty17]

I have purchased a 74 sleekcraft, with a small block 350 out of a van. The boat has a Berkeley 12JC, with what im told is an "A" impeller.  I bought an edelbrock intake and carb from oriellie's thinking it would work, but am needing a marine carb. Also needing Marine fuel pump, flywheel cover, starter, and flame arrestor. 

The boat as it sits works, however only gets up to about 35 mph. and at 3/4-4/4 throttle it "falls on its face" and stops accelerating.

I have found a marine edelbrock 1410 750 cfm carb, and would like to know if this is too much carb for a stock car 350.
do i need to do a cam swap?? if so, with what cam?
is the  "A" impeller the correct impeller for my application?

im seeking advise on what i need to do next... and im anxious to get it working quickly, due to time already spent messing with it lol.

here is a link to the original topic i started on a diferent forum.  has a lot of pictures of my incomplete motor.

http://www.performanceboats.com/jet-boats/102316-seeking-wisdom.html

hurry.gif

 

[KONA77]

does your boat have a covered engine?, 

 

[NescherMonty17]

yes it does, and i have installed a blower, and vented the engine cover the best i can.

 

[KONA77]

then yes you need a marine carb,  etc.....  not sure about the carb size you've chosen,  seems a little big,  but carbs tend to perform differently on these boats that than on a car...

 

[duanehydro]

A jet pump is like a big dyno....takes a lot of torque to spin the impeller...a stock 350 would have a heck of a time turning 4000 with a tight A impeller. Suggest adding horsepower (bbc) or changing impellers. (i.e., I wouldn't spend the money to buy the special marine parts for a small block. They are relatively expensive, however, if you are stuck with a small block, cam change as well as impeller change with a good intake and carb would be my first changes.

 

[duanehydro]

And fwiw, I wouldn't put a edelbrock carb on my lawnmower. :smile26:

 

[Devilman]

I would also add that until you do end up with the proper marine stuff for the engine (starter, carb, dist., flame arrestor, etc.) I would not run it with the cover on the engine. You can get away with "car" parts on these things with an open engine compartment, but on a covered engine compartment, that is asking for trouble.

The falling on its face deal, could be trash in the filter or carbs? What carb is on it now, an Edelbrock? Some say they are not the best choice of carbs for a jet boat, not sure if I ever heard why. Edelbrock carbs are pretty simple to take apart I had one on my Camaro that used to get trash in it from time to time. I'd take it apart, clean everything out with carb cleaner & air, put it back together & she'd be good to go again.

 

[spd500]

think.gif So should I take the engine cover off of my pickup truck until I get the proper carb for running under an engine cover  :smile21:

 

[Devilman]

And fwiw, I wouldn't put a edelbrock carb on my lawnmower. :smile26:

I was just posting about that. I have seen it posted before, but nobody ever sez why that is. Sooo why is that? :huh:

 

[Devilman]

think.gif So should I take the engine cover off of my pickup truck until I get the proper carb for running under an engine cover  :smile21:

Now you know better than that, but nah.. feel free to blow yourself.... up. lol :grin:

 

[spd500]

And fwiw, I wouldn't put a edelbrock carb on my lawnmower. :smile26:

I was just posting about that. I have seen it posted before, but nobody ever sez why that is. Sooo why is that? :huh:

Because they always end up to be junk  :smile30:

 

[NescherMonty17]

ok so here is my problem... what impeller do i need to be running? what cam would u suggest, what carb would u suggest...  I have a big block 454, however it is in a winebago right now, im not sure it runs, and it is all car parts as well...

im aware of what mistakes ive made with car parts, and that i will probably blow up, so i need to fix it, and this is all i have, car parts.  id be willing to buy some new stuff... but nobody has been able to tell me what i need... i need to stop wasting money and be smart about this... ive spent too much already and have made 0 progress.

 

[John]

if its in a RV its a truck block which is what most marine engines are based off of marine block so you should be good to go ..................if it runs

 

[spd500]

Guessing by the pics in your other thread the engine cover is not original to the boat anyways . Why not take it off and get the big blocdk running right with normal parts and then start worrying about finding the stuff to switch over to parts for under the cover after you get it on the water and get all the bugs worked out ?

 

[spd500]

Half of the boats around here had engine covers at one time , or at least an option to order them with a cover . It is not needed to run and enjoy your boat . I would ditch the cover at least for now .

 

[KONA77]

for a cruiser that is making 330 hp or more then the A impeller is ok,  if not drop down to a b or c,    Berckly has a hp vs impellar chart at their website

 

[John]

And fwiw, I wouldn't put a edelbrock carb on my lawnmower. :smile26:

I was just posting about that. I have seen it posted before, but nobody ever sez why that is. Sooo why is that? :huh:

carbs get hot boil the fuel out of the bowls then you have a compartment full of air and gas vapors, turn the key and boom!


thats why



i think he wants to keepthe engine cover cause he wants to pull skiers, not go on booze cruises like all of yall

 

[Last Mohecian]

Glad you made it over here. One thing you have to realize is there is no simple one size fits all answer. There are plenty of small block jet boats out there. Not near as abundant as a big block but they do exist.  This is not gonna be a situation where you get it all sorted in a week.  If your goal is 50 MPH and reliable that can be done with a small block. As for the marine parts, just remove the engine cover for now and sort out the other issues.  Have you put a fuel pressure gauge on it yet and monitored the fuel pressure while under way?  Have you done a basic tune up with new cap, rotor, plugs and wires?  The guys on the boards can help but you gotta give them time and information. I understand it is frustrating.  I promise if you give it a little time it will be worth it.

 

[spd500]

Does the tow rope for the skier connect to the engine cover  crazy.gif Some of us still pull tubes and skiers without engine covers  :smile26: I hope I don't get a ticket for towing people with an uncovered engine  think.gif

 

[NescherMonty17]

Guessing by the pics in your other thread the engine cover is not original to the boat anyways . Why not take it off and get the big blocdk running right with normal parts and then start worrying about finding the stuff to switch over to parts for under the cover after you get it on the water and get all the bugs worked out ?

i would love to do that, however, i dont have any thing to mount the BBC in the boat, nor do i know if it will even fit.  i dont have exhaust, im not sure the pump will attach, still am going to need a carb, and intake, and water neck... all of the above... sounds cheaper to beef the 350.

yeah and nothing is original. but idc i just want it to work. cheaply. and safely.lol