I bought my first jet boat a few weeks back and took it to Elsinore yesterday to test it out. Its a 19997 19.5' commander with a sportpac 454 and a quadrajet (all stock). The boat runs great and accelerates without hesitation. But when I get on it and the secondary's open it runs strong for about 15-20 seconds and then starts to die as if its running out of gas or is vapor locked. I have heard that boats with enclosed engines can have this problem so my plan is to remove the engine cover and try it out, what do you guys think? The fuel filters are new and it does the same thing regardless of which gas tank I have it running on.

Yeah, I think I will try a new better quality fuel pump with a regulator and gauge.

Thanks!

How old are the fuel hoses?

Have you cracked a fuel cap to check for a plugged tank vent?

Fuel pumps don't last forever in this garbage we call gasoline....

Good hunting.

GT

I'm gonna dive into this weekend and go through the fuel system hoses vents etc. along with fuel pump replacement, gauge and regulator. Have any of you used JEGS fuel pumps?? The price is pretty good and I want to get one with more capacity in case I end up changing the carb.

Covered engine?

I wouldn't use an automotive pump. I personally guarantee that stock deal won't exceed a stock pump. If you can find one, the dual diaphragm Carters are very nice for the scratch.


Holley https://www.summitracing.com/parts/hly-712-454-11

Carter https://www.summitracing.com/parts/crt-m60601

If you have ten's and twenties falling out of your butt, grab the billet Holley, but be mindful, you will need to regulate it...

HP Holley http://www.jegs.com/i/Holley/510/12-454-40/10002/-1

GT

Thanks for the input guys. Enclosed engine: front, back two sides a top and a bottom

Clay Smith Cams has a high flow high pressure pump, that has 1/2" fitting. He use them on every thing from blown motors, to carburator motors. Call him a call 714-523-0530.  Terry


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He really needs to grab a marine pump... Clay Smith Pumps are not marine...   


GT

At the risk of sounding ingnorant gt.,  what's the difference in the marine pump?  Ive always ran a holley 110gph on my boat,  is it just a covered engine safety thing?? 

your friendly local v-drive owner

Definition of a dumb question in my dictionary.
A question you answer while asking because you didn't think it through. 

To answer your very intelligent question, when a regular, automotive style fuel pump fails or loses a diaphragm, the fuel literally sprays out of a vent hole on the back (air) side of the diaphragm. The engine may or may not die causing an extreme explosion risk if not shut down in time.

An approved marine fuel pump has a secondary diaphragm and a vent port designed to be routed to the throat of the carburetor. In the event of a failure of the diaphragm, the fuel is pushed via the second diaphram in the sealed unit up through that port killing the engine. Eliminating the cahnce of a fire or explosion.

Hope that paints a picture for you....

GT

Got it!!  Carter double diafram,  sorry got ahead of myself..  Thanks gt.. Or holley billet👍👍

your friendly local v-drive owner

I have a spare Carter fuel pump you can use to test to help narrow down the issue in in west covina

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Thanks for all the input and suggestions! I have ordered an new carter marine fuel pump from JEGS that's what my marine power motor came with. I have also ordered all new fuel filters and hose. I'm thinking it might be the placement of the fuel pump though. Its basically mounted next to the dizzy on a bracket hanging off the intake manifold, that's the way marine power did it. If I still have the same issue after all the new stuff mentioned above is installed I will relocate the fuel pump low on the transom. I will be sure to post the solution when I get it to try to help others that run into this issue. Thank you for offering the tester fuel pump 5150 whiteboy! 

So you have an electric pump....

I had the same problem with my boat. Check the fittings that come off the tank. Mine had screens in them and they were clogged so as soon as i wooded it, it would dies

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Problem solved. I changed the fuel filters and replaced the fuel pump. I'm pretty sure it was the pump and not the filters because it did the same thing regardless of which tank I was pulling from. Tested it at lake Elsinore yesterday and it ran perfect. Thank you for help!

Yeah, fuel pressure gauge is on the LONG list of things to do before summer lol