For all those who have been watching my ongoing saga with fuel delivery issues here is the latest update. I checked all my hoses, fuel water seperator, fuel tank selector switch for restrictions and every thing was fine.
Clay smith pretty much told me that in order for his pump to work properly in my boat that I would need to upgrade to 1/2" I.D. hose and or run braided lines. Don't really want to do either of those at this time so I ordered an electric fuel pump to try out. I ordered the Jegs equivelent of a holley blue (holley only offered a 30 day warranty and jegs offered 1 year). Jegs told me it was bassically the same as the holley blue without the holley sticker on it.

I plumbed in the pump and mounted it as low as possible (inlet and outlet are at least 2-3" lower than the bottom of the fuel tanks). Took it out to the lake today and the pressure seemed to be better from what I noticed. Before the regulator it was about 11psi and after it was 6.

Now onto the new problem. As I was idleing into a no wake zone area in a cove the fuel pump decided to quit working. It was still running but was not providing any pressure and was very HOT. After I let it cool down for about 20 minutes with the hatch open it started rite up and was fine. I hurried my ass back to the dock through huricane like conditions praying the damn pump didn't quite again.

So did I get tricked into buying a shit pump or is this a common problem with electric pumps with an engine hatch??? Too much heat at low speeds??? I'm really at the end of my rope on this one... Running out of ideas... Seemed to have possibly fixed one problem (don't really know for sure cause I didn't have much time to play with it) and created another.

I'm running a clay smith mech. pump..didn't know they made an elec. In any case..is you're pump mounted lower than your tank?, Electric pumps don't pull to well. What kind of  fuel tanks are we talkin about here??

Are you running a fuel pump relay? or is it wired straight to the battery?

Sounds like vapor lock

I vote for a restricted or cracked pickup tube(s) too. No matter what pump you try, you problably will have the same problem. I removed my tanks and made large pickups. I have a post somewhere
where I documented it with pics. Found it.
http://www.socaljetboats.com/index.php?topic=3398.0

T.J.

that sounds like a vapor lock

If the carb vapor locks why would that effect the fuel pressure before and after the regulator  

I agree with the rest though, either the vents on the tanks (can't think they would both be bad) the pickups (again two bad one's)?  or crap in the line that joins the two tanks together. (would make more sense)  

If there is something floating around in the line it wouldn't allways have to be sealing off the line.

I would open every fitting I could to check it out.

Good luck, I hope you find something

Ultra, I know you said you don't want to do it but you have too bro, even Clay Smith said you need 1/2 hose. The electric fuel pump idea would have just been a bandaid. Think about it like this. If the Mechanical pump could make 6psi at idle (not under a load) then it can under a load with larger hoses.

I am telling you I just got finished with this same goose chase on my boat and it was an easy fix. Start by selling that electric pump to one of your buddies and go by some 1/2 fuel line and re-plumb that thing with the mechanical pump and watch the problem go away.

From what I was told the 3/8 lines are sometimes not large enough to allow and sustain a good fuel flow. I know it seems like a lot of work but it was not that hard to replace all the lines on my boat, and the hose itself was only like $60.

I really think it would be cheap insurance before you go and pull the tanks to check the pick-ups.

Good luck!

ok i dont know if i should disclose this but my boat has 3/8 lines to the tank switch and to the filter then -6 to the pump (clay smith) -10 to the splitter and -8 to the two dominators. Plugs run coco brown w/ 8 #99 jets and four 50cc squirter pumps. I know it SHOULD  be -8 from the pump back but thats the way i got it and it works for me Sooo....

I cant remember which boats it was but when I worked at the marina last summer one of the kinds of boats was prone to vapor lock, we would disconnect the fuel line and run a little fuel into a container and away they went.

I hear ya on that one, all boats are different, my boat had 3/8 lines from '76 to now, so I worked like that for a long time and I know that lots of boats out there are that way so I guess it's a one off kinda thing...

But if Clay smith is telling him to run 1/2 why wouldnt he just do it so he can eliminate that variable??? And the reason I keep brining it back up is because when I did that it fixed my problem wich was the exact same thing Ultra is describing above.

I am no pro, so all I can do is talk about what I know from experiance, ya know what I mean?

Thanks for all the replys. I appreciate it.


As far as the 1/2" line goes the reason I didn't do it is because the electric fuel tank selector valve and the fuel water seperator both have 1/4" NPT fittings. Which means even if I upgrade all my lines to 1/2" the I.D. of those fittings is only still probably gonna be 3/8" or less. I'm running a mostly stock 460, probably only about 350 hp. So I can't see how the 3/8" fuel line is the problem in my case. Another reason I went to electric is because Clay Smith said there was excessive wear on the fuel pump shaft. I'll get a pic up ASAP.

I'm thinking the reason the electric pump quite on me is because I was ideling for so long and the motor wasn't using any fuel causing the pump to overheat??? IDK???

I'll be rite back with the pick of the Clay Smith pump.

Pics. I was told this is from lack of lubrication. IDK???
This is the only pic of the motor setup I have currently. This was with the mechanical pump on. You can see the selector valve in the top left. The fuel water seperator is just below that and I mounted the pump just underneath the fuel water seperator.
 

Pics are blurry, but looks like normal markings on the pump lever to me. Wish mine looked that good! Lack of lubrication it would be worn down visibly and measureably, IMO. It's gonna get marks on it, lol, that's just kinda the way they work!.

Ray

It is a little worn down. The left side of the silver mark is definately worn I can feel the dip with my finger.

I am with Nordie. Proper venting is a big issue. When I modded my tanks I made sure I vented them seperate from cap cause with my Blower EFI motor I know I am going to pull some fuel and I do not trust the stock vent caps.

460:
 Your fuel line at the carb maybe too close to the intake and could also absorb heat. Just a thought, again the stock pickups in these things are a little bigger than McDonalds straws.
T.J.

Here is post with fuel vents.
http://www.socaljetboats.com/index.php?topic=3843.0