SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: propless on December 10, 2007, 08:56:59 PM

Title: Fuel pump ?
Post by: propless on December 10, 2007, 08:56:59 PM
   I'm haveing a strange problem  ??? 

  I have a Holly blue fuel pump with a seperate press regulator set at 5 psi. When I turn it on it will hold 5 psi (on the gauge) for about 2 min, than you can hear the sound of the pump change and it pegs the gauge to over 10 psi (the gauge only reads up to 10). If I switch it off and back on it goes back to 5 and starts all over again .  :(  I tried clearing the regulator (sprayed it with carb cleaner), no change   ???

 Its plumbed like this, tanks - switching valve - pump - filter/water seperator - regulator - motor. The regulator is also Holly and looks like a T, inlet on the bottom - adjuster on top - left side out to motor - right side to gauge .  Is this right ?
Title: Re: Fuel pump ?
Post by: Blue on December 10, 2007, 09:13:02 PM
I gave up on electric a while ago and went Clay Smith mechanical for around $100ish.  One less thing to worry about and the Clay Smith is the best built.
Title: Re: Fuel pump ?
Post by: GAWnCA on December 10, 2007, 09:53:10 PM
ANyone ever seen or used one of these?  http://www.racepumps.com/index.html  Costs more.
Title: Re: Fuel pump ?
Post by: Ralph Brunt on December 11, 2007, 06:42:58 AM
ive gotta go with blue on this one clay smith is the only way to go, that being said ive went through many holley blue's and what ive found its just not worth the hassle, and most of the time its the regulator that comes with them thats the problem. i switched to a mallory reg there a little pricey but worth the peace of mind to me
Title: Re: Fuel pump ?
Post by: Heatseeker on December 11, 2007, 07:25:00 AM
Another Clay Smith vote here! Mechanical pumps have been used reliably in autos for many years. The Clay Smith pump can deliver sufficient fuel volume to all but the most demanding engines and it self regulates(to a point). And they're silent ;) .

I've had zero fuel delivery issues with mine. It's been running for 5 seasons.
Title: Re: Fuel pump ?
Post by: GAWnCA on December 11, 2007, 07:32:34 AM
So what determines the inlet/outlet size?  You say it regulates to a point?  At what point do you need a regulator on a carbed motor?
Title: Re: Fuel pump ?
Post by: FORKEDUP on December 11, 2007, 08:15:03 AM
never had a problem with my holley blue pump, one of the lucky ones i guess :)
Title: Re: Fuel pump ?
Post by: 2savage4you on December 11, 2007, 08:27:29 AM
So what determines the inlet/outlet size?  You say it regulates to a point?  At what point do you need a regulator on a carbed motor?

The Holley Blue pump puts out 110 GPH @14psi And the normal carb only allows 7psi so it has to be regulated to the carb.   It will actually fill your crankcase full of fuel really quick and hurt the carb ;) with no regulater.
I think thats correct ???


2sav
Title: Re: Fuel pump ?
Post by: FORKEDUP on December 11, 2007, 08:34:12 AM
The Holley Blue pump puts out 110 GPH @14psi And the normal carb only allows 7psi so it has to be regulated to the carb.   It will actually fill your crankcase full of fuel really quick and hurt the carb ;) with no regulater.
I think thats correct ???


2sav

I think he was refering to the clay smith self regulating to a point ???
Title: Re: Fuel pump ?
Post by: GAWnCA on December 11, 2007, 08:40:30 AM
I think he was refering to the clay smith self regulating to a point ???

That's what I was talking about.  I don't want so much fuel going to the carb it can't handle it.  So how do you get he pressure down to a safe psi level?   I've got a brand new Holley marine that came with the regulator and I'm thinking about sending it back and going mechanical.

I guess I can order the Clay wit the 1/2" in/out lets and then reduce it if I need to, to 3/8".
Title: Re: Fuel pump ?
Post by: propless on December 11, 2007, 08:45:09 AM
 Thanks for the info guys, but I cant use a mech pump ,   I "forgot" to mention this is on the 2 smoker  :-[.  So should I replace the regulator ?

 My jet boat has a Carter elec pump = no problems.  EVER !
Title: Re: Fuel pump ?
Post by: GAWnCA on December 11, 2007, 08:51:28 AM
never had a problem with my holley blue pump, one of the lucky ones i guess :)


Well, I've got a new Holley blue pump with regulator sitting here, maybe I should just go ahead and hook it up.  A lot less hassle, except for locating it and running the fuel lines and then there's the over flow port that has to go somewhere.
Title: Re: Fuel pump ?
Post by: UNDONE on December 11, 2007, 08:58:58 AM
In all three of the carbed engines I've had I had the regulators set at 14.

Had the BG 400-2 and the BG 2 port plus reg on my old truck. Worked well, The fittings I ordered came in the wrong size. The one fitting marked 1/2" was actually 3/8" when I put the micrometer to it. So I sent it back to BG and waited for 2 weeks to get the replacement, which was the right size. 4000 miles and a year later never had any problems.
Title: Re: Fuel pump ?
Post by: FORKEDUP on December 11, 2007, 09:21:01 AM
mine doesn't have the overflow port ???, is it because it is not a marine application pump ???
Title: Re: Fuel pump ?
Post by: GAWnCA on December 11, 2007, 10:32:53 AM
mine doesn't have the overflow port ???, is it because it is not a marine application pump ???

Guess not as this is a marine pump and regulator.  If you look at the middle of the pump and down by the base you'll see the overflow tube.  I think it's suppose to be plumbed to the top of the carb.

(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fgregaw.home.comcast.net%2FP-n-R.jpg&hash=2331a10d52a443f5dd3574ed6c66705f28021877)
Title: Re: Fuel pump ?
Post by: UNDONE on December 11, 2007, 12:13:25 PM
it is supposed to be plumbed to the top of the carb...
Title: Re: Fuel pump ?
Post by: GAWnCA on December 11, 2007, 12:16:47 PM
it is supposed to be plumbed to the top of the carb...

Just another ugly line to run.   :(
Title: Re: Fuel pump ?
Post by: Marcsrollin on December 11, 2007, 01:14:04 PM
I have the holley blue and have never had a problem with it. Someone I know was running the clay smith and the piece that goes into the motor broke off and destroyed the timing chain! I wonder who that was ? But he did go back and they did make it right with him so that says alot about there customer service.
Title: Re: Fuel pump ?
Post by: Blue on December 11, 2007, 01:58:23 PM
I have the holley blue and have never had a problem with it. Someone I know was running the clay smith and the piece that goes into the motor broke off and destroyed the timing chain! I wonder who that was ? But he did go back and they did make it right with him so that says alot about there customer service.

I don't think the fuel pump was soley the blame on that one.
Title: Re: Fuel pump ?
Post by: Marcsrollin on December 11, 2007, 02:08:37 PM
I don't think the fuel pump was soley the blame on that one.

Hopefully he'll chime in and tell us.
Title: Re: Fuel pump ?
Post by: Heatseeker on December 11, 2007, 02:37:37 PM
...You say it regulates to a point?  At what point do you need a regulator on a carbed motor?

A mechanical pump will only pump as fast as the engine is turning. So when at idle, it's not working very hard. When RPM/demand goes up, the pump starts moving some fuel.(Old auto pumps used to stop pumping when line pressure built up to a set pressure and would start pumping when the pressure fell back off, although I don't know if the Clay Smith pumps do this or not) An electric pump pumps like crazy all the time. That's what I meant by 'self regulates'.

I feel that you should always run a regulator in a high perf application . The best regulators are bypass style IMO. That way, there's nothing between your pump and your carbs.

Title: Re: Fuel pump ?
Post by: Blue on December 11, 2007, 04:32:48 PM
Hopefully he'll chime in and tell us.

I read 8k+ rpm had a little to do with it.
Title: Re: Fuel pump ?
Post by: Marcsrollin on December 11, 2007, 04:37:11 PM
There is no way that thing spun 8k. I saw the peices and it looks to me that the pump gave out and took the timing chain with it.
Title: Re: Fuel pump ?
Post by: Ralph Brunt on December 11, 2007, 06:42:28 PM
I read 8k+ rpm had a little to do with it.
hahaha 8 grand now thats flockin funny
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