She's leaning out, Fuel Pump and tubing???

[RickR]

Engine in avatar (502, max rpm 5700)

She's leaning out. I've changed the filter and already installed a larger Carter mechanical fuel pump on the stock Merc belt driven fuel/water pump assembly.

Not sure if it is due to the ethanol or the Carter getting weak but (at the carb) my 1100 RPM pressure is 4.5 and from 3500 to 4000 it drops below 4. I cannot check above 4000 because "The Boss" refuses to drive WOT offshore :eek: At WOT engine is dropping off and leaning out.

I am considering a Holley Marine (Blue w/external regulator, w/dash and oil pressure switch) installed in line with the Carter. That I would only have to turn the electric pump on when running above cruising speed.

I would like to keep everything Coast Guard compliant so I plan on using OE 3/8" hose to the Holley pump then 3/8 Stainless tubing thru Carter and to the carb.
Any advice???
THANKS!

Pic is from yesterday :dolphin:

[gcarter]

Why not run the Holley Blue only?

I've had very good success w/them.
You can add a safety switch.

[mrfixxall]

I have in the past boat ive worked on have installed a electric fuel pump in line with the mechanical fuel pump. my choice would be aeromotive marine fuel pump. you need to install it as low in the hull as possible, then i installed a nos switch to a relay that was throttle activated so it would turn on when at wot so you dont have to run the fuel pump to a seperate switch..

if you have two fuel outlets in your tank you could also run a seperate fuel pump and t it off at the fuel inlet at the carb,theirs a special check valve fitting you need to install so the higher pressuer wont interfrer with the low pressuer pump..

[RickR]

gcarter
I want to use the 5psi switch for safety. Do not want to have to prime the oil system every time I start the engine. I will try the Holley only, with some temporary plumbing and see how it works out.

mrfixxall
Fuel tank in the 22 just has one pickup. I used in line mechanical and electric in my high school hot rod and it worked great. Same problem, the Q jet overwhelmed the mechanical pump.
What are the advantages of the Aeromotive pump?

[mrfixxall]

gcarter
I want to use the 5psi switch for safety. Do not want to have to prime the oil system every time I start the engine. I will try the Holley only, with some temporary plumbing and see how it works out.
mrfixxall
Fuel tank in the 22 just has one pickup. I used in line mechanical and electric in my high school hot rod and it worked great. Same problem, the Q jet overwhelmed the mechanical pump.
What are the advantages of the Aeromotive pump?

Their not as noisy as the holly blue pump,their a inline pump that make a easier and cleaner instlation,also they have heatsinks molded into the body of the fuel pump so it stays cooler.i usually mount the pump in the bottom of the hull..

cp sells them check them out.

http://www.cpperformance.com/products/Fuel_Systems/fuel-pumps-electric.htm

[RickR]

Has anyone used one of these. Keith Eickert Mechanical Fuel Pump Base

http://www.cpperformance.com/detail.aspx?ID=939

[MOP]

Has anyone used one of these. Keith Eickert Mechanical Fuel Pump Base

http://www.cpperformance.com/detail.aspx?ID=939

Looks like a good deal, stock base porting is to small to allow enough fuel flow @WOT on a big cube engine.

[BigGrizzly]

The Keith pump is a good pump. I have a problem with your low fuel pressure at 1100 too. The fuel pressure should be 7-8. the floats should hold it from dilution. The volume is the main issue and the holley should have enough of bothI never run less then 3/8 fuel line. My 502 has AN10 and 1/2 pickup, you don't need that big. I uae an electric gauge for testing on the run. For a temporary solution you could use a mechanical for a temp test, this mite help

[RickR]

grizz
You got me thinking, I wonder if the cam lobe on the seawater/fuel pump has worn down (it has 1200 hours on it)???????
Anyone know what the lobe lift should be?

[donzi2287]

I have the blue Holly only and I'm happy with it. It is on a 502/500hp.

[mrfixxall]

grizz
You got me thinking, I wonder if the cam lobe on the seawater/fuel pump has worn down (it has 1200 hours on it)???????
Anyone know what the lobe lift should be?

Have you ever checked the oil in the seapump? Alot of people dont know about the oil in their and could have worn the lobe down. But now that im thinking the pump usually locks up before that happens..

[RickR]

mrfixxal
My gear lube gets contaminated with gasoline so I change it every year.
I had OK pressure when I changed the base of the Carter Pump over to the 110GPH unit. But now pressure is dropping off.

Due to the seawater pump turning faster than the crank (smaller pulley) and twice the speed of a cam driven pump, the fuel pump lever might have less stroke. This in turn might be causing an issue with the diaphrams which might be weak due to wear, age or ethanol. I'll pull the pump and check for wear on the lobe.

Poodle
Does you pump have a 90 degree puke tube fitting?????

[BigGrizzly]

Rick, I don't like the sound of contamination. This is not good. !200 hours, and I though I used my boat a lot.:worthy:

[RickR]

Can you use aluminum tubing for a fuel line in a saltwater boat?
Will a standard flare tool work on Stainless tubing?

[gcarter]

Can you use aluminum tubing for a fuel line in a saltwater boat?
Will a standard flare tool work on Stainless tubing?

I've had issues w/SST tubing. Particularly splitting when flaring, also very hard to form.
I've always used copper. it works well w/a double flare tool, it's very malable and forgiving. It's also very corrosion resistant and available anywhere..

[RickR]

gcarter
Did you paint the copper? Does it turn green when exposed to saltwater????

My current plan is to install a Holley 130 GPH mechanical base (on the Carter top) with a Holley 12-704 regulator. I will also increase the size of the fuel lines and try to open up the fittings coming out of the tank.

[mrfixxall]

mrfixxal
My gear lube gets contaminated with gasoline so I change it every year.
I had OK pressure when I changed the base of the Carter Pump over to the 110GPH unit. But now pressure is dropping off.
Due to the seawater pump turning faster than the crank (smaller pulley) and twice the speed of a cam driven pump, the fuel pump lever might have less stroke. This in turn might be causing an issue with the diaphrams which might be weak due to wear, age or ethanol. I'll pull the pump and check for wear on the lobe.
Poodle
Does you pump have a 90 degree puke tube fitting?????

Rick,

Your old fuel pump may have had a bad seal in it to contaminat the oil in the seapump.
If your turning higher rpms with the new engine you may want to look into a bigger seapump pully to slow it down a bit,remember your also speeding up the water flow to which wont allow the engine to get the proper cooling.

I wouls also go with a bigger fuel feed line at the tank.(if its a 22 classic) i would install a electric fuel pump in the ski locker to feed the mechanical fuel pump.thats a long haul to supply that motor you have with a mechanical pump. as for fuel lines,i usually use -10 steel braded line or the blue coaste guard approved rubber fuel line with push lock fittings.

[RickR]

Finally got "The Other Boat" finished so I got started on the 22.

She was leaning out due to the small filters in the Holley being clogged with varnish from evaporated fuel.

Odd gauge readings were from a bad gauge:shocking:

Cam on pump assembly was not worn, gear lube was not contaminated.

I have always had a lean issue with the 502 at WOT so I installed a Holley 130 GPH base on the fuel/seawater pump assembly with a Holley 34R-11577B regulator. I also drilled out all the brass fittings to 5/16 ID (including the tank pickup which was 1/4") and replaced the 5/16 stainless tubing with 3/8" A1 hose.

Now I have a rock steady 6psi fuel pressure at the carb inlet (even with a short, 10 Micron, filter)

Before, the lean condition was causing a stumble @ WOT and the oil temp would climb hotter than I wold like (270*) Now stumble is gone ;) and oil temp maintains at 240*.

HP500 Clone. Intake valve center line @ 111* compression 9.1/1

Measuring the hole in the needle and seats looks like they are .097" (Viton)
Is that large enough?

I am running Merc's staggered jets on the 800CFM, I have not checked the plugs :( They have always fouled out if I let the idle go below Mercs spec of 950 in gear at idle.
Primary Port 81 Starboard 75
Secondary Port 89 Starboard 93
That sound about right?

[gcarter]

Can you use aluminum tubing for a fuel line in a saltwater boat?
Will a standard flare tool work on Stainless tubing?
It's really difficult to do a double seal on SST tubing.
IMHO, aluminum tubing is kind of fragile for fuel lines.

[BUIZILLA]

i've never agreed with the Merc staggered jet theory on an open plenum intake...

you still run PV's? if so, 89/93's are wayyyyyyyy tooo fat

just IMO

[gcarter]

[quote=RickR;500839]gcarter
Did you paint the copper? Does it turn green when exposed to saltwater????
quote]
Sorry, I didn't see this question before.
Yes, I paint them after priming. The paint holds up very well.

[RickR]

Buz
6.5s in the primary, none in the secondaries. It is a Holley 4150 off of a HP500. Last I checked > 12" vacuum at idle.

[BUIZILLA]

check on .110-.120 seats (somewhere i've got some .130-140 alky seats)

you may not agree, but get the largest seats you can front and back, and run 82 front and 88 rear jets and get back to me... that should cure the tip in stumble and you'll have fuel for top end.. if you have access to an LM1 then the rest is cake...

you have a staggered jet total now of 338 with small seats

I propose a total of 340 but more available fuel with the bigger seats

338/4 = 84.5 vs 340/4/ = 85 average = starters from there

I leaned out fuzzy's 4 sizes and it went from 76 GPS in salt to 79.9 in fresh... :shades: just ask Tripper :outtahere: