Installed Promax modded Holleys, 6 pack fuel lines and Carter M6903 mech fuel pump
- Thread starter biomedtechguy
- Start date
- Local time
- 6:14 PM
- Joined
- Mar 28, 2014
- Messages
- 33,795
- Reaction score
- 53,668
- Location
- South Louisiana
That looks like a crescent wrench to work on the fuel fitting that goes into the float bowl, right?
Right now I have been using an adjustable crescent wrench.
What size should I start with to get what you have in the picture?
Also, once I got the needle and seat fixed, I was very disappointed to find how wrong I was about my "no fuel leaks" prediction.
The factory washer that goes between the fuel fitting and fuel/float bowl surface is paper thin, and steel. The ones that come with the Promax fuel lines are about 2-3 times thicker, a little thinner that a quarter, and 2 leaked badly, one just a bit.
I had 2 of my 3 original steel washers and swapped them in place of the aluminum ones Promax provided. Boom! No leaks.
I had to get the 3rd one from Ace Hardware, it is a paper type material, but it works.
Promax is sending me 3 nylon washers that I will try one of them on the front carb in place of the "paper" one.
Last steps are readjust the float level in the rear carb, adjust the throttle plate rod that connects the outboard carbs, and then check one last time for leaks.
I also have a T vacuum fitting for my FOB distributor, so the line that runs to the choke diaphragm can be split to the distributor too. Don at FOB says the distributor MUST get its vacuum signal from MANIFOLD vacuum. The Promax center carb metering block eliminates the vacuum tube for metered vacuum, which I was making do with working the choke diaphragm. Seems like my vacuum drops off when I split it.
- Local time
- 6:14 PM
- Joined
- Mar 28, 2014
- Messages
- 33,795
- Reaction score
- 53,668
- Location
- South Louisiana
All done with basic installation. Carbs currently as set from Promax. All leaks taken care of.
I still have to fine tune it, but the ride was nice. A little rich at idle, but I haven't touched any of the 6 idle mixture screws.
LOVE the
Carter M6903 mech fuel pump!
Enjoy!
I still have to fine tune it, but the ride was nice. A little rich at idle, but I haven't touched any of the 6 idle mixture screws.
LOVE the
Carter M6903 mech fuel pump! Enjoy!
hangn0ut
Well-Known Member
Looks good. Sounds like it's at 400 rpm. Up the idle speed!
- Local time
- 6:14 PM
- Joined
- Mar 28, 2014
- Messages
- 33,795
- Reaction score
- 53,668
- Location
- South Louisiana
That is 900+ RPMs...
292°/.509 Purple Stripe cam....
68 HEMI GTS
Well-Known Member
You don’t need and special tools, tighten the rear with the carb loose or off and use the bottom tee to seperate any time you gotta pull the carb
- Local time
- 6:14 PM
- Joined
- Mar 28, 2014
- Messages
- 33,795
- Reaction score
- 53,668
- Location
- South Louisiana
Yeah, that's pretty much what I did.
If not for the problems I had which seem inherent in the silver aluminum washers that Promax provided, I would have finished a couple of hours earlier since I had to go "find" a 3rd replacement washer to go along with the 2 factory steel thin washers I had, plus the time involved in removing and replacing carbs in order to be certain the fittings were tight.
747mopar
Well-Known Member
AWESOME!!!!
Hope you have better luck with your Carter pump, mine didn't even last a year before it dropped the pump arm in my oil pan! That was after a failed Holley (at least it lasted 3 years). One thing I learned is most pumps now days have way small inlet and outlets, I bought the only American Made pump I could find the last time around, still running and has much larger ports (3/8"NPT).
Hope you have better luck with your Carter pump, mine didn't even last a year before it dropped the pump arm in my oil pan! That was after a failed Holley (at least it lasted 3 years). One thing I learned is most pumps now days have way small inlet and outlets, I bought the only American Made pump I could find the last time around, still running and has much larger ports (3/8"NPT).
- Local time
- 6:14 PM
- Joined
- Mar 28, 2014
- Messages
- 33,795
- Reaction score
- 53,668
- Location
- South Louisiana
Which one?
The Carter M6903 is legendary for street strip performance, and I bought it from Mancini 2 years ago. Made in USA
That tool is mainly for disassembly on a stock setup to hold the inlet nut while you break free the fuel line with a flair nut wrench.
If you find a better way to hold it let me know.
That's a sweet setup you have, good luck with it.
If you find a better way to hold it let me know.
That's a sweet setup you have, good luck with it.
- Local time
- 6:14 PM
- Joined
- Mar 28, 2014
- Messages
- 33,795
- Reaction score
- 53,668
- Location
- South Louisiana
That makes sense. Dealing with those fittings on the stock fuel lines was always a challenge.
Although I didn't have any leaking problems or other problems with the stock fuel lines, and I even bought a spare stock upper 3 carbs fuel line set, one problem I had was working with the fuel bowl inlet stock fitting and the flare fittings that went into them.
Overall, the -6 AN fittings system is easier to work with.
747mopar
Well-Known Member
That's the one I bought, I looked for a label saying where it was made and found nothing but mine was bought more recently then yours. It wallowed the pin hole out that holds the pump arm. Could have been just one poor casting???? The thing that bothers me is I've had a few different brands in hand and can't find any difference outside of the finish.
- Local time
- 6:14 PM
- Joined
- Mar 28, 2014
- Messages
- 33,795
- Reaction score
- 53,668
- Location
- South Louisiana
Well my fuel pump that I removed was working with no problem other than if the car sat more than 10 days it took about 20+ seconds of cranking to fire. If less time had passed, no delay.
I am pretty sure the Carter has resolved that problem, but I won't know for a few weeks since I'm about to go to Crusin the Coast.
Similar threads
