Six Pack issues and rebuilding

[HP_Cuda]

I'm still scratching my head over having a motor being over-rev'd and then the fuel pump just basically floods the bejesus out of the carbs.

So I guess after you let off at 60mph and 2 car lengths behind the car died? That kinda makes sense if that happened and then you had a stuck float.

What kind of fuel pump you running? Holley Red pump? Mallory 110?

As Cryco said I'd use the Holley rebuild kits and do them all at once.

B

[tommyg29]

Im using a mallory pump, and yes when I just let off the gas the engine seemed like it was only running/loping on about 4 cylinders as I coasted home.
I read online more than once that even the holley kits typically have gaskets that have extra holes or sometimes you have to punch them yourself.
Never done a full rebuild on any carb other than for a small engine (lawnmower/trimmers)

[HP_Cuda]

Tommy

You will find they are pretty straight forward. If you have any questions please post up pics and ask any questions I and others will gladly help you out.

 
B

[tommyg29]

I have all 3 carbs sitting on my workbench and have the float bowls pulled. Everything looks fairly clean...no gunk or varnish.
Local parts stores dont have the rebuild kit so now looking online.

[HP_Cuda]

I would clean everything and

1) replace the needle and seats
2) change out the gaskets
3) ensure no jets are clogged
4) Check the squiters for blockage
5) check the vacuum diaphrams and check balls if you have them

Put them back together and make sure there are no vacuum leaks and no binding in the linkages

B

[jimynick]

The most important part is checking the float height and operation. There's usually a paper float height gauge in the carb kit; read the instruction sheet that also usually comes with it and make sure the floats move easily through their range of movement with the attendant moving of the needles in and out of their seats. A fuel pressure gauge would be a good investment and plumb it into the feed line into the carbs. You don't want much more than 6-7psi or you can literally force the needle off the seat regardless of how good the carb is, so a regulator may also be req'd. Look at the silver lining to this Tommy; if you hadn't checked, you'd've totally ruined that engine very shortly AND now you don't need to worry about any nasty sludge buildup anymore! 

[tommyg29]

Thanks,
I use a regulator set about 6 psi (I also have a gauge just after the regulator).
I am shopping now for new oem type fuel lines since I kinked two of the links at the carb while removing them. The oem type are a PITA, but they look good and I like the stock look. It is a tribute car after all. Found several guys selling them on ebay, but... the rebuild kits are hard to find. I am looking for Holley part # 3-396 or 37-396.

I noticed my inboard list # is 4670 (it also has 2360 stamped next to it), which according to a model # list I found is for a 1971 440 auto trans flowing 355 cfm. Wish I had the manual version (#4669) but I cant imagine there's much difference.

What are the separate part #s for the inboard (1) and outboard (2) carbs?

[tommyg29]

I stopped by NAPA and I ordered part # 2-5529 which appears to be the right set, but for $37 it probably wont be.
Ill pick it up tomorrow and start comparing the parts, though OI have no idea the existing gaskets are correct. Its not like my carbs were running perfectly. They were very rich. Idled ok, but always a cloud of smoke when I punched it.
Any suggestions as to power valve and jet sizes?
Currently running jets at 80 and power valve is either 8 or 8.5
Jets in the promax equipped outboards are 86

Ok, now I need to know how to remove the floats. I unscrewed the two hinge screws but it wont come out. Is there a hinge pin hidden back there?

[HP_Cuda]

Typically there are four bolts in the corners that need to be taken out to remove the float bowl.

As for your power valve size should be half your max idle vacuum - so if you are pulling 13" then you can get away with a 6.5 power valve.

I'd check your jet sizes which seem to be maybe a bit high as well.

Here is some more reading:
How it works:
The power valve opens at low vacuum, such as at wide open throttle, and directs more fuel into the main power circuit. The valve itself is a small rubber diaphragm with a small coil spring. When opened, it allows fuel to flow through a calibrated opening in the metering block called the power valve channel restrictor. This restrictor determines the amount of additional fuel delivered to the engine.

Problems:
The incorrect size power valve, or a blown out power valve can cause problems such as poor fuel economy, black smoke emanating from your exhaust, dark or fouling spark plugs and a poor idle. If you suspect that your carburetor has a blown-out power valve, you can perform this simple test.

[HP_Cuda]

Tommy

I found this on napaonline:
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Carburetor-Kit/_/R-CRB25529_0186023125

and I believe this is the instruction set for your carb:
http://s7d9.scene7.com/is/content/GenuinePartsCompany/1787686pdf?$PDF$

It doesn't say what the contents are so you will have to tell us what power valve and jets you got with it.

B

[tommyg29]

Tommy

I found this on napaonline:
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Carburetor-Kit/_/R-CRB25529_0186023125

and I believe this is the instruction set for your carb:
http://s7d9.scene7.com/is/content/GenuinePartsCompany/1787686pdf?$PDF$

B

Yep,
Thats the exact kit I ordered and will have tomorrow. Seems most run a 6.5 power valve, and jets maybe 66 or 68.
I talked with the prior owner about those sizes and he said those were the sizes they needed to get it to run well. 
I have no idea what vacuum Im running. Where is that measured at?
And should I even need to remove the float. I cant get at the pin but if its this hard to remove it must be a ***** to get that pin and spring back in there behind the float.

[HP_Cuda]

You can measure the vacuum from the manifold or from the base of one of your carbs.

Jets seem close but will have to investigate further to see if you need to bump them up/down. I'm a little confused on the pin you are talking about - how bout a pic?. I would remove the float bowl so you can see the float and replace the gasket. As well there are directions in the prior post on how to set the needle and seat so you are close. Once you have the fuel hooked up again, you can check the site plug to see if the fuel level is just below it otherwise you will need a small adjustment on the needle and seat.

Hope that helps,
Bryan

[tommyg29]

Im referring to the actual float itself. The bowl and the carbs are already almost totally dismantled.

[HP_Cuda]

Gotcha - yeah no need to remove the float unless it's damaged.

 

[tommyg29]

or just to check for proper operation. The floats seem to operate ok, but the reason Im rebuilding the carbs in the first place was because my engine was totally flooded. One or more of the three inlet valves failed to shut

and another thing, how many questions do I get? 
A few more:
After studying the exploded diagrams and browsing ebays offerings, I realize none of my 3 fuel inlets contained the cylindrical filters and springs? like these:
http://www.ebay.com/itm/Mopar-Six-Pack-Fuel-Bowl-Fittings-Bronze-Filters-/291030961734?pt=Motors_Car_Truck_Parts_Accessories&hash=item43c2cc0e46&vxp=mtr
 Are they needed? Im thinking the lack of those bronze filters may have at least contributed to my problem. They seem like a last line of defense against any small bits of debris.
And if I have to pull this whole setup a few more times changing jets, etc, I will probably ruin my new set of $45 fuel lines, so I may put together a temporary rubber line setup until I have everything running just right.


PS
figured out how to get the floats out. Need to wear my "reading" glasses more often.