murdered6.2

Hopefully this is in the right section of this forum. I know im new and i dont have the biggest baddest boat not sure if i really have any buisness on this site with the boat i have but i was hoping to solve a problem.

I have a 1997 Baja Hammer with 7.4 mercruiser and carter carb. The engine keeps flooding out. I removed the carburetor and rebuilt it I have rebuilt several carburetors in the past so im fairly certain i rebuilt this one right eventhough this is my first carter style carb to rebuild. I reinstalled the carb. on the boat and ran it and same thing happens after a few miles the engine bogs, black smokes and dies, not missfires, no erratic rpm just slowly bogs and dies. When you open the hatch over the engine you can smell fuel vapors. If you let it sit for a little while with the throttle open it will eventually fire back up after quite a bit of cranking. uppon closer inspection i noticed that there is another set of butterflies on the secondary barrels that have counterweights on either side. They sit in a trough on either side of the secondary barrels, not sure if you guys know what i am talking about but i assume most/ if not all carter afb's are like this. Anyway the troughs that the counterweights are sitting in are full of fuel. I checked the vent hose comming from the fuel pump to the spark arrestor and its dry. i even drained the troughs and started it back up, it runs for a few miles and dies again same outcome fuel in the troughs. I removed the hose and ran it into a suitable container and retested. same outcome no fuel from the hose so i know its no my mechanical fuel pump leaking fuel into the carburetor.

Im brand new to boats but i have a lot of mechanical skills on vehicles. Im not really old enough to know much about carburetors and anything you cant hook a computer up to to diagnose but i am resourcefull and im looking to learn. Its almost impossible to get anyone where i live to rebuild a carburetor, they are all dead or dont want to mess with it.

I just bought this boat knowing it had a flooding problem among a few others, for the price i paid it was worth the risk especially knowing what im looking at to fix it. So far i have installed a delco 100 amp alternator cleaned and protected all electrical connections (solving 90 percent of the intermittant gremlins), installed a new starter, installed a perko battery switch and three new batteries, new engine blower fan and changed all filters. Im slowly getting this thing back into shape, It still needs a new water pump because the bearings are a little loose but the sea pump works good. I have yet to change all the fluids, but the belts and all hoses are new even exhaust hoses, water manifolds have been rebuilt recently. I still have an intermittant problem with the outdrive trim not working all the time but if you keep pressing the button it will start to work again. Not sure if its a relay or a sticking motor but my main concern is the flooding condition so i can finally install new plugs and finish tuning this thing up. Then i can move on to the other concerns and eventually add the fun stuff like a better radio and speakers.
Has anyone ran into a problem like this on a carter style carb? I could install a new carb on this thing but i prefer to fix it if possible. This winter i plan on installing a better intake and carb anyway, i just need this thing to make it through the season more than a few miles at a time.

If anyone has ran into something like this please let me know what to check. I ran back and checked the old carb top cover gasket with the new one and it is identical. So i guess i might have a cracked carb body or some sort of seal im not seeing causing the concern. I was just hoping i could get some insight on if this is a common problem or what the deal is with this carburetor. Thanks in advace sorry so long but i wanted to give as much detail as i can hopefully this isnt too confusing.

FIXX

iTrader: (2)

weigh the floats,may be filling up with fuel..

tinman565

Put a holley on it...easy to fix...easy to get parts....good looking carb.

Greenkeeper

X2 on the Holley, get the carter off of your property . They bring bad karma.

tinman565

hahaha...lol @ "get the carter off of your property"

apollard

I rebuilt my Weber WFB (same as the Carter design from what I hear), and I found it to be touchy in the float adjustment. If the float drop was too much, it stuck open. Recheck both float settings, and make sure the floats are good (both weigh the same, both show no signs of fluid in them if they are brass).

Once I got that set, purrs like a kitten at idle, and runs great WFO.

FWIW, while Holleys are good carb, I've had the same thing happen on 4150s used on cars.

ezstriper

yes the floats are finiky, but you could also have a fuel pressure issue, seen stock pumps get really high some times..also make sure you have a good filter to keep crap from getting to needle and seats and also causing this issue..Rob

mrv8outboard

I hope the starter and alternator were for a marine use and not automotive! Put a fuel pressure gauge in line to the carb and check the pressure. If you find the pressure is higher that specification you need a spacer between the pump and the block. they are usually plastic and 3/16ths thick. Just did one that the customer had the carb rebuilt then replaced for flooding, then the fuel pump twice with no luck. Checked the pressure found it to be 10 psi, put the spacer in and 8 psi and no flooding.

But back to the starter and alternator. marine components are spark and flame arrested. This is so the fumes in the bilge do not ignite by a spark from them.

Just food for thought.

blue thunder

If the diaphram in the fuel pump ruptures the carb will suck raw fuel from the tattletale hose. That will give you all the symptoms you describe plus one more. You will have fuel in your crankcase oil. The level will be high and it will smell like fuel.

apollard

Carters don't use fuel pump diaphrams, they use piston type pumps. If it leaks in any way, the leak would be back into the fuel bowl, not the intake.