LM318 Fuel pump replacement (upgrade)

[Mac32]

Now that I am running her after 5 years of sitting idle it seems that the little things are starting to come loose or breaking like the fuel pump.

So here is my question, for the first time ever I had my fuel vapor sensor go off, guess what there was fuel vapor. Apparently I have the original Carter mechanical fuel pumps that came on the engines (34 years of service, not bad) decide to leak.

So here is my question, in 1976 and before the fuel pumps just had a vent hole at the top for the diaphragm vent. so if it went bad this is where it would dribble fuel and this is still how they use them in auto motive world. But in the 80's the marine world switched to a vent tube with a return line that routed back up to the spark arrestor.

Here is my problem, I can get a nice hi performance replacement pump or the exact same thing (factory original) for around $35 or I can get the upgrade for about $150 each plus the extra fittings for the spark arrestor and for hose upgrade for $20. Times this by two and its $320 vs $70.

I know I am going to get the typical lecture about my family's safety here so please refrain I am not a dumb nut, I understand, probably more than most. This is why I will probably upgrade everything next season.

But I am curious who all is aware of this on this forum that is running these old boats and who already upgraded? I also wonder if I am over thinking this one because I had one problem in 15years on 34 year old equipment, but had other safety equipment do its job and set off the danger alarm.

And just in case anyone is wondering, yes I am a very conscious boater and put my own sniffer down in the bilge AND take a cursory look with a flashlight at the entire engine compartment for signs of anything loose or leaking both before and after each and every cruise.

[prowlersfish]

Go with the up grade . I find it hard to belive you can find a marine replacement for 35 bucks. Are you sure the pumps are OEM ,even back in the 60s they had diffrent pumps then automotive . I beleved they used a duel duel diafram pump with a glass catch bowl insed of venting outside the pump on . when nyou saw gas in the bowl it was time to change the pump . I guess this was on fords and gm

Looking at replacement pumps for 318 marine they sure look Like auto type pumps with a vent tube stuck on them ifyour 35 buck pump has the tube I would go that route and get the kit

With the NEW fuel (10% corn ) you will find pumps and hose life will be a lot shorter . may be agood time to change pumps

[Mac32]

Found it!! Here is the direct replacement. It has same casting as I have but with the vent tube.

http://woodys-auto-supply.com/auto-part ... CAR-M60980

They also sell kits with this pump with the spark arrestor and tubing for about $300 but we are smarter than that and dont need new arrestors, but just a added hose attachment.

Just as reference this is the old one I have:
http://woodys-auto-supply.com/auto-part ... =CAR-M6902

Maybe the previous owner replaced them and painted it the oem chrysler blue just to fool me?

[prowlersfish]

Thats the way to go. you can buy a lot of hose and fitting to fit the arestor for the $250 bucks saved . I would get 2 while you can .

[gjrylands]

My '69 Trojan had 318's. I bought that boat in '77 and I'm sure the fuel pumps on the engines were original. They did not have vents running to the flame arrestors, and there were no glass bowls to catch fuel if the diaphragm leaked. If the diaphragm leaks, fuel would spill into the bilge. Fuel pumps are reliable, but they can and do fail. That is why they were updated. To replace an old fuel pump with the same type OEM pump would be foolish. Not many things worse then a fire at sea.

[Mac32]

Just a quick update.....Found the cross reference for these pumps at auto zone (yes with the vent loop to carb) for $48... and I am happy to report they work just fine.

[larryeddington]

To Mac32;

Would you still have the autozone reference for the carter fuel pump for 318s?

[prowlersfish]

Just take the carter number in to the store , make sure the replacement has a vent tube as they change venders all the time . heres the carter number .

Carter M6902


You also may want to check With bob at becon marine