Engine dies under load.

[Unregistered]

I have an 1974 Ericson 35 with a late model Atomic 4. Over the last year I have had a problem with the engine missing sporadically and then finally sputtering to a stop. I can usually start the engine again but it will do the same thing a short time later. Most recently, the engine will idle fine while I am moored but when I put the engine in gear and run the engine under load the engine speed will not increase, even though I give it full throttle. As soon as I shift it into gear it will slow down and stop. If I put it back in neutral I can rev up the engine to 3500 RPM or more. I am getting adequate spark from spark plugs and coil wire. I have taken the spark plugs out it appears to be adequate compression. I do have what I believe is the original metal fuel tank. I had a new stainless steel exhaust system and all new wiring, alternator, carb and fuel pump rebuilt, and new gauges installed in 1999. I have not used the boat much in the last two years but now I want to use it more and want to make sure my engine will run reliably.

I have replaced the water fuel separator with a new unit, replaced the coil, ignition points, rotor distributor cap, condenser, spark plugs, spark plug wires, coil wire and siphoned out most of the old gas and put in new gas. Changed the oil (no gas or water in the oil). I checked the distributor to make sure the springs and fly weights are functioning properly and it appears they are.

I will adjust the timing and dwell to make sure they are set optimally.

I have also purchased a MMI mechanical fuel pump rebuild kit and a new MMI carburetor which I will install this week.

I am wondering whether I should rebuild the mechanical fuel pump or install an electric fuel pump?

I am wondering if I should put in the electronic ignition?

Should I suspect the fuel tank is giving me problems?

Should these steps fix my problem?

[marthur]

Been there, done that!

Others (perhaps Don) will give a more exhaustive answer, but you might be interested in hearing about our fix to exactly those symptoms.

Our a-4 idled and ran well but had no power and would die in gear. The problem was a speck of grit in the main jet of the carb. I removed, disassembled and cleaned the carb and the problem cleared immediately with no return.

Our 1977 gas tank was not a problem, it was just 30 years accumulation of gunk in the carb.

ma

[Bob Wieber]

It sounds as though the 'sputtering and stopping' symptoms occured prior to your recent maintenance activities and current lack of power. If so, I would suspect that you have 2 plug wires reversed. This has happened to many others since the engine will idle well even with (at least) #'s 2 and 3 reversed. As I recall, the order should be 1,2,4,3.