1976 70HP evinrude stalling issues.

I have a 1976 70 HP evinrude model # 70673D
I took it out for its first run of the year, the boat is new to me but was bought off of my brother. So first got it in the water, took about 5 minutes to start it up, idled for a bit, tried puting it in reverse and it bogged down and died. Tried again and got it going, put it into gear and took off, ran fine for about 20 minutes but we stopped for a small break in the middle of the lake. So i tried restarting it and it would either not start or start and idle pretty low for a few seconds then bog down and die again. Eventually it would almost never start without cranking it and lifting the cold start at the same time, and as along as the cold start was engaged it would idle for a while, once i take cold start off it bogs down and dies again. So every so often it would idle on its own long enough to attempt to put it into gear, i tried easing into it but it would just sputter and die, also tried flooring it but it would just sputter and die. Seems to me like an idling problem or a fuel delivery problem but im really mostly ignorant about boats.

So for a summary it will not idle without cold start engaged, when trying to put it into gear it will die, every so often reverse will work (which is how i ended up getting back to the dock from the middle of the lake, all in reverse.

Any ideas of what the problem is let me know.

Thanks in advance

Re: 1976 70HP evinrude stalling issues.

Sounds like engine is starving for fuel! Continue use this way will cause a lean condition and eventually burning yer powerhead up! When was the last time carb/s were overhauled? Is fuel pump supplying enough fuel? Is fuel filter clean? Just a few things to check out. Post yer results!

Re: 1976 70HP evinrude stalling issues.

Well that there is one of the problems, i dont know how to go about checking these kinds of things, ive never even looked under the cap of a boat engine until i bought this boat a few weeks ago.

Re: 1976 70HP evinrude stalling issues.

Ok so we need to go through the basics first. With cowling removed, find yer fuel pump and remove the fuel hose that supplies fuel to carbs. Now remove plug wires to prevent engine from starting! while spinning engine with key, is the fuel pump pulsing out fuel? (NO!) Pulse hose broke or missing, Diaphram week or in need of replacing, Trash in fuel tank or lines!. (Yes) Overhaul carb/s with new carb kits and floats! Check the first things and then post yer results. Whatever needs to be done, we will walk you through it! Good luck and welcome to iboats!