1976 Johnson 70HP dies on warm throttle up

It's very consistent. It starts and runs reasonably well for an old motor when cold, but, after it is warmed up if I stop and let it idle it will die as soon as I try to throttle up. It will not run on throttle up for a few minutes. After about 5 minutes of trying choking, using the warm up lever, squeezing the priming bulb, it starts up and runs fine when i throttle it up. It kinda seems like it's starving for fuel. I don't smell a bunch of gas like I would if it was flooded. <br /><br />Any ideas?

Re: 1976 Johnson 70HP dies on warm throttle up

did you find out what was wrong? I am having a similar proublem on my 78 70hp

Re: 1976 Johnson 70HP dies on warm throttle up

Not yet, but I am convined it is a caused by the fuel/air mix bieng too lean. After reading here a little I suspected gunk or something in the tank or fuel line so I put a can of Seafoam in the tank and sprayed some using a squirt bottle into the carbs while I had it hooked up to the water hose at home today. I am not sure if the seafoam helped, but I figured it could not hurt. <br /><br />This afternoon I took it out on the lake and discovered that if I hit the choke switch for a split second while I was trying to throttle up that it helped a lot. In fact, I hit the choke a few times for a half second at wide open throttle and it seemed to prime it better or something and it started running a whole lot better. It even quit stalling on me on throttle up. So, maybe there is some trash in the fuel line or filter somewhere? Or it could be the fuel pump is screwed up and needs to be rebuilt?<br /><br />If it keeps acting screwy I am going to clean or replace the fuel filter and rebuild or replace the fuel pump. I am new to fooling with outboards so the thing still looks like a brain to me when I take off the engine cover. <br /><br />You may want to try doing what I did and drive it around the lake at WOT and hit the choke every so often and see if it clears it up some.