1978 85hp merc outboard. only runs good cold

[chendley]

I have a 1978 85hp merc outboard that has sat for a year or two, it runs great at first but if we go accross the lake and shut it down then fire it up again and try to go it stalls. we have to run it at a low speed for about 5 minutes then we can usually get it to open up. this is the same every time we take it out. Any ideas ??

 

[corm]

Re: 1978 85hp merc outboard. only runs good cold

Hi<br />I read a post by the Marine Doctor a bit ago where He said the gas in Canada is good for 14 days. Well the same is true for the gas in the US.<br />The problem that you are having I think is the gas is boiling out of your carbs after you shut the motor off. The motor will gain in temperature after you shut it off to the point where the gas level in your carbs becomes real low. It takes a bit for the fuel pump to catch up. You could try squeezing the primer bulb to fill the carbs by hand before you start the motor to see if this is happening to you. Hope it is that simple.

 

[andrewkafp]

Re: 1978 85hp merc outboard. only runs good cold

Geez Corm..<br />14 days <br />We keep our milk longer than that <br />The Merc Manual says it starts losing quality after 30, but the consensus on iboats forums is about 4-6 weeks. You can add some fuel conditioner, but me being a bit of a whimp, throw it back in the car After 2 weeks and always use fresh stuff.<br />Company cars can run on ANYTHING...

 

[corm]

Re: 1978 85hp merc outboard. only runs good cold

Milk don't last that long in our house. <br />I should explain that my reference is based on my old motors like my 1976 150 hp IL6. I run it with the timing advanced way up and it will ping bad on 2wk old gas in the hot weather. I will put some Turbo-Blue race gas in to boost it if I have a lot of gas(which is seldom) left. I always run premiumin this motor. It will boil the gas out after a hard run up the river and some beach time. The new motors run on most anything, but I grew up with the IL6s and don't own a motor with a thermostate in it. The wife wants a 4 stroke for the poontoon boat so that will change soon. Which is ok because then I will have a place to dump all the gas that the aromatics have evaporated off lowering the octane. Now it goes in my old Ford truck at times. We use to put xylene and something else in our gas to kick it up some but that is nasty stuff, but fun.