1982 Mariner 90 stalls

[Morgangee]

I'm a newbie, and don't know much about outboards so please bear with me. I've searched the topics of past messages but don't think I've found a solution to my problem, so here goes...<br /><br />I have a 1982 Mariner 90, model 70900. It seems to start fine when cold, and runs great for about 10-15 minutes. Then, the motor completely stalls, and won't start again. It will turn over (electric start) slowly but won't start, and it almost feels like the battery has no charge. After it rests for some time, it will start back up again. We've checked the battery and connections, and their is no problem there and the power trim will still work while its not running. We brought the starter in, and it is working properly. <br /><br />Any thoughts about what I should be looking at next?

 

[Elmer Fudge]

Re: 1982 Mariner 90 stalls

Check your tank and see if it's venting correctly, if it is not, that could be the cause of you stalling.<br /> Have you tried it with a different battery?<br />I once had the problem where the trim motor and everything else worked just fine but the battery did'nt produce enough power to start the engine,even though it showed just over 12 volts.<br />I purchased a new battery and never looked back.

 

[Morgangee]

Re: 1982 Mariner 90 stalls

EF,<br /><br />Thanks for the reply. I haven't checked the gas tank ventilation, I will give it a shot. I have tried 2 different batteries, both of which tested fine before using on the boat, but encountered the same fate with both of them.<br /><br />Any other suggestions if its not the tank ventilation?

 

[funpilot]

Re: 1982 Mariner 90 stalls

The fact that it turns over slowly when warm frightens me a bit... I'm thinking something is heating up and restricting the movement of the piston(s) in the cylinder. I think a compression test might be in order to see if a ring has gone bad and welded a thin layer of aluminum in the cylinder.<br /><br />You could try starting the engine to loosen it up, letting it warm for a bit, and then shutting down, and pulling it through by hand with a starter rope. Note the force required. Then, after it dies, try pulling it by hand again, and see if it is any different.<br /><br />Good luck

 

[Elmer Fudge]

Re: 1982 Mariner 90 stalls

You could also try cleaning the battery terminals and the connections to the starter motor.<br /><br />Like funpilot said have the cylinders compression tested.<br /><br />Try doing all the little things first, like maybe checking the spark plugs and their wire connections and so forth.